Moles Flashcard - APA

Front

What is the molar mass of glycerol?

Back

92.09 g/mol

Front

What is the molecular formula for glycerol based on its percent composition?

Back

C₃H₈O₃

Front

What is an empirical formula?

Back

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

Front

Which pair has the same empirical formula: NaCrO₄ and Na₂Cr₂O₇, or C₂H₄O₂ and C₆H₁₂O₆?

Back

C₂H₄O₂ and C₆H₁₂O₆.

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 the empirical formula for a compound with 72.2% magnesium and 27.8% nitrogen?

Back

Mg₃N₂.

Front

What is the percent composition of hydrogen in (NH₄)₂S?

Back

11.8%.

Front

What is the molecular formula for a compound with the empirical formula K₂SO₄ and a molecular mass of 696g?

Back

K₈S₄O₁₆.

Front

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

Back

Multiply the subscripts in the empirical formula by a whole number to match the molecular mass.

Front

What is the significance of percent composition in chemistry?

Back

It helps to understand the proportion of each element in a compound.