Chemical Reactions

The product of bubbles is a sign that

• a chemical change is taking place
• a physical change is taking place
• oxygen is present
• organic chemicals are present

A decomposition reaction is a reaction between at least two reactants in which

• one breaks down into at least two products.
• a compound is decomposed by an electric current.
• a compound burns in the presence of oxygen.
• a new, more complex compound is formed.

A chemical equation is balanced by changing or adding

• chemical symbols.
• subscripts
• coefficients.
• reactants.

An example of an endothermic reaction is:

• refining aluminum ore.
• activating an instant cold pack.
• heating “meals-ready-to-eat” (MREs) by pouring water into the ration heater.
• changing water to steam

A chemical reaction in which the energy is absorbed primarily in the form of heat is ______.

• flammable
• exothermic
• endothermic
• endergonic

A substance that speeds up a chemical reaction without undergoing permanent change itself is a(n) 

• inhibitor
• coefficient
• reactant
• catalyst

The breaking down of a substance into two or more substances is ______________.

• synthesis
• decomposition
• single-displacement
• double-displacement

If energy in the form of heat is given off when a chemical reaction takes place, the reaction is 

• exothermic
• exerrgonic
• cooled
• endothermic

What type of chemical reaction is shown in the equation AgNO₃ + KCl     〉 AgCl + KNO₃?

• synthesis
• decomposition
• single-displacement
• double-displacement

A _________ chemical equation has the same number of atoms of each element on both sides of the equation.

• simple
• balanced
• unbalanced
• complex