Moles & Molecular Mass

The relative atomic mass is the average mass of an atom compared to 

• the mass of a carbon-12 atom.
• 1/12 the mass of a carbon-12 atom
• the mass of a hydrogen atom
• 1/12 the mass of a hydrogen atom

The relative molecular mass of a compound is equal to the sum of its

• Atomic mass
• Atomic number
• Oxidation number
• Valence electrons

The formula of a compound is M(OH)₂. Given that the M_r of the compound is 98, calculate the A_r of M.

• 32
• 64
• 81
• 94

What is the mass of sodium hydroxide if the concentration of the same is 1.5 mol? (Ar: Sodium - 23, Hydrogen - 1, Oxygen - 16)

• 90 grams

• 40 kilograms

• 60 grams

• 65 grams

How many moles of carbon dioxide (CO2) are in 50 g of CO2? (Oxygen - 16, Carbon - 12)

• 1.7 mol

• 2.08 mol

• 1.14 mol

• 2.28 mol

The formula for the conversion of grams to molecules is:

( Use Mr for Molecular Mass)

(M for Mass)

(a)  

How many moles are in 15 grams of lithium? (molar mass of lithium is 6.94 g/mole)

• 2.2

• 2.2 mol

• 1.2 mol

• 2.8 mol

How many grams are in 2.4 moles of sulfur? (molar mass of sulfur is 32.07 g/ mole)

• 77 g

• 74 g

• 75 g

• 82 g

Determine the number of moles of AlNO₃ that are in 264 g of the compound.

• 2.97 mol

• 3.45 mol

• 2.73 mol

• 1.86 mol

Find the mass of 5.82 mol of MgCl₂. Round to the nearest tenth.

• 552.9 g

• 436.8 g

• 55.2 g

• 555.9 g