WorksheetsExploring Chemical Reactions and Acids
Total questions: 10
Worksheet time: 5mins
What is the law of conservation of mass?
Mass can be created in chemical reactions.
Mass is conserved in chemical reactions; it cannot be created or destroyed.
Mass is only conserved in physical changes.
Mass can be destroyed during a reaction.
Define a chemical reaction and provide an example.
Dissolving salt in water: NaCl -> Na+ + Cl-
Rusting of iron: 4 Fe + 3 O2 -> 2 Fe2O3
Photosynthesis: 6 CO2 + 6 H2O -> C6H12O6 + 6 O2
An example of a chemical reaction is the combustion of methane: CH4 + 2 O2 -> CO2 + 2 H2O.
What are the signs that a chemical reaction has occurred?
No visible changes in the mixture
Change in the state of matter without heat
Signs of a chemical reaction include gas formation, color change, temperature change, precipitate formation, and odor change.
Formation of a solid without a reaction
Explain the difference between exothermic and endothermic reactions.
Both exothermic and endothermic reactions release energy.
Exothermic reactions occur only in gases; endothermic reactions occur only in liquids.
Exothermic reactions absorb energy; endothermic reactions release energy.
Exothermic reactions release energy; endothermic reactions absorb energy.
What is pH, and how is it measured?
pH indicates the concentration of oxygen in water, measured with oxygen meters.
pH is a measure of temperature, measured with thermometers.
pH is a measure of pressure, measured with barometers.
pH is a measure of acidity/alkalinity, measured with pH meters or indicator strips.
Describe the properties of acids and bases.
Bases donate protons and have a sour taste.
Acids and bases are both neutral and tasteless.
Acids donate protons and have a sour taste; bases accept protons and have a bitter taste.
Acids are slippery and have a sweet taste.
What is the neutralization reaction? Give an example.
An example of a neutralization reaction is the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH), which produces water (H2O) and sodium chloride (NaCl).
The reaction between hydrogen peroxide and baking soda.
The reaction between potassium chloride and water.
The reaction between vinegar and oil.
How do you identify a strong acid versus a weak acid?
Strong acids are always more concentrated than weak acids.
Strong acids do not conduct electricity in solution.
Strong acids fully dissociate in water; weak acids partially dissociate.
Weak acids have a higher pH than strong acids.
What role do catalysts play in chemical reactions?
Catalysts are consumed in the reaction and do not affect the outcome.
Catalysts change the products of the reaction to create new substances.
Catalysts slow down chemical reactions by increasing activation energy.
Catalysts speed up chemical reactions by lowering activation energy.
Explain the concept of molarity in relation to acids and bases.
Molarity measures the volume of a solution in milliliters.
Molarity is the temperature of a solution affecting acid strength.
Molarity is the concentration of a solution expressed as moles of solute per liter of solution, crucial for understanding the behavior of acids and bases.
Molarity is the weight of solute in grams per liter of solution.
