How many carbon dioxide molecules are in 4.5 mol of CO2?

• 2.7 x 10^23

• 2.7 x 10^24

• 4.5 x 10^23

• 6.02 x 10^23

If there are 2.7 x 10^24 molecules of CO2, calculate the number of oxygen atoms.

• 5.4 x 10^23

• 5.4 x 10^24

• 2.7 x 10^24

• 6.02 x 10^23

There are 1.5 x 10^24 molecules of CO2 in a cube of dry ice. Calculate the amount, in mol, of dry ice.

• 1.5 mol

• 2.5 mol

• 3.5 mol

• 4.5 mol

Calculate the molar mass of CO2

• 12.011 g/mol

• 15.999 g/mol

• 28.01 g/mol

• 44.01 g/mol

How many moles of H2O in a 45.0g sample?

• 45 mol

• 18.02 mol

• 2.497 mol

• 0.4 mol

What is the mass of NaOH in 0.500 mol

• 20.0 g

• 0.500 g

• 40.00 g

• 1.0 g

Determine the percentage of carbon by mass in ethanol, CH3CH2OH

• 12.01%

• 24.02%

• 46.08%

• 52.13%

A compound contains 40.00% carbon, 6.70% hydrogen and 53.30% oxygen by mass. Determine the empirical formula of the compound.

• CHO

• CH2O

• C2HO3

• CHO2

The empirical formula of a compound is CH2 and the molar mass is 28.054g/mol. Determine the molecular formula of the compound.

• CH2

• C2H4

• C2H2

• C3H6

Ethanol burns with oxygen to form carbon dioxide and water vapour according to the balanced equation:

CH3CH2OH (l) + 3O2 (g) -> 2CO2 (g) + 3H2O (g)

Calculate the mass of carbon dioxide produced when 5.00g of ethanol is burnt.

• 46.08 g

• 0.1085 g

• 0.2170 g

• 9.55 g