Front

What is stoichiometry?

Back

Stoichiometry is the branch of chemistry that deals with the calculation of reactants and products in chemical reactions based on the conservation of mass.

Front

What is the mole concept?

Back

The mole is a unit of measurement in chemistry that represents 6.022 x 10^23 particles (atoms, molecules, ions, etc.).

Front

How do you calculate moles from grams?

Back

Moles = mass (g) / molar mass (g/mol).

Front

What is an empirical formula?

Back

An empirical formula is the simplest whole-number ratio of atoms of each element in a compound.

Front

How do you determine the empirical formula from a molecular formula?

Back

Divide the subscripts in the molecular formula by their greatest common divisor.

Front

What is the balanced equation for the formation of ammonia from nitrogen and hydrogen?

Back

N2 + 3H2 → 2NH3.

Front

How many moles of H2 are needed to react with 2 moles of N2?

Back

6 moles of H2 are needed.

Front

What is the relationship between moles of reactants and products in a balanced equation?

Back

The coefficients in a balanced equation represent the ratio of moles of reactants to moles of products.

Front

How do you find the number of particles in a given mass of a substance?

Back

Number of particles = (mass in grams / molar mass) x Avogadro's number (6.022 x 10^23).

Front

What is the molar mass of Beryllium (Be)?

Back

The molar mass of Beryllium is approximately 9.01 g/mol.