Chemical Equations study guide

The arrow in a chemical equation indicates which compounds have greater mass.Required to answer. Single

• true

• false

The combination of chemical symbols and numbers that represent a single unit of a substance is called

• subscript.

• coefficient.

• chemical formula.

• ratio.

Is the equation above balanced or not balanced? Required to answer. Single choice. (1 Point) balanced not balanced

Na2 + 3h2 = 2Nh3

• balanced

• not balanced

A chemical _________________ shows both the reactants and the products of a chemical reaction.Required to answer. Single choice. (1 Point) formula ratio equation molecule

• formula

• ratio

• equation

• molecule

A substance present at the beginning of a chemical reaction that is chemically changed by the reaction is called the ___.Required to answer. Single choice.

• reactant

• synthesis

• product

• temperature

At the end of a chemical reaction, what is the total mass of the reactants compared to the total mass of the products?

• Reactant mass is greater than the product mass.

• Product mass is greater than the reactant mass.

• Total masses are the same.

• The mass cannot be measured.

The number placed in front of a chemical formula to show how many molecules of the substance are represented is called ?

• subscript.

• coefficient.

• chemical formula.

• ratio.

How do you read the arrow in an equation? Required to answer. Single choice. (1 Point)

• goes

• equals

• reaction is happening.

• makes

How many atoms of hydrogen and how many atoms of oxygen are present in this formula?

2H2O

(1 Point)

• 2 hydrogen and 2 oxygen

• 2 hydrogen and 1 oxygen

• 4 hydrogen and 2 oxygen

• 4 hydrogen and 1 oxygen

How many atoms of each element are in the compound described by this chemical formula? Required to answer. Single choice.

(CH3)2 N

(1 Point)

• 2 atoms of carbon (C), 6 atoms of hydrogen (H), 1 atom of nitrogen (N)

• 1 atom of carbon (C), 3 atoms of hydrogen (H), 1 atom of nitrogen (N)

• 2 atoms of carbon (C), 3 atoms of hydrogen (H), 1 atom of nitrogen (N)

• 2 atoms of carbon (C), 6 atoms of hydrogen (H), 2 atoms of nitrogen (N)