Chemical Reations

What happens in a chemical reaction?

• Atoms are destroyed.

• Atoms are created.

• Atoms are heated and cooled

• Atoms are rearranged

In a balanced chemical equation, the mass of the reactants is equal to the

• atoms in a molecule

• atomic mass of the elements

• volume of the reactants

• mass of the products

The substance that is formed in a chemical reaction is called the

• polymer.

• reactant.

• radical.

• product.

A reaction in which the products contain more chemical energy than the reactants is

• exothermic

• electrical

• endothermic

• exergonic

A chemical equation is balanced by changing or adding

• chemical symbols

• subscripts

• coefficents

• reactants

A balanced chemical equation shows the proportions of reactants and products necessary for

• the reaction to occur

• matter to be conserved

• energy use to be minamized

• electrolysis to occur

A substance that undergoes a change in a chemical reaction is

• a product

• a chemical

• a reactant

• an enzyme

What is/are the product(s) in the following reaction?

2NH₃ --> N₂ + 3H₂

• NH₃

• N₂

• H₂

• both B and C

Which type of reaction is represented in the graph above?

• hypothermic

• exothermic

• endothermic

• hyperthermic

What coefficient is missing in C₂H₄ + (?)O₂ --> 2CO₂ + 2H₂O?

• 2

• 3

• 4

• 5