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

The Correct Option is A

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