OAU Chemistry 2021/2022 Past Questions

Practice each question, then open it to see the full details.

Soaps and detergents have the same basic characteristics except that the carboxyl group of the fatty acid in detergent is replaced by:

A.alcohol
B.sulphate or a sulphonate group
C.ester
D.acids

Solid carbon dioxide (dry ice) is used as refrigeration agent because it readily changes directly from solid to gas at a low temperature. This shows that the main intermolecular bonding in carbon dioxide is:

A.hydrogen bonding
B.covelent bonding
C.ionic bonding
D.London forces

The bond in ammonium chloride molecule is

A.ionic only
B.covalent only
C.ionic and dative covalent
D.dative covalent only
E.none of the above

300cm³ of a gas has a pressure of 800mmHg. If the pressure is reduced to 650 mmHg, find its volume.

A.243.75cm³
B.369.23cm³
C.738.46cm³
D.1733.36cm³

P_(g) + G_(g) <--->3R_(s) + S_(g), ∆H is negative. Which of the following will increase the yield of R?

A.Using a larger closed vessel
B.Increasing the temperature
C.Removing some S
D.Adding a positive catalyst.

Compounds that have the same molecule formula but different structures are said to be

A.allotropic
B.isotopic
C.polymeric
D.isomeric

Calculate the mass of ZnSO₄ produced when excess ZnCO₃ is added to 50.00cm³ of 4.00 H₂So₄. The equation for the reaction is: ZnCo₃ + H₂SO₄ → ZnSO₄ + CO₂ + H₂O [ZnSO₄ = 161g/mol]

A.0.200g
B.32.2g
C.1.29g
D.39.0g