U6 Review

Front

What is the percent by mass of oxygen in MgO?

Back

40%

Front

How many grams of Fe2O3 are formed when 16.7 g of Fe reacts with excess oxygen? (Balanced equation: 4Fe + 3O2 -> 2Fe2O3)

Back

23.9 g

Front

How many molecules are in 3.6 grams of sodium chloride (NaCl)? (Molar mass of NaCl = 58.44 g/mol)

Back

3.7 x 10^22 molecules

Front

What is the percent by mass of oxygen in NO? (Molar mass of NO = 30 g/mol)

Back

53%

Front

What is the molar mass of C2H4O2? (C: 12 g/mol, H: 1 g/mol, O: 16 g/mol)

Back

60 g/mol

Front

Define molar mass.

Back

The mass of one mole of a substance, typically expressed in grams per mole (g/mol).

Front

What is the formula to calculate percent by mass?

Back

(Mass of component / Total mass) x 100%.

Front

What is the balanced equation for the formation of iron (III) oxide from iron and oxygen?

Back

4Fe + 3O2 -> 2Fe2O3.

Front

How do you convert grams to moles?

Back

Moles = Mass (g) / Molar mass (g/mol).

Front

What is Avogadro's number?

Back

6.022 x 10^23, the number of particles in one mole of a substance.