WorksheetsTopic 8 Acids, Bases and Salts: Learning Outcomes
Total questions: 150
Worksheet time: 1hrs 15mins
Phenolphthalein and methyl orange are indicators. Which statement correctly gives their colours in acidic solutions?
Phenolphthalein pink; methyl orange yellow
Phenolphthalein colourless; methyl orange red
Phenolphthalein red; methyl orange blue
Phenolphthalein purple; methyl orange green
Phenolphthalein and methyl orange are indicators. Which statement correctly gives their colours in alkaline solutions?
Phenolphthalein pink; methyl orange yellow
Phenolphthalein colourless; methyl orange red
Phenolphthalein pink; methyl orange red
Phenolphthalein blue; methyl orange orange
What colour does methyl orange typically show in neutral solutions?
Red
Yellow
Orange
Green
Red and blue litmus papers are used to identify solution type. Which outcome matches an acidic solution?
Red litmus turns blue; blue litmus stays blue
Red litmus stays red; blue litmus turns red
Both litmus papers remain unchanged
Red litmus turns white; blue litmus turns yellow
Universal indicator is used to estimate pH. Which pH range indicates a strong acid according to the classification provided?
pH 0–2
pH 3–6
pH 7
pH 8–11
According to the classification provided, which pH range represents a weak acid?
pH 0–2
pH 3–6
pH 8–11
pH 12–14
Which pH value corresponds to a neutral solution in the given classification?
pH 5
pH 7
pH 9
pH 13
Which pH range indicates a weak alkali according to the provided classification?
pH 0–2
pH 3–6
pH 8–11
pH 12–14
Which pH range indicates a strong alkali according to the provided classification?
pH 0–2
pH 3–6
pH 7
pH 12–14
Using a pH meter to at least one decimal place improves data quality. Which is the most accurate pH recording?
pH 7
pH 7.0
pH about 7
Neutral
Acids dissolve in water to produce a specific ion. Which ion is produced?
Hydroxide, OH−(aq)
Hydrogen, H+(aq)
Sulfate, SO4 2−(aq)
Carbonate, CO3 2−(aq)
Alkalis dissolve in water to produce which ion?
Hydrogen ions, H+(aq)
Hydroxide ions, OH−(aq)
Nitrate ions, NO3 −(aq)
Ammonium ions, NH4 +(aq)
How does the concentration of hydrogen ions in an acidic solution affect pH?
Higher [H+] gives higher pH
Higher [H+] gives lower pH
[H+] does not change pH
Lower [H+] gives lower pH
Strong acids in water are described as completely ionised. Which is a correct example of a strong acid from the list given?
Ethanoic acid
Hydrochloric acid
Carbonic acid
Ammonia
Which pair lists strong alkalis from the examples provided?
Sodium hydroxide and potassium hydroxide
Calcium carbonate and sodium chloride
Ammonia and ethanoic acid
Hydrochloric acid and nitric acid
Weak acids are partially ionised in water. Which is an example of a weak acid listed?
Nitric acid
Sulfuric acid
Ethanoic acid
Sodium hydroxide
Which substance is given as an example of a weak alkali?
Potassium hydroxide
Ammonia
Hydrochloric acid
Carbonic acid
Which statement best distinguishes dilute from concentrated solutions as defined?
Dilute has low amount of solute; concentrated has high amount of solute
Dilute has low amount of solvent; concentrated has high amount of solvent
Dilute has low temperature; concentrated has high temperature
Dilute has low pH; concentrated has high pH
Neutralisation is described as the reaction between H+(aq) and OH−(aq) to produce water. What is the correct ionic equation?
H+(aq) + OH−(aq) → H2O(l)
H+(aq) + Cl−(aq) → HCl(aq)
Na+(aq) + OH−(aq) → NaOH(aq)
H2(g) + O2(g) → H2O(l)
During neutralisation, what is the expected temperature change described?
Endothermic; temperature decreases
Exothermic; heat is given out
No change in temperature
Depends only on indicator colour
What is recalled about a base in this material?
A base is a soluble hydroxide only
A base is a metal oxide or hydroxide that neutralises acids
A base is any compound with carbon
A base must have pH above 12
Which statement correctly links alkalis to bases?
All bases are alkalis because they are solids
An alkali is a soluble base
An alkali is an insoluble oxide
An alkali must be neutral
Which general reaction is expected when hydrochloric, sulfuric, or nitric acids react with metals according to the outcomes list?
They produce bases directly
They form salts (specific to metal and acid)
They turn into carbonates
They become neutral without products
Hydrogen gas test is described. What is the correct test outcome when a lighted splint is applied?
Blue flame sustained
A popping sound
Turns splint green
No observable change
Carbon dioxide test is described with limewater. What is the positive result?
