4.4.4.25 Chemistry-Top Notch Released STAAR

Front

What is a chemical reaction?

Back

A process in which substances (reactants) undergo a transformation to form new substances (products) with different properties.

Front

What are indicators of a chemical reaction?

Back

Indicators include color change, temperature change, gas production, and formation of a precipitate.

Front

What is a precipitate?

Back

A solid that forms and settles out of a liquid mixture during a chemical reaction.

Front

What does the law of conservation of mass state?

Back

In a chemical reaction, the total mass of the reactants equals the total mass of the products.

Front

What is an exothermic reaction?

Back

A chemical reaction that releases heat, causing the temperature of the surroundings to increase.

Front

What is an endothermic reaction?

Back

A chemical reaction that absorbs heat, causing the temperature of the surroundings to decrease.

Front

What is the role of a catalyst in a chemical reaction?

Back

A catalyst speeds up a chemical reaction without being consumed in the process.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances.

Front

What is the balanced equation for the reaction between sodium and chlorine?

Back

2Na + Cl2 -> 2NaCl.

Front

What is the significance of balancing chemical equations?

Back

Balancing chemical equations ensures that the law of conservation of mass is obeyed, with equal numbers of each type of atom on both sides.