What volume of carbon dioxide will be produced if 10.3 g of glucose is fermented at 25°C and 100 kPa? (A) 1.30 L (B) 1.42 L (C) 2.57 L (D) 2.83 L - HSC - SSCE Chemistry - Question 20 - 2015 - Paper 1

According to the fermentation of glucose, the balanced equation is:

$C_6H_{12}O_6 \rightarrow 2 CO_2 + 2 C_2H_5OH$

This indicates that 1 mole of glucose produces 2 moles of carbon dioxide. Hence, the moles of carbon dioxide produced will be:

$2 \times n_{glucose} = 2 \times 0.0571 \, \text{mol} \approx 0.1142 \, \text{mol CO}_2$

Next, we can calculate the volume of carbon dioxide at standard conditions using the ideal gas law:

$PV = nRT$

Where:

• $P$ = pressure (100 kPa)
• $V$ = volume (L)
• $n$ = number of moles of CO2
• $R$ = universal gas constant (8.314 kPa·L/(mol·K))
• $T$ = temperature (25°C = 298 K)

Rearranging for volume, we get:

$V = \frac{nRT}{P}$

Calculating this gives:

$V = \frac{0.1142 \, \text{mol} \times 8.314 \, \text{kPa·L/(mol·K)} \times 298 \, \text{K}}{100 \, \text{kPa}} \approx 2.83 \, \text{L}$