Limewater turns red
Limewater becomes milky
Limewater stays colourless
Limewater turns blue
What is a salt as defined here?
A compound where hydroxide ions replace hydrogen ions
A compound formed when some or all hydrogen ions in an acid are replaced by metal ions or ammonium ions
A compound containing only sodium and chlorine
A compound made only from neutralisation of weak acids
According to the notes, most Group 1 and Group 2, aluminium and zinc salts share a common appearance. Which is correct?
They are generally coloured
They are generally white and give colourless solutions if they dissolve
They are black solids that give blue solutions
They are always insoluble
What is stated about transition metal salts compared to Group 1 and 2 salts?
Transition metal salts are generally colourless
Transition metal salts are generally coloured
Transition metal salts are always white
Transition metal salts never dissolve
One method to prepare pure dry samples of soluble salts is listed as adding excess insoluble substance to acid. What is the purpose of adding excess?
To ensure no acid remains and to allow filtration of the excess solid
To change the indicator colour permanently
To make the solution alkaline
To increase the amount of water produced
Which listed method involves adding alkali to acid in the presence of an indicator?
Titration
Filtration
Crystallisation
Distillation
When preparing salts by neutralisation using an indicator, what follow-up step is suggested to obtain a pure sample?
Leave the indicator in for colour
Remove the indicator using charcoal or repeat without indicator
Add more acid until colour intensifies
Add metal to consume hydroxide ions
Which drying methods are mentioned for preparing dry salts?
High-temperature furnace only
Desiccator or low-temperature oven or between two sheets of filter paper
Sunlight and wind exposure
Freeze-drying only
What safety awareness is emphasised about laboratory risks?
Ignore hazard labels if supervised
Assess potential risks, including those shown on GHS/CLP chemical hazard labels
Use only flammable chemicals to learn safety
Focus solely on temperature monitoring
Which hazard categories are explicitly associated with GHS/CLP labels in the material?
Toxic, corrosive, flammable, explosive, caution
Neutral, safe, harmless, edible
Only radioactive
Only biological
Which statement best describes what acids do when dissolved in water?
They release OH− ions (hydroxide ions).
They release H+ ions (hydrogen ions/protons).
They become neutral and stop reacting.
They form solid salts immediately without ions.
Which pH value range correctly matches the type of solution?
Acid: pH > 7; Alkali: pH < 7; Neutral: pH = 7
Acid: pH < 7; Alkali: pH > 7; Neutral: pH = 7
Acid: pH = 7; Alkali: pH < 7; Neutral: pH > 7
Acid: pH > 14; Alkali: pH < 0; Neutral: pH = 1
When soluble bases (alkalis) dissolve in water, what ions are released?
H+ ions (protons)
OH− ions (hydroxide ions)
Cl− ions (chloride ions)
Na+ ions (sodium ions)
Which list shows common everyday examples of acids?
Citric acid in lemons, ethanoic acid in vinegar, sulfuric acid in battery acid
Magnesium hydroxide in antacids, copper oxide, iron oxide
Sodium chloride, glucose, water
Calcium carbonate in chalk, oxygen gas, nitrogen gas
Which property is typical of acids according to the recap?
Slippery/soapy feel
Strong sweet taste
Sour taste and corrosive
Smells strongly of ammonia
Which property is typical of bases according to the recap?
Sour taste and corrosive
Slippery/soapy feel and corrosive
Odourless and non-corrosive
Produce H+ ions in water
Match the hazard pictogram description to its hazard class: Skull and crossbones, Gas cylinder, Test-tubes dripping onto hand and bench.
Acutely toxic; gas under pressure; corrosive
Corrosive; acutely toxic; gas under pressure
Gas under pressure; corrosive; acutely toxic
Moderate hazard; oxidising; flammable
Which safety action is appropriate when using flammable substances in the laboratory?
Use naked flames to speed reactions.
Avoid naked flames to reduce ignition risk.
Wear no PPE to avoid contamination.
Store near oxidising agents to stabilise them.
According to the international hazard symbols system shown, what is the main advantage of using pictograms?
They replace all official hazard statements.
They are recognised worldwide and avoid language issues.
They only apply within one country’s laboratories.
They are used only for acids and bases.
Which hazard is indicated by the pictogram showing test tubes dripping onto a hand and a surface?
Flammable
Corrosive
Gas under pressure
Oxidising
What is the correct definition of an indicator in this context?
A device that measures temperature.
A chemical that gives a colour change in acidic, alkaline and neutral solutions.
A solution that neutralises acids.
A pigment used to colour laboratory glassware.
A student tests a solution with red and blue litmus paper. The red paper stays red and the blue paper turns red. What does this suggest about the solution?
