# Snapquiz - Empirical Formula

This is the Snapquiz on Empirical Formula. Click here or use the embedded video if you haven't watched the lesson yet.

Question 1. Sulphur has an Ar value of 32 and oxygen has an Ar value of 16. A sulphur oxide contains 6.4g of sulphur and 6.4g of oxygen. What is the empirical formula of the sulphur oxide?

S2O2
S2O
SO2
SO

Question 2. If a compound has a 1:2 ratio of carbon atoms to oxygen atoms, what is its chemical formula?

OC2.
CO.
CO2.
C2O.

Question 3. How would you find the mass increase due to oxygen in the oxidation of magnesium?

Subtract the mass before oxidation from the mass after oxidation.
Subtract the mass after oxidation from the mass before oxidation.
Find the ratios of the masses before and after oxidation.
Add the masses before and after oxidation together.

Question 4. Which is the correct sequence of values to calculate to find the empirical formula?

Ratio, Ar values, Masses, Division.
Masses, Ar values, Division, Ratio.
Ar values, Division, Ratio, Masses.
Division, Masses, Ar values, Ratio.

Question 5. 89.2g of lead oxide is heated with carbon, which reduces it (removes its oxygen). Afterwards 82.8g of pure lead is left. How would we find the mass of oxygen lost?

Simplify the ratio 89.2 : 82.8
82.8g - 89.2g
89.2g - 82.8g
Divide both values by Ar values.