HALLA_BOL

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.