It is acidic.
It is neutral.
It is alkaline.
It is both acidic and alkaline.
Which colour changes are expected for litmus papers in a neutral solution?
Red litmus turns blue; blue litmus turns red.
Red litmus stays red; blue litmus stays blue.
Red litmus turns redder; blue litmus becomes colourless.
Both papers turn purple.
Which pair correctly shows litmus colours in an alkaline solution?
Red litmus: red; Blue litmus: red
Red litmus: blue; Blue litmus: blue
Red litmus: red; Blue litmus: blue
Red litmus: blue; Blue litmus: red
Phenolphthalein is added to three solutions. One turns pink, one stays colourless, and one remains colourless even after standing. Based on typical indicator behaviour, which set correctly identifies the solutions as alkali, acid, and neutral?
Pink = acid, Colourless = alkali, Colourless (stable) = neutral
Pink = alkali, Colourless = acid, Colourless (stable) = neutral
Pink = neutral, Colourless = acid, Colourless (stable) = alkali
Pink = alkali, Colourless = neutral, Colourless (stable) = acid
Methyl orange shows different colours depending on pH. Which row correctly matches its colour in acid, alkali, and neutral?
Acid = Red, Alkali = Yellow, Neutral = Orange
Acid = Yellow, Alkali = Red, Neutral = Orange
Acid = Orange, Alkali = Yellow, Neutral = Red
Acid = Red, Alkali = Orange, Neutral = Yellow
According to the universal indicator scale, what colour indicates strong acids (pH 0–2)?
Green
Red
Blue
Purple
A solution shows green on universal indicator. Which description best fits this solution?
Strong acid, pH 0–2
Neutral, pH 7
Weak acid, pH 3–6
Strong alkali, pH 12–14
Washing-up liquid and ammonia are examples of which category on the pH scale, and what typical universal indicator colour range do they show?
Weak acids; orange to yellow
Neutral solutions; green
Weak alkalis; green-blue to blue
Strong alkalis; dark blue to purple
A sample turns dark blue to purple with universal indicator. Which description is most appropriate?
Weak alkali, pH 8–11
Neutral, pH 7
Strong alkali, pH 12–14
Weak acid, pH 3–6
Which statement correctly compares the information given by universal indicator paper versus single indicators like litmus or methyl orange?
Universal indicator only tells if a substance is acidic or alkaline without indicating strength.
Universal indicator indicates the strength (pH) of acids and alkalis, while single indicators mainly show acidic vs alkaline.
Single indicators provide exact pH values, while universal indicator only shows colour without meaning.
Neither universal indicator nor single indicators can distinguish between acid and alkali.
Which pairing of everyday examples and pH category is correct based on the universal indicator information?
Vinegar and lemon juice — strong alkali (pH 12–14)
Tap water and milk — neutral (pH 7)
Soap powder and sodium hydroxide — weak acid (pH 3–6)
Car battery acid and stomach acid — weak alkali (pH 8–11)
Which statement best explains why a pH meter is preferred over universal indicator paper for measuring the pH of strong acid solutions?
A pH meter gives color changes that are easier to compare across samples.
A pH meter can record pH to two decimal places and accurately measure very low (even negative) pH values.
Indicator paper is too expensive compared to a pH meter.
Indicator paper works only for bases and not for acids.
A 2 mol/dm^3 solution of sulfuric acid is mentioned as having a pH of −0.6. What conclusion does this support about strong acids?
Strong acids can only have pH values between 0 and 1.
Strong acids may have negative pH values that indicators cannot measure accurately.
Strong acids always have a neutral pH of 7.
Strong acids cannot be measured by any instrument.
Match each acid to its common use based on the table: Hydrochloric acid, Sulfuric acid, Nitric acid, Ethanoic acid, Carbonic acid.
Hydrochloric acid—car battery acid; Sulfuric acid—stomach acid; Nitric acid—bubbly soft drinks; Ethanoic acid—synthesis of explosives & fertilisers; Carbonic acid—vinegar
Hydrochloric acid—stomach acid; Sulfuric acid—car battery acid; Nitric acid—synthesis of explosives & fertilisers; Ethanoic acid—vinegar; Carbonic acid—bubbly soft drinks
Hydrochloric acid—vinegar; Sulfuric acid—bubbly soft drinks; Nitric acid—stomach acid; Ethanoic acid—car battery acid; Carbonic acid—synthesis of explosives & fertilisers
Hydrochloric acid—synthesis of explosives & fertilisers; Sulfuric acid—stomach acid; Nitric acid—car battery acid; Ethanoic acid—bubbly soft drinks; Carbonic acid—vinegar
Which pair correctly matches an acid to both its formula and strength?
