Chemistry Past Questions And Answers
An element \(^{226}_{88}X\) undergoes radioactive decay by emitting two alpha particles and a beta radiation. Which of the following nuclei correctly describe the product formed by the reaction?
- A) \(^{222}_{89}T\)
- B) \(^{218}_{84}S\)
- C) \(^{218}_{85}R\)
- D)\(^{227}_{87}Q\)
Which of the following metals exists as liquid at ordinary temperature?
- A. Copper
- B. Gold
- C. Mercury
- D. Silver
An element, Q, contains 69% of63Q and 31% of65Q. What is the relative atomic mass of Q?
- A. 63.0
- B. 63.6
- C. 65.0
- D. 69.0
The property which makes alcohol soluble in water is the
- A. boiling point
- B. hydrogen bonding
- C. ionic character
- D. covalent nature
Copper (II) ions are able to participate in co-ordinate covalent bonding because they
- A. are coloured
- B. are positively charged
- C. have vacant d-orbital
- D. have unpaired electrons
Producer gas is a mixture of
- A. oxygen and hydrogen
- B. Hydrogen and nitrogen
- C. nitrogen and oxygen
- D. nitrogen and carbon (ll) oxide
The bleaching action of chlorine gas is effective due to the presence of
- A) hydrogen chloride
- B) water
- C) air
- D) oxygen
Calculate the mass of sodium hydroxide in 5.00 dm3 of a 0.125 mol dm-3 solution. [NaOH = 40 g mol-1]
- A. 0.0156 g
- B. 0.625 g
- C. 1.00 g
- D. 25.0 g
Which or the following substances is a polypeptide?
- A. Starch
- B. Glycogen
- C. Protein
- D. Fats
A reaction is represented by the equation below. A2(g) + B2(g) 2AB(g); ∆H = +X kJmol-1 Which of the following statements about the system is correct?
- A. The reaction goes to completion at equilibrium
- B. The forward reaction is exthermic
- C. At equilibrium increase in temperature favours the reverse reaction
- D. Pressure has no effect on the equilibrium mixture