Chemistry Past Questions and Answers

50cm 3 of a saturated solution of potassium trioxonitrate (V)at 40°C contains 5.05g of the salt. What is the solubility of potassium trioxonitrate (V) at 40°C? (KNO3 = 101)

A 1.0 mol dm^-3
B 1.5 mol dm^-3
C 2.0 mol dm^-3
D 2.5mol dm^-3
E 5.0mol dm^-3

Question 87:

The oxidation number of chlorine is + 1 in

A KCIO ₃
B CI ₂O ₇
C ZnCI₂
D HCI
E NaCIO

Question 88:

What is the voltage of the cell represented at Zn_(s) Zn ²⁺_(aq) /Cu²⁺_(aq) /Cu_(s) given that for Cu ²⁺_(aq)/ Cu _(s) E_o = 0.337V and for Zn²⁺_(aq) /Zn_(s)' E _o = -0.763V?

A +0.426V
B -0.426V
C -0.337V
D -1.10V
E +1.10V

Question 89:

(a) Write the chemical equation for the formation of named alkanoate.
(b)(i) What are the monomers of protein called?
(ii) Write the two functional groups present in the monomers named in (b)(i) above
(iii) State the type of reaction that leads to the formation of proteins from their monomers.

Question 90:

(a) When is a sample of water said to be hard?
(b) State one difference between temporary and permanent hardness of water
(c) Give one method of removing hardness completely from water
(d) Name two local is used for the production of soap.