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WorksheetsChemical Reactions and Equations
Total questions: 68
Worksheet time: 35mins
What are the five main types of chemical reactions?
Combination (Synthesis) Reactions, Decomposition Reactions, Single Replacement (Substitution) Reactions, Double Replacement (Metathesis) Reactions, Combustion Reactions
Oxidation Reactions
Acid-Base Reactions
Polymerization Reactions
How do you balance a chemical equation?
Adjust the coefficients of the compounds in the equation to ensure the number of atoms of each element is the same on both sides.
Multiply the subscripts of the compounds by different numbers
Count the number of vowels in the equation
Change the order of the compounds in the equation
What is stoichiometry in chemical reactions?
Stoichiometry in chemical reactions involves calculating the amounts of substances consumed and produced in a chemical reaction.
Stoichiometry is the study of the effects of chemicals on the human body.
Stoichiometry involves the study of the physical properties of chemical compounds.
Stoichiometry refers to the process of extracting metals from ores.
Explain the concept of limiting reactants in a chemical reaction.
Limiting reactants are the reactants that speed up a chemical reaction.
The concept of limiting reactants in a chemical reaction refers to the reactant that is completely consumed first, limiting the amount of product that can be formed.
Limiting reactants are the reactants that are not involved in a chemical reaction.
Limiting reactants are the reactants that are in excess in a chemical reaction.
Define oxidation and reduction in the context of redox reactions.
Oxidation is the process of reducing the oxidation state of a substance, while reduction is the process of oxidizing a substance.
Oxidation is the addition of protons to a substance, while reduction is the removal of protons from a substance.
Oxidation is the loss of electrons or an increase in oxidation state, while reduction is the gain of electrons or a decrease in oxidation state.
Oxidation is the gain of electrons or an increase in oxidation state, while reduction is the loss of electrons or a decrease in oxidation state.
What is the difference between a synthesis reaction and a decomposition reaction?
Synthesis reactions result in the formation of simpler substances, while decomposition reactions result in the combination of substances.
In a synthesis reaction, substances combine to form a new compound, whereas in a decomposition reaction, a compound breaks down into simpler substances.
In a synthesis reaction, substances break down into simpler substances, whereas in a decomposition reaction, a compound forms a new compound.
Synthesis reactions involve the breakdown of compounds, while decomposition reactions involve the formation of compounds.
Why is it important to balance chemical equations?
To ensure the law of conservation of mass is obeyed.
To waste time
To create confusion
To impress others
In a redox reaction, which element is oxidized and which is reduced?
The element that is oxidized loses electrons, and the element that is reduced gains electrons.
The element that is oxidized undergoes a decrease in oxidation state, and the element that is reduced undergoes an increase in oxidation state.
The element that is oxidized gains electrons, and the element that is reduced loses electrons.
The element that is oxidized is always a metal, and the element that is reduced is always a nonmetal.
What is the role of a catalyst in a chemical reaction?
A catalyst has no effect on the reaction rate.
A catalyst inhibits the reaction by increasing the activation energy barrier.
A catalyst changes the stoichiometry of the reaction.
A catalyst speeds up the reaction by lowering the activation energy barrier.
How does the Law of Conservation of Mass apply to chemical reactions?
The total mass of the reactants and products in chemical reactions can vary.
In chemical reactions, the total mass of the reactants must equal the total mass of the products.
The mass of the reactants can be greater than the mass of the products in chemical reactions.
The Law of Conservation of Mass does not apply to chemical reactions.
What is the difference between an exothermic and endothermic reaction?
The main difference is that exothermic reactions release heat, whereas endothermic reactions absorb heat.
Exothermic reactions and endothermic reactions both absorb heat.
Exothermic reactions and endothermic reactions both release heat.
Exothermic reactions absorb heat, whereas endothermic reactions release heat.
Explain the concept of molarity in relation to chemical reactions.
Molarity is the volume of solute per liter of solution
Molarity is the number of molecules of solute per liter of solution
Molarity is the number of moles of solute per liter of solution, used to quantify the concentration of substances in chemical reactions.
Molarity is the weight of solute per liter of solution
What is the purpose of using coefficients in a balanced chemical equation?
To add complexity to the equation
To confuse students
To ensure the law of conservation of mass is obeyed.
To make the equation look longer
How do you determine the mole ratio between reactants and products in a chemical reaction?
Look at the coefficients of the balanced chemical equation.
Consult a magic eight ball
Guess randomly
Count the number of atoms in each molecule
What is the difference between a single displacement reaction and a double displacement reaction?
The main difference is in the number of compounds involved and the rearrangement of elements.
The color of the reactants
The size of the reaction vessel
The temperature at which the reaction occurs
Describe the process of balancing a redox reaction using the half-reaction method.
Mixing all reactants together without considering half-reactions
Balancing only one side of the reaction
The process involves separating the reaction into two half-reactions, balancing each half-reaction separately, ensuring the number of electrons lost equals the number gained, and combining the balanced half-reactions to obtain the overall balanced redox reaction.