Ethanoic acid—H2SO4—Strong
Carbonic acid—H2CO3—Weak
Nitric acid—HCl—Weak
Sulfuric acid—CH3COOH—Strong
You need to measure the pH of an unknown solution suspected to be a very strong acid. Plan the most appropriate procedure based on the material.
Use universal indicator paper because it gives a quick and highly precise reading to two decimal places.
Use a pH meter to obtain an accurate reading to two decimal places, since strong acids may have negative pH values.
Dilute the sample until its pH reaches 7, then use indicator paper for an exact measurement.
Estimate pH by smell, then confirm with litmus paper for negative pH values.
Which statement best describes ionisation of a strong acid in water?
It partially forms hydrogen ions and leaves most molecules unchanged
It completely dissociates to produce hydrogen ions (H+) and its conjugate anions
It forms hydroxide ions (OH−) and raises the pH
It does not react with water and remains as neutral molecules
In the equations showing acid ionisation, what do the two opposite arrows (⇄) indicate for ethanoic acid (CH3COOH) and carbonic acid (H2CO3)?
Complete ionisation to products
No ionisation occurs
Partial ionisation establishing an equilibrium
Ionisation only at high temperatures
Which acid listed produces two hydrogen ions per formula unit when it ionises in water?
Hydrochloric acid (HCl)
Nitric acid (HNO3)
Sulfuric acid (H2SO4)
Ethanoic acid (CH3COOH)
Refer to the diagram of beakers illustrating hydrochloric acid and ethanoic acid ionisation. Which observation correctly matches the type of acid shown?
Hydrochloric acid beaker shows mostly intact HCl molecules; ethanoic acid beaker shows only ions
Hydrochloric acid beaker shows many H+ and Cl− ions; ethanoic acid beaker shows a mix of CH3COOH molecules and CH3COO−/H+ ions
Both beakers show equal numbers of intact molecules and ions
Ethanoic acid beaker shows only OH− ions formed from water
Which statement links hydrogen ion concentration to pH for acidic solutions?
A higher number of H+ ions gives a lower pH value
A higher number of H+ ions gives a higher pH value
H+ concentration does not affect pH
Only OH− concentration determines pH
What is the best definition of an alkali based on the material?
A base that is insoluble in water
A soluble base that produces OH−(aq) ions in water
Any substance that produces H+(aq) ions
A neutral salt formed from an acid–base reaction
Which equation represents a weak alkali because it ionises partially in water?
NaOH(aq) → Na+(aq) + OH−(aq)
KOH(aq) → K+(aq) + OH−(aq)
NH3(aq) + H2O(l) ⇄ NH4+(aq) + OH−(aq)
HCl(aq) → H+(aq) + Cl−(aq)
Which summary statement correctly distinguishes acids from alkalis when dissolved in water?
Acids and alkalis both produce H+(aq) ions
Acids produce H+(aq) ions, while alkalis produce OH−(aq) ions
Acids produce OH−(aq) ions, while alkalis produce H+(aq) ions
Neither acids nor alkalis produce ions in water
Which alkali is identified as strong in the table and commonly associated with bleach use?
Magnesium hydroxide
Ammonia (NH3(aq)/NH4OH)
Sodium hydroxide (NaOH)
Potassium hydroxide (KOH)
According to the uses listed, which alkali is found in indigestion tablets?
Sodium hydroxide (NaOH)
Magnesium hydroxide [Mg(OH)2]
Ammonia solution (NH4OH)
Potassium hydroxide (KOH)
Which statement correctly distinguishes strength from concentration for acids/alkalis?
Strength refers to the number of molecules dissolved per dm3, while concentration is measured by pH.
Strength is a measure of ionisation and is measured by pH, while concentration is the number of moles dissolved per dm3.
Strength and concentration both measure ionisation and are expressed in mol/dm3.
Concentration is the amount of ionisation, while strength is the number of moles per dm3.
A solution described as concentrated has which characteristic based on the definition provided?
A large number of acid particles dissolved per unit volume
A small number of acid particles dissolved per unit volume
Complete ionisation regardless of amount dissolved
A high pH because it contains fewer hydrogen ions
Ammonia solution (NH3(aq)/NH4OH) is classified as which type of alkali and commonly used for what?
Strong; bleach
Weak; cleaning fluids
Strong; indigestion tablets
Weak; neutralising stomach acid
Which statement best defines neutralisation in chemistry?
The reaction between two acids to form a base and water
The reaction between an acid and an alkali producing a salt and water
The reaction between a metal and oxygen producing an oxide
The reaction between an alkali and a salt producing an acid
What is the correct ionic equation for a neutralisation reaction?
