Unit Four Optional Review

Front

What is a stock solution?

Back

A highly concentrated solution that is meant to be diluted to some lower concentration.

Front

What is the abbreviation for molarity?

Back

M

Front

How do you determine the empirical formula from percent composition?

Back

Convert the percentages to grams, divide by the molar mass of each element, and find the simplest whole number ratio.

Front

What is the empirical formula for a compound with 88.80% copper and 11.20% oxygen?

Back

Cu2O

Front

How do you calculate the number of moles in a solution?

Back

Moles = Molarity (M) x Volume (L).

Front

What happens to the number of moles when a solution is diluted?

Back

The number of moles remains the same; only the concentration changes.

Front

If 0.775 L of 1.00 M NaOH is diluted to 1.00 L, how many moles of NaOH are present?

Back

0.775 mol NaOH.

Front

What is percent composition?

Back

The percentage by mass of each element in a compound.

Front

What is the percent composition of aluminum phosphate (AlPO4)?

Back

Al = 22.1%, P = 25.4%, O = 52.5%.

Front

How do you calculate percent composition from a chemical formula?

Back

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