Question

1.00g of carbon is combusted in a limited supply of pure oxygen. 0.50g of the carbon combusts
to form CO2 and 0.50 g of the carbon combusts to form CO.
The resultant mixture of CO2 and CO is passed through excess NaOH(aq) and the remaining gas
is then dried and collected.
What is the volume of the remaining gas? (All gas volumes are measured at 25°C and 1 atmosphere pressure.)

Answer 1

Answer on Question #60099, Chemistry / Inorganic Chemistry

1. 1.00g of carbon is combusted in a limited supply of pure oxygen. 0.50g of the carbon combusts to form CO₂ and 0.50 g of the carbon combusts to form CO. The resultant mixture of CO₂ and CO is passed through excess NaOH(aq) and the remaining gas is then dried and collected. What is the volume of the remaining gas? (All gas volumes are measured at 25°C and 1 atmosphere pressure.)

Solution:

$$\begin{array}{l} C + O_2 = CO_2 \\ 2C + O_2 = 2CO \\ \end{array}$$

If mixture of CO and CO₂ passed through a solution of NaOH:

$$\begin{array}{l} CO_2 + 2NaOH = Na_2CO_3 + H_2O \\ CO + NaOH \neq (\text{no reaction}) - \text{remaining gas}. \\ n(CO) = n(C) = \frac{m(C)}{M(C)} = \frac{0.5g}{12g/mol} = 0.0417 \text{ mol} \\ \end{array}$$

Find volume of CO at 25°C and 1 atmosphere pressure:

$$\begin{array}{l} PV = nRT \\ V = \frac{nRT}{P} \\ V = \frac{0.0417 \times 0.082 \times 298}{1} = 1.019L \\ \end{array}$$

Answer: the volume of the remaining gas 1.019L.