H+ (aq) + OH− (aq) → H2O (l)
H+ (aq) + Cl− (aq) → HCl (aq)
Na+ (aq) + OH− (aq) → NaOH (aq)
Ca2+ (aq) + CO3 2− (aq) → CaCO3 (s)
A person has indigestion due to excess hydrochloric acid in the stomach. Based on neutralisation examples, which substance in tablets helps relieve this by acting as a base?
Sodium chloride
Magnesium oxide
Calcium carbonate only from lime
Hydrochloric acid
All neutralisation reactions share which energy change characteristic?
They are endothermic, so the temperature decreases
They are exothermic, so the temperature increases
They release no energy, so the temperature stays constant
They alternate between endothermic and exothermic depending on the acid used
Which statement best defines a salt in chemistry?
A salt is any compound containing chlorine.
A salt is the compound formed when some or all hydrogen ions in an acid are replaced by metal ions or ammonium ions.
A salt is a compound produced when a base gains hydrogen ions.
A salt is any ionic compound that contains oxygen.
When hydrochloric acid reacts to form a salt, what is the name of the salt family and the characteristic anion present?
Sulfates containing SO42− ions
Nitrates containing NO3− ions
Chlorides containing Cl− ions
Ethanoates containing CH3COO− ions
Salts have two words in their names. Which pair correctly describes the source of each word?
First = non‑metal, Second = base
First = metal or ammonium, Second = derived from the acid
First = acid, Second = base used
First = gas produced, Second = acid used
Which general reaction produces salt and hydrogen gas?
Acid + Base
Acid + Metal
Acid + Alkali
Acid + Carbonate
Which products are formed when an acid reacts with a carbonate?
Salt and hydrogen
Salt and water
Salt, water, and carbon dioxide
Ammonium salt only
According to the general rule for oxides, how are metal oxides and non‑metal oxides typically classified?
Metal oxides are acidic; non‑metal oxides are basic.
Metal oxides are basic; non‑metal oxides are acidic.
Both metal and non‑metal oxides are neutral.
Metal oxides are amphoteric; non‑metal oxides are neutral.
Which reaction illustrates a typical metal oxide reacting with an acid to form a salt and water?
Hydrochloric acid + copper oxide → copper chloride + water
Carbon dioxide + sodium hydroxide → sodium carbonate + water
Sulfuric acid + calcium carbonate → calcium sulfate + water + carbon dioxide
Nitric acid + ammonia → ammonium nitrate
Which statement about exceptions to oxide classification is correct?
Water (hydrogen oxide) and carbon monoxide are neutral and do not behave as acidic or basic oxides.
Water is an acidic oxide, and carbon monoxide is a basic oxide.
Both water and carbon monoxide are strongly acidic oxides.
Both water and carbon monoxide are amphoteric oxides.
Which test and positive result correctly identify hydrogen gas?
Bubble through limewater; it turns milky white.
Apply a lighted splint; a squeaky pop is heard.
Expose to glowing splint; it relights.
Use cobalt chloride paper; it turns pink.
How is carbon dioxide gas tested and what positive result is observed?
Apply a lighted splint; loud bang.
Bubble gas through limewater; limewater changes from colourless to milky white.
Expose to glowing splint; it relights.
Pass over copper(II) oxide; solution turns blue.
Which observation should be recorded when a gas forms during an acid reaction?
Solid disappears and a solution forms
Bubbles of gas produced
Heat is absorbed
Colourless precipitate appears
Most acid reactions are exothermic. Which statement best describes the observation for an exothermic reaction?
Heat is released
Heat is absorbed
No temperature change
Cooling is required to proceed
According to the colour table, which compound is a black solid?
Copper(II) carbonate
Hydrated copper(II) sulfate
Copper(II) oxide
Copper(II) salts in solution
When a solid metal, base, or carbonate reacts with an acid, what is the typical observation?
Effervescence with a blue solution
Solid disappears and a solution is produced
Formation of a black precipitate
No visible change
Which set correctly matches substances to their stated colours?
Copper(II) carbonate: green solid; Hydrated copper(II) sulfate: blue crystals
Copper(II) carbonate: black solid; Copper(II) salts in solution: blue crystals
Hydrated copper(II) sulfate: colourless solution; Group 1 compounds: green solids
Copper(II) oxide: blue solution; Group 1 compounds: blue crystals
Predict the products when zinc reacts with sulfuric acid, based on the provided practice equations.
Zinc chloride and hydrogen
Zinc sulfate and hydrogen
Zinc oxide and water
Zinc sulfate and carbon dioxide
Copper(II) carbonate reacts with hydrochloric acid. Which complete set of products is given in the material?
