# 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?

S2O
SO2
S2O2
SO

Question 2. What is the Ar value of an element?

The number of neutrons in an atom.
The charge on an atom.
The proton number of an atom.
The mass number of an atom.

Question 3. 3.1g of phosphorus reacts with oxygen to make 7.1g of phosphorus oxide. What is the empirical formula of this oxide?

P1O2.5
P2O5
PO2.5
P2.5O

Question 4. Butene contains four carbon atoms and eight hydrogen atoms. What is its empirical formula (not its molecular formula)?

C4H8
CH2
C2H4
CH

Question 5. What's the next step once you've found the mass in grams of an element in your compound and its Ar value?

Find the ratio of the mass to the ArFind the ratio of the Ar values to each other.
Subtract the Ar value from the mass.
Divide the mass by the Ar value.