UNN Chemistry 2008/2009 Past Questions

What are the values of p, q , r and s respectively in the equation?
pCH₄ + qO₂ -----> sCO + sH₂O

KHCO₃ is contaminated with K₂CO₃ as impurity. If 2.5g of the impure KHCO₃ on heating produces 0.224dm³ of CO₂ at s.t.p., calculate the percentage of K₂CO₃ impurity
(K = 39, H = 1, C = 12, O = 16)

The partial pressure of N₂ in a container at 50°C in which there are 0.30 mole of N₂ and 1.2 mole of CO₂ at a pressure of 2.00 atm is?

The major reason why chemical reaction occurs among elements is that they have the tendency to

Given that the pH of a solution of KOH is 12, what is the concentration of the OH ions?

Which of the following salt has a pH less than 7?

In which of the following reactions does hydrogen peroxide act as reducing agent?

Temporary hardness of water is removed by the use of the following EXCEPT

Hydration of ions in addition is associated with

A piece of radioactive element has initially 8.0 x 10²³ atoms. Half life is two days. After 16 days, the number of atoms is

Which of the following pairs of substances are hygroscopic?

Zinc is not regarded as a transition metal even though it is a d-block element because

Silver chloride turns grey when exposed to sunlight because

Which of these compounds exhibits resonance?

Hydrolysis of CH₃COOCH₂CH₃ in dilute HCl produces