Unit 6 Flashcard Review

Front

What is the gram-formula mass of H2O?

Back

18 g/mol

Front

What is the percent composition of sulfur in MgSO4 (gram formula mass = 120 g/mol)?

Back

27%

Front

Calculate the molar mass (GFM) for Al(OH)3.

Back

78.0 g/mol

Front

What is the molecular formula if the empirical formula is CH2O and the molecular molar mass is 180.18?

Back

C6H12O6

Front

What is the empirical formula for N2S3?

Back

It is an empirical formula.

Front

Define gram-formula mass (GFM).

Back

The sum of the atomic masses of all atoms in a formula unit of a compound, expressed in grams per mole.

Front

How do you calculate percent composition of an element in a compound?

Back

(Mass of element in 1 mole of compound / Molar mass of compound) x 100%.

Front

What is an empirical formula?

Back

The simplest whole-number ratio of atoms of each element in a compound.

Front

What is the difference between empirical and molecular formulas?

Back

Empirical formula shows the simplest ratio of elements, while molecular formula shows the actual number of atoms in a molecule.

Front

How do you determine the molar mass of a compound?

Back

Add the atomic masses of all the elements in the compound's formula.