Snapquiz - Empirical Formula

Question 1. What is the A_r 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 2. What's the next step once you've found the mass in grams of an element in your compound and its A_r value?

Find the ratio of the mass to the A_rSubtract the A_r value from the mass.
Find the ratio of the A_r values to each other.
Divide the mass by the A_r value.

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

Question 4. If a compound has a 1:2 ratio of carbon atoms to oxygen atoms, what is its chemical formula?

CO₂.
CO.
OC₂.
C₂O.

Question 5. A carbon oxide is found to have a 1:1 ratio of carbon to oxygen. What is its correctly-written empirical formula?

CO
C₁O₁
CO₂
C₂O

If you would like to track your scores, please enter your preferred first name into the box (please note, this uses cookies to store the data on your computer/phone/tablet - please see the FAQ for more information). Alternatively, if your teacher has given you a code starting with a # symbol, you can enter that: