43
A concentrated solution containing H+, Cu2+, OH- and Cl- was electrolyzed using platinum electrodes.
The ion that will be discharged at the cathode is?
- A. Cu2+
- B. Cl-
- C. H+
- D. OH-
44
2H2 + O22 โ H2+O ฮH = -571kJ
In the equation above, how much heat will be liberated if 12.0g of hydrogen is burnt in excess oxygen?
- A. -1142 kJ
- B. -571 kJ
- C. +1142 kJ
- D. -1713 kJ
45
In which of the following reactions can the oxidation number of the nitrogen be said to have increased?
- A. 2NO(g) + O2(g) โ 2NO2(g)
- B. 2NO(g) + Cl2(g) โ 2NOCl(l)
- C. FeSO4(aq) + NO(g) โ Fe(NO)SO4(s)
- D. NO(g) + Br2(l) โ 2NOBr(l)
46
When iron is exposed to moisture and it rusts, the value of ฮG for the reaction is
- A. neutral
- B. zero
- C. positive
- D. negative
47
Phenolphthalein in acidic solution is
- A. red
- B. orange
- C. colourless
- D. yellow
48
Which of the following ions require the largest quantity of electricity for discharge at an electrode?
- A. 4.0 moles of Cl-
- B. 3.0 moles of Na+
- C. 2.5 moles of Cu2+
- D. 2.0 moles of Al3+
49
Which of the following equimolar solutions will have the highest pH?
- A. CH3COOHa
- B. NaOH
- C. HCl
- D. NH4OH