Chemistry Basics: Moles and Equations

Front

What is a mole in chemistry?

Back

A mole is a unit of measurement used to express the amount of a substance. It is defined as the amount of substance that contains as many entities (atoms, molecules, etc.) as there are in 12 grams of carbon-12.

Front

What is the molar mass of an element?

Back

The molar mass of an element is the mass of one mole of that element, typically expressed in grams per mole (g/mol). It is numerically equal to the atomic mass of the element.

Front

How do you calculate the number of moles from grams?

Back

Number of moles = mass (g) / molar mass (g/mol).

Front

What is the balanced equation for the reaction of silver and oxygen to form silver oxide?

Back

4Ag + O2 -> 2Ag2O.

Front

How many moles are in 24 grams of magnesium (Mg)?

Back

1 mole (since the molar mass of Mg is 24 g/mol).

Front

What is the stoichiometric coefficient in a balanced chemical equation?

Back

The stoichiometric coefficient is a number that represents the ratio of moles of each substance involved in a chemical reaction.

Front

How do you determine the limiting reactant in a chemical reaction?

Back

The limiting reactant is the substance that is completely consumed first in a chemical reaction, limiting the amount of product formed.

Front

What is the molar mass of copper (Cu)?

Back

The molar mass of copper is 63.5 g/mol.

Front

How many grams are in 0.5 moles of copper?

Back

31.75 grams (0.5 moles x 63.5 g/mol).

Front

What is the balanced equation for the reaction of carbon monoxide and hydrogen to form methane and water?

Back

CO + 3H2 -> CH4 + H2O.