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WorksheetsExploring Chemistry Concepts
Total questions: 10
Worksheet time: 5mins
What is the law of conservation of mass in chemical reactions?
The total mass increases during a reaction.
Mass is only conserved in physical changes.
The total mass remains constant in chemical reactions.
Mass can be created in chemical reactions.
Define a chemical reaction and provide an example.
A chemical reaction is a physical change that does not involve any new substances, e.g., melting ice.
A chemical reaction is the mixing of two substances without any change, e.g., stirring sugar in water.
A chemical reaction is a process where reactants are converted into products, e.g., CH4 + 2 O2 → CO2 + 2 H2O.
A chemical reaction is a process that occurs only in living organisms, e.g., photosynthesis.
What are the signs that a chemical reaction has occurred?
Signs of a chemical reaction include gas formation, color change, temperature change, precipitate formation, and odor change.
Change in the shape of a container
Formation of a solid without a liquid
Increase in the volume of a gas without a reaction
Explain the difference between an acid and a base.
Acids have a pH above 7; bases have a pH below 7.
Acids are always liquid; bases are always solid.
Acids accept protons; bases donate protons.
Acids donate protons; bases accept protons.
What is the pH scale and what does it measure?
The pH scale measures the temperature of a solution.
The pH scale measures the density of a solution.
The pH scale indicates the color of a solution.
The pH scale measures the concentration of hydrogen ions in a solution.
Describe the process of neutralization between an acid and a base.
The process of neutralization between an acid and a base results in the formation of water and a salt.
Neutralization results in the formation of hydrogen gas and a base.
The reaction between an acid and a base creates a strong acid.
The process of neutralization produces only carbon dioxide.
What are the common properties of acids?
Common properties of acids include sour taste, ability to conduct electricity, proton donation, reaction with bases, and turning blue litmus paper red.
Turning red litmus paper blue
Ability to absorb heat
Bitter taste
What are the common properties of bases?
Feels rough and gritty
Tastes sweet and sour
Does not change the color of indicators
Common properties of bases include being slippery, having a bitter taste, changing the color of indicators, and reacting with acids.
How do you balance a chemical equation?
Add more atoms to one side without adjusting the other.
Change the chemical formula to match one side.
To balance a chemical equation, adjust the coefficients of the reactants and products to ensure the same number of each type of atom on both sides.
Ignore the number of atoms and focus on the charge.
What is the role of catalysts in chemical reactions?
Catalysts speed up chemical reactions by lowering activation energy.
Catalysts are consumed in the reaction and do not affect the outcome.
Catalysts slow down chemical reactions by increasing activation energy.
Catalysts change the products of the reaction to create new substances.
