Question

2. You have a 3.50 {~mol} sample of radon (Ra) gas. How many grams of radon gas do you have? (Do not include units in your answer or place your answer in scientific notationl)

Answer 1

777 g

Step-by-step explanation:

We can use stoichiometry to convert different units in chemistry.

Molar Mass

Before we can convert moles to grams, we need to understand molar mass. Molar mass is the mass of 1 mole of an element. So, the unit for molar mass is grams per mole. This value can be found on the periodic table. Molar mass is found by taking the average mass of an element. By looking at the periodic table we can see that the molar mass of radon is 222 g/mol.

Stoichiometry

Now that we know the molar mass, we can start to convert. To convert from moles to grams, we need to multiply the given value by the molar mass.

• 
  `\displaystyle(3.50 \rm moles)/(1) *(222\rm grams)/(1\rm mole)=777\rm grams`

This means that in 3.50 moles of radon, there are 777 grams. Since the given value has 3 significant figures, so should the answer.