Copper sulfate and hydrogen
Copper chloride and hydrogen
Copper chloride, water, and carbon dioxide
Copper oxide, water, and carbon dioxide
Which salt type is formed by hydrochloric acid?
Chlorides
Sulfates
Nitrates
Ethanoates
Which salt example corresponds to sulfuric acid according to the table: Hydrochloric acid → chlorides → sodium chloride; Sulfuric acid → sulfates → ?; Nitric acid → nitrates → potassium nitrate; Ethanoic acid → ethanoates → calcium ethanoate.
Sodium chloride
Magnesium sulfate
Potassium nitrate
Calcium ethanoate
According to the summary table, nitric acid produces which type of salts?
Ethanoates
Nitrates
Sulfates
Carbonates
What do all acid reactions produce?
Only hydrogen gas
Only water
A salt (and sometimes other products)
Only carbon dioxide
Identify the products in the word equation: Magnesium + hydrochloric acid → ?. Use the pattern for metals reacting with dilute acid.
Magnesium sulfate only
Magnesium chloride + hydrogen
Magnesium oxide + water
Magnesium nitrate + carbon dioxide
Which balanced symbol equation matches: Iron + sulfuric acid → iron sulfate + hydrogen?
Fe + H2SO4 → FeSO4 + H2
Fe + 2HCl → FeCl2 + H2
Fe + 2HNO3 → Fe(NO3)2 + H2O
Fe + H2SO4 → Fe2(SO4)3 + H2
Select the correct products for: Calcium carbonate + hydrochloric acid → ?.
Calcium sulfate + hydrogen
Calcium chloride + water + carbon dioxide
Calcium nitrate + water
Calcium ethanoate + hydrogen
Choose the balanced symbol equation for: Sodium carbonate + nitric acid → sodium nitrate + carbon dioxide + water.
Na2CO3 + HNO3 → NaNO3 + CO2 + H2O
Na2CO3 + 2HNO3 → 2NaNO3 + CO2 + H2O
Na2CO3 + 2HNO3 → NaNO3 + CO2 + H2O
Na2CO3 + HNO3 → 2NaNO3 + 2CO2 + H2O
In the reaction: Sodium hydrogen carbonate + sulfuric acid → ?, which set of products is correct?
Sodium sulfate + water + carbon dioxide
Sodium chloride + hydrogen
Sodium nitrate + oxygen
Sodium sulfate only
Which balanced symbol equation represents: Copper(II) oxide + nitric acid → copper nitrate + water?
CuO + H2SO4 → CuSO4 + H2O
CuO + 2HNO3 → Cu(NO3)2 + H2O
Cu + 2HNO3 → Cu(NO3)2 + H2
CuO + 2HCl → CuCl2 + H2O
Identify the balanced symbol equation for: Magnesium oxide + hydrochloric acid → magnesium chloride + water.
MgO + HCl → MgCl2 + H2O
Mg + 2HCl → MgCl2 + H2
MgO + 2HCl → MgCl2 + H2O
MgO + 2HNO3 → Mg(NO3)2 + H2O
Which equation correctly shows: Potassium hydroxide + sulfuric acid → potassium sulfate + water?
KOH + H2SO4 → K2SO4 + H2O
2KOH + H2SO4 → K2SO4 + 2H2O
K2O + H2SO4 → K2SO4 + H2O
KOH + 2HCl → KCl + H2O
What is the name given to the reaction between an acid and an alkali?
Combustion
Oxidation
Neutralisation
Electrolysis
According to the solubility rules, which statement is correct about ammonium, potassium, and sodium salts?
Only ammonium salts are soluble
All ammonium, potassium, and sodium salts are soluble
Potassium salts are insoluble unless heated
Sodium salts are soluble only in cold water
Which chloride is insoluble in both hot and cold water based on the solubility rules provided?
Lead(II) chloride
Silver chloride
Sodium chloride
Ammonium chloride
Most sulfates are soluble. Which combination correctly lists the exceptions described?
Calcium sulfate slightly soluble; barium sulfate and lead sulfate insoluble
Barium sulfate slightly soluble; calcium sulfate and lead sulfate insoluble
Lead sulfate slightly soluble; barium sulfate and calcium sulfate insoluble
Magnesium sulfate slightly soluble; barium sulfate and silver sulfate insoluble
Which carbonate is listed as soluble, contrary to the general rule that most carbonates are insoluble?
Calcium carbonate
Ammonium carbonate
Copper(II) carbonate
Lead(II) carbonate
Refer to the flowchart for preparing salts. If the desired salt is insoluble, which method should be used?
