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 17 - 2015 - Paper 1

From the fermentation of glucose, the balanced reaction is:

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

From this equation, one mole of glucose produces two moles of CO₂. Therefore, the moles of CO₂ produced is:

$\text{Moles of } CO_2 = 2 \times n_{glucose} = 2 \times 0.057 \approx 0.114 \text{ mol}$

To calculate the volume of carbon dioxide produced, we can use the Ideal Gas Law:

$PV = nRT$

Where:

• P = pressure in kPa = 100 kPa
• V = volume in liters
• n = number of moles of gas = 0.114 mol
• R = ideal gas constant = 8.314 J/(mol·K)
• T = temperature in Kelvin = 25°C + 273.15 = 298.15 K

Rearranging the Ideal Gas Law gives us:

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

Substituting the values in:

$V = \frac{0.114 \text{ mol} \times 8.314 \text{ J/(mol·K)} \times 298.15 \text{ K}}{100 \text{ kPa}}$

Calculating gives:

$V \approx 2.83 \text{ L}$