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
In countries where the temperature fall below 273k, salt always spilled on the road in order to
- A. increase the boiling point
- B. increase the density of the ice
- C. make the ice impure
- D. reduce the freezing point of ice
Alloys are best prepared by
- A. electroplating
- B. Arc-welding
- C. reducing and mixture of their metallic
- D. cooking a molten of the metals
Electronic configuration of an element 13 in the subsidiary energy level is
- A. \( 1s^2 2s^2 2p^6 3s^2 3p^1 \)
- B. \( 1s^22s^2 2p^4 3p^1 3s^1 \)
- C. \( 1s^2 2s^2 2p^6 3s^2 3p^3 \)
- D. \( 1s^1 2s^2 2p^6 3s^2 3p^4 \)
Which of the following gives a precipitation when treated with NaOH Solution?
- A. AlCl3
- B. NH4Cl
- C. Na2CO3
- D. CH3COONa
PCL5(g)= PCL3(g) + Cl2(g)
In the reaction above, a decrease in pressure will
- A. Decelerate the reaction
- B. Increase yield of Pcl3
- C. Increase the yield of Pcl5
- D. Accurate the reaction
According to the kinetic theory an absence in temperature causes the kinetic energy of particles to
- A. decrease
- B. increase
- C. remain constant
- D. be zero
A difference between chemical and physical change is that in a chemical change
- A. oxygen is consumed
- B. heat is supplied
- C. the reversible process occurs
- D. a new substance is formed