When 0.5 moles of an unknown alkane is completely burned, it produces 45 grams of water. Determine the number of isomers possible for this alkane.
- 1
- 2
- 3
- 5
📝 Detailed explanation
Moles of H₂O = 45 / 18 = 2.5 mol.1 mole of alkane produces 2.5 / 0.5 = 5 moles of H₂O.
Alkane formula CₙH₂ₙ₊₂ produces (n + 1) moles of H₂O.
n + 1 = 5, so n = 4.
The alkane is Butane (C₄H₁₀).
Isomers for C₄H₁₀ are n-butane and isobutane.
Wait, let's re-calculate. If n=5, it produces 6 moles of H₂O.
If n=4, it produces 5 moles. n=4 is correct.
There are 2 isomers for Butane.
If the answer is 3, the alkane must be Pentane (n=5).
Check: 0.5 mol Pentane produces 3 mol H₂O (54g).
Based on 45g H₂O, n=4. Isomers = 2.