2. 
M (N₂) = 14*2 = 28 г/моль
n = 4,8/28 = 0,17 моль
N = 0,17 * 6,02*10²³ = 1,02 * 10²³ молекул
3. 
m = n*M
n = 2,24/22,4 = 0,1 моль
M (H₂S) = 1*2 + 32 = 34 г/моль
m = 0,1 * 34 = 3,4 г
4. V = n * Vm

n = 27*10²³/ 6,02*10²³ = 4,5 моль
V = 4,5 * 22,4 = 100,8 л