Use indicator method to neutralize acid and alkali
Use precipitation by mixing solutions containing the ions of the insoluble salt, then filter, wash, and dry
Use excess insoluble solid with acid, then evaporate to crystallize
Heat the salt strongly until it dissolves
When preparing a soluble salt using an insoluble base, what is the correct sequence according to the flowchart?
Add acid to alkali with indicator, then crystallize
Add excess insoluble solid to acid, filter off excess, evaporate the solution until ready to cool and crystallize
Mix two solutions to precipitate the salt, then wash and dry
Titrate without an indicator and collect the precipitate
Which method is recommended for obtaining a pure soluble salt when both the acid and alkali are soluble?
Precipitation method
Indicator method followed by repeating without indicator or removing indicator using charcoal
Adding excess insoluble solid and filtering
Heating directly until crystals form without evaporation
Which is NOT one of the listed methods for drying salt crystals?
Place in a desiccator
Place in a low temperature oven
Dry between two sheets of filter paper
Sun-dry at high temperature
Which type of oxides are classified as basic oxides?
Metal oxides
Non-metal oxides
Amphoteric oxides
Acidic oxides
Select the best example of a basic oxide from the list below.
Copper oxide
Sulfur dioxide
Carbon dioxide
Silicon dioxide
When solid green copper carbonate reacts with dilute sulfuric acid, which pair of observations is most likely?
The green solid remains unchanged; the solution stays colourless
The green solid disappears; bubbles of gas are produced
A red solid forms; the solution turns yellow
The solution becomes milky; no gas is produced
During the preparation of copper sulfate from copper carbonate and dilute sulfuric acid, what change occurs to the solution’s colour?
It stays colourless
It becomes blue
It turns green
It becomes pink
Why is copper sulfate not prepared by adding dilute sulfuric acid directly to copper metal?
Copper reacts too vigorously with sulfuric acid and explodes
Copper is an unreactive metal and will not react with dilute sulfuric acid
Copper forms a basic oxide that blocks the reaction
Copper dissolves to produce hydrogen gas instead
Which indicator result most clearly shows a solution is strongly alkaline in this experiment?
Red litmus turns red
Universal indicator turns orange
Phenolphthalein turns pink
Blue litmus turns red
According to the safety notes, which statement is correct about phenolphthalein?
It is an irritant to skin and eyes
It is highly flammable and listed under HAZCARD No32 & 40A
It is corrosive and requires gloves only
It is non-hazardous at 0.1 M
A student dips red litmus paper into sodium hydroxide solution. Based on the table, what colour should the paper become?
Blue
Red
Purple
Green
Water is tested with universal indicator paper. Using the observations table, what does the colour suggest about its pH nature?
Green indicates a neutral solution
Red indicates a strongly acidic solution
Purple indicates a strongly alkaline solution
Orange indicates a weakly acidic solution
Two unknown solutions give these results: Solution X turns blue litmus red and phenolphthalein colourless; Solution Y turns red litmus blue and phenolphthalein pink. Which classification is correct?
X is alkaline; Y is acidic
X is acidic; Y is alkaline
Both X and Y are neutral
Both X and Y are acidic
Which pair of solutions is mixed in this neutralisation experiment, and at what concentration?
Hydrochloric acid (HCl, 1M) and sodium hydroxide (NaOH, 1M)
Nitric acid (HNO3, 0.5M) and potassium hydroxide (KOH, 1M)
Sulfuric acid (H2SO4, 2M) and ammonia (NH3, 1M)
Ethanoic acid (CH3COOH, 1M) and calcium hydroxide (Ca(OH)2, 0.1M)
Before starting the reaction, which safety instruction is specifically stated for handling sodium hydroxide?
Wear eye protection; NaOH is corrosive to skin and eyes
Work in a fume hood; NaOH is highly volatile
Wear heat-resistant gloves; NaOH is flammable
Avoid using glassware; NaOH reacts with glass
According to the method, what volume of alkali is initially placed into the conical flask, and what is the volume added from the burette each step?
20 cm³ alkali; add 4 cm³ acid each step
40 cm³ alkali; add 8 cm³ acid each step
10 cm³ alkali; add 2 cm³ acid each step
25 cm³ alkali; add 5 cm³ acid each step
Using the results table (pH values), at approximately what total volume of acid added does the solution become neutral?
12 cm³
16 cm³
20 cm³
28 cm³
From the temperature data, what trend is observed as acid is added and where is the maximum temperature reached?