Ignoring the conservation of electrons
Rancidity is a process in which fat/oils smell due to the change process of
oxidation
reduction
displacement
neutralization
Colour of which metal changes to greem due to corrosion?
Cu
Al
Fe
Ag
Barium chloride on reacting with ammonium sulphate forms barium sulphate and ammonium chloride. Which of the following correctly represents the type of the reaction involved?
(i) Displacement reaction
(ii) Precipitation reaction
(iii) Combination reaction
(iv) Double displacement reaction
(a) (i) only
(b) (ii) only
(c) (iv) only
(d) (ii) and (iv)
Electrolysis of water is a decomposition reaction. The mole ratio of hydrogen and oxygen gases liberated during electrolysis of water is
(a) 1:1
(b) 2:1
(c) 4:1
(d) 1:2
Which among the following is(are) double displacement
reaction(s)?
(i) Pb + CuCl2 --> PbCl2 + Cu
(ii) Na2SO4 + BaCl2 --> BaSO4 + 2NaCl
(iii) C + O2 --> CO2
(iv) CH4 + 2O2 --> CO2 + 2H2O
(a) (i) and (iv)
(b) (ii) only
(c) (i) and (ii)
(d) (iii) and (iv)
Three beakers labelled as A, B and C each containing 25 mL
of water were taken. A small amount of NaOH, anhydrous
CuSO4 and NaCl were added to the beakers A, B and C
respectively. It was observed that there was an increase in
the temperature of the solutions contained in beakers A and B, whereas in case of beaker C, the temperature of the
solution falls. Which one of the following statement(s) is(are) correct?
(i) In beakers A and B, exothermic process has occurred.
(ii) In beakers A and B, endothermic process has occurred.
(iii) In beaker C exothermic process has occurred.
(iv) In beaker C endothermic process has occurred.
(a) (i) only
(b) (ii) only
(c) (i) and (iv)
(d) (ii) and (iii)
Which of the following statements about the given reaction are correct?
3Fe(s) + 4H2O(g) ® Fe3O4(s) + 4H2(g)
(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as oxidising agent
(a) (i), (ii) and (iii)
(b) (iii) and (iv)
(c) (i), (ii) and (iv)
(d) (ii) and (iv)
The following picture shows the heating of lead nitrate. On heating two gases are evolved, one is colourless and the other is brown in colour. Which gases are they?
Hydrogen and oxygen
Oxygen and nitrous oxide
Hydrogen and lead oxide
Oxygen and nitrogen dioxide
Hydrated ferrous sulphate is commonly known as ______.
Blue vitriol
Green vitrioll
Yellow vitrio
Brown vitriol
Which one of the following four metals would be displaced from its salt solution by the other three metals?
Li
Al
Ca
Pt
Which among the following element changes the color of the knife in this experiment?
Oxygen
Copper
Sulphur
Iron
What happens when a piece of Cu is put into a solution of magnesium chloride?
Cu displaces Mg.
Chlorine gas is liberated
No chemical reaction.
Colour of the solution changes to light green.
An iron nail is placed in a solution of copper sulphate. The nail is taken out after 10 minutes. The nail will be found to be covered with:
Brown deposit
Black deposit
White deposit
Yellow deposit
While performing an activity in the lab, Meera exhaled air into a colourless solution taken in a test tube. Suddenly its colour turned to milky white. Which among the following is the colourless solution?
Lime water
Soda water
Aqueous solution of NaOH
Aqueous solution of NaCl
Which of the following represents a combination reaction?
Reaction of zinc metal with copper sulphate solution.
Heating of lead nitrate.
.Burning of magnesium in air.
Reaction between silver nitrate and sodium chloride.
Which of the following behaviours is true about the solution obtained by mixing CaO with water?
Amphoteric solution
Basic solution
Acidic solution
Neutral solution
On passing CO₂ gas through the product formed by the reaction between CaO and H₂O, solution becomes which colour?
black
red
pink
white
Which of the following termed as reducing agent?
Which gives oxygen
Which removes oxygen
Which removes hydrogen
All of the above
Which of the following is termed as exothermic reaction?
Reaction in which heat is evolved
Reaction in which heat is absorbed
Reaction in which there is loss of oxygen
Reaction in which there is gain of hydrogen
How rancidity can be prevented?
By adding antioxidants in food
By adding more oxygen to food
By keeping food items in open
All of the above
Which of the following is termed as rancidity?
Reduction of oxygen present in food
Oxidation of sugar present in food
Oxidation of oil present in food
All of the above
Why are articles made of iron painted to prevent rust?
Paint makes articles made of iron beautiful
Paint prevents iron articles to come in contact with moisture present in air.
Paint prevents iron articles to getting sticky
All of the above
What happens when sodium sulphate solution is mixed with the solution of barium chloride?
No reaction takes place
Barium sulphate is formed
Sulphur dioxide gas is formed
Sodium sulphate is formed
What happens when carbon dioxide is passed in lime water?
