Question

Radon is a radioactive noble gas that can sometimes be found in unventilated basements. A sample of 1.35×10−4mol of radon gas is held in a container with a volume of 3.03mL. A quantity of radon gas is added to the container, which is then found to have a volume of 7.79mL at the same temperature and pressure. How many moles of radon were added to the container?

Answer 1

Answer: 2.12 X 10^-4

Step-by-step explanation:

First, find the final number of moles of radon in the container after the addition by rearranging Avogadro's law to solve for n2.

n2= V2 × n1 / V1

Substitute the known values ofn1, V1, and V2.

n2 = 7.79 mL × 1.35 × 10^−4 mol / 3.03 mL = 3.47 × 10^−4 mol

Find the difference between the final number of moles (n2) and the initial number of moles (n1).

n2−n1 = 3.47 × 10^-4 mol −1 .35 × 10^−4 mol= 2.12 × 10^−4mol

Answer 2

2.12*10^-4 moles

Step-by-step explanation:

If 3.03ml contains 1.35*10^-4mol then 7.79 will contain 7.79ml*1.35*10^-4/3.03= 3.47*10^-4 moles

Amount added= (3.47-1.35)*10^-4=2.12*10^-4moles