Which element contains the greatest number of moles?
- A. 8 g of Helium
- B. 48 g of Carbon
- C. 78 g of Potassium
- D. 130g of Zinc
- E. 216g of Sliver
The use of sulphur to vulcanize rubber is made to make it
- A. blacker.
- B. cheaper. .
- C. more elastic
- D. tougher
- E. softer.
The atomic number of iron is 56. The number of unpaired electrons in the Fe3+ ion is
- A. 1
- B. 2
- C. 3
- D. 4
- E. 5
Animal charcoal differs from wood charcoal in that it
- A. has a dark colour
- B. has a high carbon content
- C. is a good absorbent
- D. is crystalline.
- E. is rich in phosphate content
Which statement BEST describes the process of oxidation?
- A. addition of hydrogen
- B. loss of oxygen
- C. decrease in oxidation number
- D. loss of electrons
- E. gain of elections.
The decreasing order of the oxidising power of the halogens is
- A. Br>I>Cl>F
- B. F>I>Cl>Br
- C. F>Cl>Br>l
- D. I>Br>Cl>F
- E. Cl>Br>F>I
20 cm3 of 0.09 mol dm3 solution of tetraoxosuiphate (Vi) acid requires 30cm3 of sodium hydroxide solution for complete neutralization. The molar concentration of sodium hydroxide is [H = 1; S = 32; 0 = 16; Na = 23]
- A. 0.03 mol dm3
- B. 0.12 mol dm3
- C. 0.27 mol dm3
- D. 0.45 mol dm3
- E. 0.90 mol dm3
When steam is passed over red hot carbon the substances produced are
- A. hydrogen and trioxocarbonate (IV) acid
- B. hydrogen, oxygen and carbon (IV) oxide
- C. hydrogen and carbon (ii) oxide
- D. hydrogen and carbon (IV) oxide
Calculate the relative molecular mass of Limestone CaCO3, (Ca = 40, C =12, O = 16)
- A. 56
- B. 100
- C. 76
- D. 90
In the electrolysis of brine the anode is
- A. platinum
- B. copper
- C. zinc
- D. carbon
The oxidation state of sulphur on H2SO4 acid is
- A. -4
- B. +6
- C. 4
- D. -8
S block elements of the periodic table one made up of
- A. groups 1, 2, 3
- B. groups 1, and 2
- C. group 3
- D. group 3 to 7
In the electrolysis of CuSo4(g) using platinum electrode the reaction at the anode is
- A. 4H+ 4e - 2H2
- B. 4OH= 4e- + 2H2O + O2
- C. 2OH - 2e- = 2OH
- D. 2OH- + 2OH = 2H2O + O2
The principal constituent of natural gas is
- A. methane
- B. ethane
- C. propane
- D. Butane
Chlorine consisting of two isotope of mass number 35 and 37 in the ratio 3:1 has an atomic mass of 35.5. Calculate the relative abundance of the isotope of mass number 37
- A. 20
- B. 25
- C. 60
- D. 75
Chlorine gas turns damp starch-iodide paper
- A. pink
- B. colourless
- C. red
- D. dark blue
N2O4(g)→ 2NO2(g)
In the endothermic reaction above, more products formed will be favored by
- A. A constant values
- B. an increase in pressure
- C. a decrease pressure
- D. a decrease volume
what is the pH of 0.00lmoldm3 solution of sodium hydroxide
- A. 14
- B. 13
- C. 12
- D. 11
Which of the following compounds can be represented by the molecular formula C2 H6O?
- A. propanal
- B. ethanol
- C. methanoic acid
- D. glucose
If glucose is heated with concentrated tetraoxosulphate(vi)acid, it will be dehydrated to?
- A. carbon
- B. carbon(iv)oxide
- C. ethane
- D. ethanol
The substance that is used in the steel industry for the removal of carbon. Sulphur and phosphorus impurities from pig iron is
- A. oxygen
- B. chlorine
- C. nitrogen
- D. hydrogen