What mass of copper would be formed when a current of 10.0 A is passed through a solution of CuSO4 for 1 hour? [Cu = 63.5; 1F = 96500C]
- A. 5.9 g
- B. 11.8 g
- C. 23.8 g
- D. 47.3 g
What is the value of n in the following equation? Cr2O72- + 14H+ + ne– → 2Cr 3+ + 7H2O
- A. 2
- B. 3
- C. 6
- D. 7
Consider the following reaction equation:
X(g) + Y(g) ⇌ XY(g); ∆H = + 220KJ mol-1 If the temperature of the system is increased, the
- A. backward reaction would be favoured
- B. forward reaction would favoured
- C. reaction would stop
- D. reaction would be at equilibrium
On evaporation to dryness, 250 cm3 of saturated solution of salt X with relative molar mass 101 gave 50.5g of the. What is the soluility of the salt?
- A. 1.0 mol dm-3
- B. 2.0 mol dm-3
- C. 4.0 moldm-3
- D. 5.0 moldm-3
Which of the following metallic oxides is amphoteric?
- A. AI2O3
- B. Fe2O3
- C. MgO
- D. Na2O
When NH 4CI was dissolved in water, the container was cold to touch. This implies that
- A. the process is endothermic
- B. the process is exothermic
- C. NH4CI is highly soluble in water
- D. NH 4CI forms a saturated solution
Which of the following statements about enthalpy of neutralization is correct? It
- A. is constant for a strong acid and a strong base
- B. cannot be determined using calorimeter
- C. has a positive value
- D. is higher for strong acid and a weak base
The colour of phenolphthalein indicator in alkaline solution at the end-point of an acid-base titration is?
- A. colourless
- B. orange
- C. pink
- D. yellow
Which of the following equimolar solutions has the highest conductivity?
- A. CH3COOH(aq)
- B. H2CO3(aq)
- C. H 2SO 4(aq)
- D. NaOH (aq)
The initial volume of a gas at 300 K was 220 cm 3 Determine its temperature if the volume became 250 cm 3
- A. 183 K
- B. 264 K
- C. 300 K
- D. 341 K
The equation P = \(\frac{K}{V}\) illustrates
- A. Boyle's law
- B. Charles' law
- C. Dalton's law
- D. Gay Lussac's law
Bubbling excess carbon (IV) oxide into calcium hydroxide solution results in the formaton of
- A. CaO
- B. Ca(HCO3)2
- C. H2CO3
- D. CaCO3
A gas that is collected by upward delivery is likely to be
- A. heavier than air
- B. insoluble in water
- C. lighter than air
- D. soluble in water
Which of the following statements about a molar solution is correct? it
- A. is a supersaturated solution
- B. cannot dissolve more of the solute at that temperature
- C. contains any amount of solute in a given volume of solution
- D. contains one mole of the solute in 1 dm3 of solution
The number of atoms in one mole of a substance is equal to the
- A. mass number
- B. oxidation number
- C. atomic number
- D. avogadro number
What is the amount of magnesium that would contain 1.20 x 1024 particles? [Mg = 24, Avogadro’s constant = 6.02 x 1023]
- A. 0.5 moles
- B. 2.0 moles
- C. 12.0 moles
- D. 24.0 moles
Consider the reaction represented by the following equation: xKMnO 4(aq) + ySO2(g) + zH2O(I) → K 2SO4(AQ) + 2MnSO4(aq) + 2H2SO x,y and z are respectively
- A. 2,5 and 2
- B. 2,2 and 5
- C. 5, 1 and 2
- D. 1, 5 and 2
The volume occupied by 17g of H2S at s.t.p. is [H = 1.00, S = 32.0, Molar volume = 22.4 dm3]
- A. 11.2dm 3
- B. 17.0 dm3
- C. 34.0dm 3
- D. 44.8dm 3
Which of the following statements about displacement reaction is correct?
- A. A more electropositive element displaces a less electroposive one
- B. A less electropositive element displaces a more electropositive one
- C. The position of elements in the reactivity series has no effect on the reaction
- D. it only occurs when the reaction is at equilibrium
In metallic colids, the forces of attraction are between the mobile valence electrons and
- A. atoms
- B. neutrons
- C. the negative ions
- D. positively charged nuclei
When element 20A combines with element 8Y,
- A. a covalent compound, AY is formed
- B. an ionic compound AY is formed
- C. an ionic compound, A2Y is formed
- D. a covalent compound, AY2 is formed