8.0 g of an element X react with an excess of copper (ll) tetraoxosulphate (lV) solution to deposit 21.3 g of copper. The correct equation for the reaction is?
(Cu = 64).
- A. X(s) + CuSO4(aq) → Cu(s) + XSO4(aq)
- B. X(s) + 2CuSO4(aq) → 2Cu(s) + X(SO4)2(aq)
- C. 2X(s) + CuSO4(aq) → Cu(s) + X2SO4(aq)
- D. 2X(s) + 3CuSO4(aq) → 3Cu(s) + X2(SO4)3(aq)
A given amount of gas occupies 10.0 dm3 at 4atm and 273°C. The number of moles of the gas present is?
(Molar volume of a gas at s.t.p. = 22.4 dm3)
- A. 0.89 mol
- B. 1.90 mol
- C. 3.80 mol
- D. 5.70 mol
A mixture of iron and sulphur can be separated by dissolving the mixture in?
- A. steam
- B. dilute hydrochloric acid
- C. dilute sodium hydroxide
- D. benzene
The addition of water to calcium oxide leads to?
- A. a physical change
- B. a chemical change
- C. the formation of a mixture
- D. an endothermic change
(1 /(2) N2(g) + (1) / (2)O2(g) → NO(g) ∆H° 89 KJ mol–. If the entropy change for the reaction above at 25°C is 11.8 J mol–, calculate the change in free energy. ∆G°, for the reaction at 25°C?
- A. 88.71 KJ
- B. 85.48 KJ
- C. -204.00 KJ
- D. -3427.40 KJ
25 cm3 of 0.02 M KOH neutralized 0.03 g of a monobasic organic acid having the general formula CnH2n + 1 COOH. The molecular formula of the acid is?
(C = 12, H = 1, O = 16)
- A. HCOOH
- B. C2H5COOH
- C. CH3COOH
- D. C3H7COOH
The synthetic detergents are preferred to soap for laundry using hard water because?
- A. detergents are water soluble while soap is not
- B. the calcium salts of detergents are water soluble
- C. the magnesium salt of soap is soluble in hard water
- D. soap does not have a hydrocarbon terminal chain
Synthetic rubber obtained by the polymerization of chlorobutadiene in the presence of sodium is called?
- A. teflon
- B. isoprene
- C. polythene
- D. neoprene
The final product of the reaction of ethyne with hydrogen iodine is?
- A. CH3—CHI2
- B. CH2l—CH2I
- C. CH3—CI3
- D. CH2 = CHI
The reaction of an alkanol with an alkanoic acid in the presence of concentrated H2SO4 will produce an?
- A. alkanal
- B. alkanoate
- C. alkanone
- D. alkyne
An undesirable paraffin in the petroleum industry which is particularly prone to knocking is?
- A. iso-octane
- B. n-heptane
- C. iso-heptane
- D. n-octane
A sample of a substance containing only C and H burns in excess O2 to yield 4.4g of CO2
and 2.7 g of H2O. The empirical formula of a substance is?
(C = 12, O = 16, H = 1)
- A. CH3
- B. CH2
- C. CH4
- D. C2H24
Sodium hydroxide is prepared commercially from sodium chloride solution by?
- A. electrolysis using mercury as cathode
- B. hydrolysis in steam using a catalyst
- C. electrolysis using iron as anode
- D. treating sodium chloride with ammonia and carbon (IV) oxide
Which of the additives could improve the quality of steel?
- A. Silicon
- B. Sulphur and phosphorus
- C. Carbon
- D. Chromium and nickel
The removal of rust from iron by treatment with tetraoxosulphate (IV) acid is based on the?
- A. hydrolysis of the iron
- B. reaction of acid with base
- C. oxidationof the rust
- D. dehydration of the iron
2X(aq) + MnO2(s) + 4H+(aq) → X2(g) + Mn2+(aq) + 2H2O.
The reaction above can be used for the laboratory preparation of all halogens except fluorine because it is?
- A. a poisionous gas
- B. an oxidizing agent
- C. electronegative in nature
- D. highly reactive
Coal gas is made up of carbon (II) oxide, hydrogen and?
- A. nitrogen
- B. air
- C. argon
- D. methane
A compound that will NOT produce oxygen on heating is?
- A. potasium dioxonitrate (III)
- B. lead (IV) oxide
- C. potassium trioxochlorate (V)
- D. potassium trioxonitrate (V)
mE + nF → pG + qH. In the equation above, the equilibrium constant is given by?
- A. (E)m(F)n/ (G)n(H)q
- B. (E)(F) / (G)(H)
- C. (G)p(H)q / (E)m(F)n
- D. (G)(H) / (E)(F)
Oxidation of concentrated hydrochloric acid with manganese (IV) oxide liberates a gas used in the?
- A. manufacture of tooth pastes
- B. treatment of simple golitre
- C. vulcanization of rubber
- D. sterilization of water
One method of driving the position of equilibrium of an endothermic reaction forward is to?
- A. increase temperature at constant pressure
- B. dcrease pressure at constant temperature
- C. cool down the apparatus with water
- D. decreases temperature at constant pressure