Answer to Question #300782 in General Chemistry for stizzard

Question

1.   In an experiment, 112cm³ of carbon (iv) oxide gas were collected at s.t.p. How many molecules of the gas are present? (molar volume of the gas at stp=22.4dm, L=6.02 x 10²³mol^-1)

Answer 1

Convert $112cm^3$ of $CO_2$ to $dm^3=112\times 0.001=0.112dm^3$

Molar volume of the gas at stp= $22.4dm^3=6.02\times 10^{23}mol^{-1}$

Molecules of $0.112dm^3$ of carbon (iv) oxide $=0.112/22.4 \times 6.02 \times10^{23=3.01\times 10^21} molecules$