Chemistry Past Questions And Answers
which of the following elements has the highest ionization energy?
- A. Calcium
- B. Chlorine
- C. Flourine
- D. Magnesium
Which of the following pairs of salts undergo hydrolysis?
- A. AlCI3 and NH4CI
- B. AICI3 and NaCI
- C. FeCI3 and KCI
- D. Na2SO4 and K2 SO4
What is the percentage by mass of oxygen in Al2(SO4)3. 2H2O? [Al = 27, S = 32, H = 1, O = 16]
- A. 14.29%
- B. 25.39%
- C. 50.79%
- D. 59.25%
The bond between NH3 and H+ in NH4+ is?
- A. dative
- B. covalent
- C. hydrogen
- D. electrovalent
Electrolysis is applied in the following processes except
- A. electroplating
- B. extraction of aluminium
- C. extraction of iron
- D. purification of copper
When CaC2 reacts with water, the organic product forms is
- A) ethanol
- B) ethanoic acid
- C) ethane
- D) ethyne
1. (a )Define the term compound.
(b) Statetwo conditions necessary for the cracking of petroleum fractions.
(c)Name two transition elements that are used as catalyst.
(d) (i) Write an equation for the reaction between zinc dust and trioxonitrate (V) solution.
(ii) Which of the reactants in 1(d)(i) is:
I. reduced;
II. oxidized.
(e)Two isotopes of oxygen 16O and 18O have relative abundance of 90 % and 10 % respectively. Calculate the relative atomic mass of oxygen.
(f) List two ores of iron.
(g) (i) What is biotechnology?
(ii) Name one product that can be obtained using biotechnology.
(h) Define the term element.
(i) Statetwo sources of methane in the atmosphere.
(j) Explain briefly why the trend of the boiling points for group VII elements is in the order I\(_2\) > Brl\(_2\)> Cl\(_2\).
View Discussion (0)WAEC 2018 THEORYWhich of the following fraction is used as raw material for the cracking process?
- A) kerosine
- B) lubricating oil
- C) bitumen
- D) diesel oils
The electronic configuration of Mg 2+ is
- A) ls 22s 22P 63s23P2
- B) Is22s22P6
- C) ls22s22p63s2
- D) ls22s22P4
When 250 cm3 of a saturated solution of CuSO4 at 30°C was evaporated to dryness, 5.0 g of the salt was obtained.. What is the solubility of the salt at 30°C? [CuSO4 = 160]
- A. 0.031
- B. 0.125
- C. 0.640
- D. 1.560