NEW
Font size
WorksheetsHALLA_BOL
Total questions: 10
Worksheet time: 5mins
What is a chemical reaction?
A chemical reaction is a process that only occurs in living organisms.
A chemical reaction is when substances are combined to form a mixture.
A chemical reaction is the mixing of two substances without any change.
A chemical reaction is a process where substances (reactants) are transformed into different substances (products) through the rearrangement of atoms.
Define a reactant and a product.
A reactant is a starting material in a chemical reaction, and a product is a substance produced from that reaction.
A reactant is a type of energy, and a product is a type of catalyst.
A reactant is a substance that cannot change, and a product is a substance that can change.
A reactant is a product of a chemical reaction, and a product is a starting material.
What is the law of conservation of mass?
Mass is only relevant in biological processes.
Mass can be created in chemical reactions.
Mass is conserved in chemical reactions; it cannot be created or destroyed.
Mass is lost during physical changes.
How do you balance a chemical equation?
Balance the number of atoms for each element on both sides of the equation using coefficients.
Add or remove elements to make the equation simpler.
Use equal signs to separate reactants and products.
Count only the number of molecules on each side.
What are the signs that a chemical reaction has occurred?
Formation of a solid without a liquid
Absence of any visible changes
Signs of a chemical reaction include gas formation, color change, temperature change, precipitate formation, and light or sound emission.
Change in the shape of a container
What is the difference between an exothermic and an endothermic reaction?
Both exothermic and endothermic reactions release energy.
Exothermic reactions do not involve energy changes; endothermic reactions do.
Exothermic reactions release energy; endothermic reactions absorb energy.
Exothermic reactions absorb energy; endothermic reactions release energy.
Give an example of a synthesis reaction.
2H2 + 2O2 -> 2H2O2
2H2 + O2 -> 2H2O
C + O2 -> CO2
H2 + O2 -> H2O2
What is a decomposition reaction?
A decomposition reaction is a reaction in which a compound breaks down into simpler substances.
A decomposition reaction involves the rearrangement of atoms without breaking any bonds.
A decomposition reaction is a process where energy is released without any change in the substance.
A decomposition reaction is when two compounds combine to form a single product.
Explain what a catalyst does in a chemical reaction.
A catalyst is a substance that is consumed in a chemical reaction.
A catalyst speeds up a chemical reaction by lowering the activation energy.
A catalyst changes the products of a chemical reaction.
A catalyst slows down a chemical reaction by increasing the activation energy.
What is the role of energy in chemical reactions?
Energy is solely responsible for the color change in reactions.
Energy is only needed for physical changes, not chemical reactions.
Energy has no impact on the speed of chemical reactions.
Energy plays a critical role in breaking and forming chemical bonds during reactions.
