Stoichiometry grams to moles flashcards

What is a mole?

A mole is $\displaystyle 6.022 \times 10^{23}$ particles of a substance.

Molar mass definition

The mass of one mole of a substance, usually in g/mol.

Formula to convert grams to moles

Use: $\displaystyle \text{moles} = \frac{\text{grams}}{\text{molar mass}}$.

True or false: Molar mass is the same for all substances.

False, because molar mass varies by substance.

Difference between grams and moles

Grams measure mass; moles measure quantity of particles.

How to find molar mass?

Add the atomic masses of all atoms in a molecule.

What unit is molar mass measured in?

Molar mass is measured in grams per mole (g/mol).

Example: Molar mass of H₂O?

Molar mass = $\displaystyle 2\times1 + 16 = 18 \text{ g/mol}$.

How many moles in 50 g of NaCl?

Molar mass of NaCl = 58.44 g/mol, so $\displaystyle \frac{50}{58.44} \approx 0.855$ moles.

Fill in the blank: 1 mole of carbon has a mass of ___ g.

12.01 g (molar mass of carbon).

What does the term stoichiometry mean?

The calculation of reactants and products in chemical reactions.

True or false: 1 mole of any gas occupies the same volume.

True, because at STP, 1 mole of any gas occupies 22.4 L.

How to convert moles to grams?

Use: $\displaystyle \text{grams} = \text{moles} \times \text{molar mass}$.

Question: What is the molar mass of CO₂?

Molar mass = $\displaystyle 12.01 + 2\times16 = 44.01 \text{ g/mol}$.

What is Avogadro's number?

Avogadro's number is $\displaystyle 6.022 \times 10^{23}$, representing particles in a mole.

Difference between empirical and molecular formula

Empirical shows simplest ratio; molecular shows actual number of atoms.

How many grams in 2 moles of H₂?

Molar mass of H₂ = 2.02 g/mol, so $\displaystyle 2 \times 2.02 = 4.04$ g.

What is the unit for measuring mass in stoichiometry?

Mass is measured in grams (g) in stoichiometry.