Question

What is the quantity of sugar charcoal obtained when 34.2 g sugar is charred using required quantity of conc. sulphuric acid under ideal conditions?

• A. 14.4 g
• B. 11.0 g
• C. 114 g
• D. 10.5 g

Answer 1

Answer: (A)

14.4 g

Answer 2

When sugar (sucrose) is charred using concentrated sulfuric acid, it undergoes dehydration and forms carbon (charcoal) and water. The balanced chemical equation for this reaction is:
C12H22O11 (sugar) $\rightarrow$12C (charcoal) + 11H2O (water)
According to the equation, 1 mole of sugar (342 g) produces 12 moles of carbon (charcoal) and 11 moles of water.To find the quantity of charcoal obtained when 34.2 g of sugar is charred, Calculate the number of moles of sugar:
Moles of sugar = $\frac {Mass \ of \ sugar}{Molar \ mass\ of \ sugar }$
Moles of sugar = $\frac {34.2 g}{42 \ g/mol}$
Moles of sugar = 0.1 mol
Since the molar ratio between sugar and charcoal is 1:12, we can determine the number of moles of charcoal produced:
Moles of charcoal = Moles of sugar x $\frac {12 \ moles \ of \ charcoal}{1 \ mole \ of\ sugar) }$
Moles of charcoal = 0.1 mol x 12
Moles of charcoal = 1.2 mol
Calculate the mass of charcoal obtained:
Mass of charcoal = Moles of charcoal x Molar mass of charcoal
Mass of charcoal = 1.2 mol x 12 g/mol
Mass of charcoal = 14.4 g
Therefore, when 34.2 g of sugar is charred, the quantity of charcoal obtained is 14.4 g