Temperature decreases steadily; maximum 30.0°C at 0 cm³
Temperature increases steadily to a peak then falls; maximum 34.0°C around 20 cm³
Temperature stays constant; maximum 31.0°C at 28 cm³
Temperature fluctuates randomly; maximum 26.5°C at 8 cm³
Which statement best describes how pH changes as acid is added, using the terms slightly and rapidly as requested?
pH increases slightly at first, then rapidly increases near 20 cm³
pH decreases slightly at first, then rapidly drops to pH 7 and 2.8 near 20 cm³, then decreases slightly in the acidic range
pH remains constant until 20 cm³, then rapidly increases
pH fluctuates slightly and rapidly without a pattern
What substance remains after the neutral sample is boiled to dryness following the reaction between hydrochloric acid and sodium hydroxide?
Water only
Sodium chloride (salt)
Hydrogen gas
Sodium carbonate
If 20 cm³ of 1M acid is required to neutralise the alkali used, how does this quantity compare to the original amount of alkali in the flask?
It is half the volume of alkali used
It is double the volume of alkali used
It is the same volume as the alkali used
It is one quarter of the volume of alkali used
Safety labels in this experiment state that 2M sulfuric acid is classified as which hazard category?
Corrosive to skin and eyes
Flammable solid
Irritant only
Non-hazardous at 2M
When magnesium ribbon reacts with dilute sulfuric acid, what gas is produced, confirmed by a squeaky pop with a lighted splint?
Oxygen
Hydrogen
Carbon dioxide
Nitrogen
Choose the correct balanced symbol equation for magnesium reacting with sulfuric acid.
Mg + H2SO4 → MgSO4 + H2
Mg + H2SO4 → Mg2SO4 + H2
Mg + H2SO4 → MgSO4 + H2O
Mg + 2H2SO4 → MgSO4 + 2H2
In the magnesium and sulfuric acid reaction, what is the observed colour of the solution after the reaction?
Colourless
Pale blue
Blue
Green
Copper oxide reacts with dilute sulfuric acid. Which observation correctly describes whether a gas is given off?
Yes, hydrogen gas is produced
Yes, carbon dioxide gas is produced
No gas is given off
A small amount of oxygen is released
Identify the correct word equation for the reaction between copper oxide and sulfuric acid.
Copper oxide + sulfuric acid → copper sulfate + water
Copper oxide + sulfuric acid → copper sulfate + hydrogen
Copper oxide + sulfuric acid → copper oxide + water
Copper oxide + sulfuric acid → copper carbonate + water
Select the balanced symbol equation for copper oxide reacting with sulfuric acid.
CuO + H2SO4 → CuSO4 + H2
CuO + H2SO4 → CuSO4 + H2O
Cu + H2SO4 → CuSO4 + H2
CuO + 2H2SO4 → Cu2SO4 + 2H2O
During the copper carbonate and sulfuric acid reaction, what test confirms the identity of the gas produced?
Squeaky pop with a lighted splint
Blue flame with a burning splint
Turns damp red litmus blue
Bubbling through limewater turns it milky white
What is the correct balanced symbol equation for copper carbonate reacting with sulfuric acid?
CuCO3 + H2SO4 → CuSO4 + H2
CuCO3 + H2SO4 → CuSO4 + H2O + CO2
CuCO3 + H2SO4 → CuO + H2O + CO2
CuCO3 + 2H2SO4 → CuSO4 + 2H2O + CO2
Match each reaction type with its characteristic product. Choose the best description based on the experiment results.
Acid–metal: salt + hydrogen
Acid–base (oxide): salt + water
Acid–carbonate: salt + water + carbon dioxide
Acid–metal: salt + oxygen
Which balanced symbol equation represents the reaction used to prepare copper sulfate from copper(II) carbonate and sulfuric acid?
CuCO3 + H2SO4 → CuSO4 + H2O + CO2
CuCO3 + HCl → CuCl2 + H2O + CO2
CuO + H2SO4 → CuSO4 + H2O
CuCO3 + H2SO4 → CuSO4 + 2H2O
In this experiment, why is copper(II) carbonate added until it is in excess?
To ensure all the acid has reacted
To increase the temperature of the solution
To make crystals form faster
To change copper sulfate to copper carbonate
Which observation indicates that copper(II) carbonate is in excess during the reaction?
Solid copper carbonate remains at the bottom and fizzing stops
The solution turns colorless and bubbles increase
The filter paper changes color and gas production continues
Crystals immediately appear while the mixture is boiling
What is the general name given to the solid trapped by the filter paper after filtration?
Residue
Filtrate
Precipitate
Solute
Why should the dilute sulfuric acid be warmed only for a short time and not boiled in Step 2?
Boiling may cause splashing and is unnecessary for reaction progress
Boiling improves accuracy of measurement
Boiling prevents copper carbonate from dissolving
Boiling ensures complete neutralisation
Which apparatus is best for accurately measuring 25 cm3 of dilute sulfuric acid for the experiment?
Pipette with a pi-pump attached
Measuring cylinder
Beaker
Conical flask
