The products of the thermal decomposition of ammonium trioxonitrate (V) are
- A. NO 2 and oxygen
- B. NH3 and oxygen
- C. nitrogen and water
- D. N2O and water
Bleaching powder, CaOCI2, H2O, deteriorates on exposure to air because
- A. it loses its water of crystallization
- B. atmospheric nitrogen displaces chlorine from it
- C. carbon (IV) oxide of the atmosphere displaceschlorine from it
- D. bleaching agents should be stored in solution
Which of the following reactions is (are) feasible?
I Br (1) + 2CI 2(aq) 2Br (aq) + CI 2(g)
ll 21 (aq) + Br 2(1) 2Br (aq) + 1 2(s)
lll 2F (aq) + CI 2(g) 2CI (aq) + F 2(g) IV 2F (aq) + Br 2(1) 2Br (aq) + F 2(g)
- A. l
- B. ll
- C. l and lll
- D. lll and lV
Gunpower is made from charcoal, sulphur and potassium trioxonitrate (V) The salt in the mixture performs the function of
- A. an oxidant
- B. a reductant
- C. a solvent
- D. a catalyst
Some products of destructive distillation of coal are?
- A. carbon (IV) oxide and ethanoic acid
- B. trioxocarbonate (IV) acid and methanoic acid
- C. producer gas and water gas
- D. coke and ammoniacal liquor
The catalyst used in the contact process for the manufacture of tetraoxosulphate (VI) acid is
- A. manganes (IV) oxide
- B. manganese (ll) tetraoxosulphate (VI)
- C. vanadium (V) oxide
- D. iron metal
Which of the following represents the balanced equation for the reaction of copper with concentrated trioxonitrate (V) acid?
- A. Cu (s) + 2HNO 3(aq) → Cu (NO 3) 2(aq) + H 2(g)
- B. Cu (s) + 4HNO 3(aq) → Cu (NO 3) 2(aq) + 2H 2O (1) + 2NO 2(g)
- C. 3Cu (s) + 8HNO3(aq) → 3Cu (NO3)2(aq) + 4H2O(1) + 2NO(g)
- D. 3Cu(s) + 4HNO3(aq) → 3Cu(NO 3) 2(aq) + 2H 2O (1) + 2NO (g)
The combustion of ethene, C 2H 4, is given by the equation C 2H 4 + 30 2 → 2CO2 + 2H2 O; ∆H = – 1428 KJ. If the molar heats of formation of water and carbon (IV) oxide are – 286 kJ and – 396 kJ respectively, calculate the molar heat of formation of ethene in KJ
- A. - 2792
- B. + 2792
- C. - 64
- D. + 64
An element, Z froms an anion whose formula is [Z(CN)6]y. If Z has an oxidation number of +2, what is the value of y?
- A. - 2
- B. - 3
- C. - 4
- D. - 5
What is discharged at the cathode during the electrolysis of copper (ll) tetraoxosulphate (VI) solution?
- A. Cu 2+ only
- B. H + only
- C. Cu 2+ and H
- D. Cu 2+ and SO 2-
The same current is passed for the same time through solutions of AgNO3 and CuSO4 connected in series. How much silver will be deposited if 1.0 g of copper is produced?
[Cu = 63.5, S = 32, O = 16, Ag = 108, N = 14]
- A. 1.7 g
- B. 3.4 g
- C. 6. 8 g
- D. 13. 6 g
An acid and its conjugate base
- A. can neutralise each other to form a salt
- B. differ only by a proton
- C. differ only by the opposite charges they carry
- D. are always neutral substances
The substance ZnO dissolves in sodium hydroxide solution and mineral acid solution to give soluble products in each case. ZnO is therefore referred to as
- A. an allotropic oxide
- B. an amphoteric oxide
- C. a peroxide
- D. a dioxide
A solution of calcium bromide contains 20 g dm 3 What is the molarity of the solution with respect to calcium bromide and bromide ions? [Ca = 40, Br = 80]
- A. 0. 1, 0 . 1
- B. 0. 1, 0. 2
- C. 0. 1, 0. 05
- D. 0.05, 0.1
Using 50 cm 3 of 1 M potassium hydroxide and 100cm 3 of 1 M tetraoxosulphate (VI) acid, calculate the respective volumes in cm 3 of base and acid that would be required to produce the maximum amount of potassium tetraoxosulphate (IV) [ = 39, S = 32, O = 16, H = 1]
- A. 50, 50
- B. 25, 50
- C. 50, 25
- D. 25, 25
A hydrated salt of formula MSO4.xH2 O CONTAINS 45.3% by mass of water of crystalisation. Calculate the value of x [M = 56, S = 32, O = 16, H = 1 ]
- A. 3
- B. 5
- C. 7
- D. 10
Calcium hydroxide is added in the treatment of town water supply to
- A. kill bacteria in the water
- B. facilitate coagulation of organic particles
- C. facilitate sedimentation
- D. improve the taste of the water
The gaseous pollutant sulphur (IV)oxide is most likely to be detected in fairly reasonable quantities in the area around a plant for the
- A. extraction of aluminium from bauxite
- B. production of margarine
- C. smelting of copper
- D. production of chlorine from brine
How many valence electrons are contained in the element represented 3115P?
- A. 3
- B. 5
- C. 15
- D. 31
Four elements P,Q, R and S have atomic numbers of 4, 10, 12 and 14 respectively . Which of these electrons is a noble gas?
- A. P
- B. Q
- C. R
- D. S
The atomic number of caesium is 55 and its atomic mass is 133. The nucleus of caesium atom therefore contains
- A. 78 protons and 55 elections
- B. 55 protons and 78 neutrons
- C. 55 neutrons 78 electrons
- D. 78 protons and 55 neutrons