Answer:
a. 0.119mol Kr
Step-by-step 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