Question

Which of the following has a mass of 10.0 g?

Answer 1

Answer:

a.  0.119mol Kr

Explanation:

To solve this problem, we must understand that;

     Mass  = number of moles x molar mass

Molar mass of Kr  = 83.3g/mol

                        Ar = 40g/mol

                        He = 4g/mol

                        Ne = 20.18g/mol

a0.119 mol Kr               mass  = 0.119 x 83.3 = 9.9g

b 0.400 mol Ar             mass  = 0.4 x 40  = 16g

C 1.25 mol He               mass  = 1.25 x 4  = 5g

d 2.02 mol Ne              mass  = 2.02 x 20.18  = 40.8

Krypton is the answer