a. A compound contains 52.2% C, 13.1 % H and Oxygen only. The vapour density of the compound is 23.
Determine i. its empirical formula; ii. its molecular formula, [H=1.0, C=12.0, O= 16.0]
iii1). The compound reacts with sodium metal to produce hydrogen gas and when warmed with acidified \(KMnO_{4(aq)}\) gives a solution that turns from purple to colorless. It also forms a sweet-smelling liquid when heated with ethanoic acid in the presence of concentrated \(H_2SO_4\)
name the functional group present in the compound; iii2). draw the structural formula of the compound.
b. Outline the chemical equations for the production of ethanol from cooked cassava.
ci. Explain briefly why a piece of aluminum does not react with water.
ii. How can a pure sample of aluminum chloride crystals be prepared from aluminium
d. Describe how water can be separated from aqueous \(CuSO_4\)
Explanation
ai. %0 = 100 - (52.2+13.1)
=34.7
C H O
52.2/12, 13.1/1, 34.7/16
4.35, 13.1, 2.168
4.35/2.168, 13.1/2.168, 2.168/2.168
2.00, 6.04, 1
empirical formula = \(C_2H_6O\)
ii. 2 x vapour density = molecular mass
2x23=46
(\(C_2H_6O)_n\) = 46
[(12 x 2) + (1 x 6) + 16]n = 46
46n = 46
n = 1
molecular formula = \(C_2H_6O\)
iii1. Hydroxyl
iii2. 
b. 2(\(C_6H_{10}O_5)_n + nH_2O --diatase→ nC_{12}H_{22}O_{11}\)
\(C_{12}H_{22}O_{11} + H_2O --maltase→ C_6H_{12}O_6 + C_6H_{12}O_6\)
\(C_6H_{12}O_6 --zymase→ 2C_2H_5OH + 2CO_2\)
ci. The reaction starts but the metal produces a layer of an oxide/aluminum oxide layer on its surface which is impermeable(to water) and stops the reaction.
ii. Add dilute hydrochloric acid to excess aluminum filter off the excess metal leave the filtrate in a warm place/evaporate the filtrate to the point of crystallization/leave it in the sun.
d. The flask is connected to the condenser and the solution is heated. The water vaporizes and is converted to(liquid)water in the condenser.