Units 3 & 4 CMT Review Adv

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

Which pair has the same empirical formula: NaCrO4 and Na2Cr2O7, C2H4O2 and C6H12O6, C3H6O3 and C2H6O2, CH4 and C2H6?

Back

C2H4O2 and C6H12O6 have the same empirical formula.

Front

How do you calculate percent composition of a compound?

Back

Percent composition is calculated by dividing the mass of each element in a compound by the total molar mass of the compound and multiplying by 100.

Front

Find the percent composition of N2S2.

Back

N: 30.4%, S: 69.6%.

Front

What is molarity?

Back

Molarity is a measure of concentration, defined as the number of moles of solute per liter of solution.

Front

If 50.0 mL of a 0.78 M solution is diluted to 90.0 mL, what is the ending molarity?

Back

The ending molarity is 0.43 M.

Front

What is the formula for calculating dilution?

Back

The formula is M1V1 = M2V2, where M is molarity and V is volume.

Front

What percentage of the total atomic mass of lithium phosphide (Li3P) is composed of lithium?

Back

40% of the total atomic mass is composed of lithium.

Front

What is the difference between molecular and empirical formulas?

Back

A molecular formula shows the actual number of atoms of each element in a molecule, while an empirical formula shows the simplest ratio of these atoms.

Front

Is Mg3O9 a molecular or empirical formula?

Back

Mg3O9 is a molecular formula.