Lime water turns milky because of formation of calcium carbonate
Lime water turns milky because of formation of water
Lime water turns red because of formation permanganate
Lime water turns red because of formation of copper sulphate
What happens when silver chloride is put under sunlight?
Silver metal and chlorine gas are formed
Silver metal and hydrogen gas are formed
Only silver metal is formed
Only hydrogen gas is formed
Which of the following product is formed when calcium oxide reacts with water?
Slaked lime
Carbon dioxide
Calcium oxide
Oxygen gas
Heating of ferrous sulphate gives which of the following product?
Ferric oxide
Sulphur dioxide
Sulphur trioxide
All of the above
What is the another name of quick lime?
Calcium hydroxide
Calcium oxide
Carbon dioxide
Sodium oxide
What happens when copper rod is dipped in iron sulphate solution :-
Copper displaces iron
Blue color of copper sulphate solution is obtained
No reaction takes place
Reaction is exothermic
Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:
Make the ribbon surface shinier
Remove the layer of magnesium oxide from the ribbon surface
Remove the layer of magnesium carbonate from the ribbon surface
Remove the moisture from the ribbon surface
The neutralization reaction between an acid and a base is a type of:
Double displacement reaction
Displacement reaction
Addition reaction
Decomposition reaction
The displacement reaction between iron (III) oxide and a metal X is used for welding the rail tracks. Here X is:
Copper granules
Magnesium ribbon
Sodium pellets
Aluminium dust
It is necessary to balance a chemical equation in order to satisfy the law of:
Conservation of motion
Conservation of momentum
Conservation of energy
Conservation of mass
When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:
Blue to green.
Green to blue.
Green to brown.
Green to yellow.
One of the following processes does not involve a chemical reaction. That is:
Melting of candle wax when heated
Burning of candle wax when heated
Digestion of food in our stomach
Ripening of banana
A chemical reaction does not involve:
Formation of new substances having entirely different properties than that of the reactants
Breaking of old chemical bonds and formation of new chemical bonds
Rearrangement of the atoms of reactants to form new products
Changing of the atoms of on element into those of another element to form new products
The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of:
Exothermic process
Endothermic process
Reversible process
Physical process
In which of the following process a chemical reaction has taken place?
Ice melts into water
A wet shirt got dried in sunlight
A brown layer is formed over iron rod kept in air
sugar getting dissolved in water
A chemical equation should be balanced to :
show conservation of energy
show conservation of mass
to make equation attractive
All of the above
Silver article turns black when kept in open for a few days due to formation of
H2S
AgS
AgSO4
Ag2S
Choose the incorrect statement from the following options about saving foods from rancidity.
keep food items in air tight containers
flushing food items with carbon dioxide
flushing food items with nitrogen
keep food items in air loose containers
Choose the correct balanced equation of barium chloride and aluminium sulphate.
3BaCl2+Al2(SO4)3→3BaSO4+2AlCl3
2BaCl2+Al2(SO4)3→2BaSO4+2AlCl3
6BaCl2+2Al2(SO4)3→6BaSO4+4AlCl3
none of the above
What is the process that is happening in this image ? And also give the name of the two gas that are present in two test tubes and the ratio they(gases) are present in .
process= thermal decomposition,
gases present=hydrogen,carbon dioxide, ratio=2:1
process=corrosion,
gases present=oxygen,hydroxide, ratio=2:1
process=electrolysis of hydrogen polyoxide
gases present=hydrogen,oxygen, ratio=2:1
process=electrolysis of water
gases present=hydrogen,oxygen,ratio=4:2
A solution of X is used for white washing walls. it reacts slowly with Y in air to form a thin layer of B on walls which gives walls a shiny finish. which of the following options correctly represents X,Y and B ?
X =slaked lime , Y = nitrogen , B=calcium oxide
X =Calcium Hydroxide, Y=Oxygen, B = Calcium carbonate
X= slaked lime, Y=Carbon oxide,B= calcium chloride
X= slaked lime,Y=Carbon dioxide,B=Calcium carbonate
which of the following observations helps to determine that a chemical reaction has taken place ?
change in state
change in color
change in temperature
all of the above
Which of the following statements about the given reaction are correct?
3Fe(s) + 4H2O(g) => Fe3O4(s) + 4H2(g)
(i) Iron metal is getting oxidised
(ii) Water is getting reduced
(iii) Water is acting as reducing agent
(iv) Water is acting as oxidising agent
(a) (i), (ii) and (iii)
(b) (iii) and (iv)
(c) (i), (ii) and (iv)
(d) (ii) and (iv)
Which of the following is not a physical change?
(a) Boiling of water to give water vapour
(b) Melting of ice to give water
(c) Dissolution of salt in water
(d) Combustion of Liquefied Petroleum Gas (LPG)
What are the substances on the left side called and right side of the chemical equation called respectively ?
products and reactants
groups and electrons
nothing
reactants and products
when does a chemical reaction take place ?
when a physical change occurs
when a chemical change occurs
both a and b
none of the above
