Answer to Question #111715 in General Chemistry for Daniel

Question

How many hydrogen atoms are in 0.750 cm 3 of C3H8 gas at SATP?

Answer 1

SATP is at 25 degrees C (298.15 K) and 101 kPa. At these conditions, the volume of 1 mol of a gas is 24.4651 liters.

n = V/Vm

V = 0.750 cm³ = 0.750 mL = 0.00075 L

n = 0.00075 / 24.4651 = 3,0656x10^-5 mol

N = n * N_A = 3,0656x10^-5 * 6.022x10²³

N = 1,846x10¹⁹ - molecules of C3H8

N = 8 * 1,846x10¹⁹ = 1,48x10²⁰ - atoms of H