2024 Chemistry
- At a given temperature and pressure, a gas X diffuses twice as fast as gas Y. It follows that
- A. Gas Y is two times as heavy as Gas X
- B. Gas Y is four times as heavy as Gas X
- C. Gas Y is monoatomic
- D. Gas X is diatomic
- The number of molecules of helium gas contained in 11.5g of the gas is
- A. 1.73 x 1023
- B. 1.73 x 1022
- C. 1.73 x 1024
- D. 1.73 x 1021
- The constituents of Alnico are Aluminium, Nickel and
- A. Mg
- B. Co
- C. Mn
- D. Cu
- Silver and Gold are metals found as free uncombined elements in the earth’s crust, which makes them to be referred to as
- A. corrosive metals
- B. reactive metals
- C. natural metals
- D. noble metals
- In the extraction of Aluminium, the silica impurity is removed by
- A. electrolysis
- B. filtration
- C. reaction with H2SO4
- D. precipitation
- When Calcium ethynide is decomposed by water, the gas produced is
- A. CO
- B. H2
- C. C2H2
- D. CH4
- The constituent of petroleum fraction used in surfacing road is
- A. petrol
- B. diesel
- C. lubricating oil
- D. bitumen
- During the fractional distillation of crude oil, the fraction that distills at 200 – 25000 C is
- A. bitumen
- B. diesel
- C. kerosene
- D. petrol
- A liquid hydrocarbon obtained from fractional distillation of coal tar that is used in the pharmaceutical industry is
- A. xylene
- B. benzene
- C. hexane
- D. Toluene
- An organic compound contains 53.1% Carbon, 6.2% Hydrogen, 12.4% Nitrogen, and 28.3% Oxygen by mass. What is the molecular formula of the compound if its vapour density is 56.5? [ C =12, H = 1, N = 14, O = 16].
- A. C5H7NO2
- B. C5H6NO2
- C. C3H6NO2
- D. C3H7NO2
- The empirical formula of an organic liquid hydrocarbon is XY. If the relative molar masses of X and Y are 72 and 6 respectively, it’s vapour density is likely to be
- A. 33
- B. 66
- C. 39
- D. 78
- Biuret test is a chemical test used for detecting the presence of
- A. carbohydrates
- B. proteins
- C. amines
- D. alkanoates
- A gas when mixed with oxygen, it produces a very hot and early controllable flame. What is the name of the flame and where is it used?
- A. Acetylene flame; miners’ lamb
- B. Oxy-ethylene ; hunters’ torch
- C. Oxy-ethylene flame; miners’ lamb
- D. Oxy-ethylene flame ; cutting and welding metals
- The number of geometrical isomers of butene are
- A. 2
- B. 3
- C. 5
- D. 4
- How many isomers has the organic compound represented by the formula C3H8O ?
- A. 2
- B. 3
- C. 4
- D. 5
- When a few drops of Millon reagents is added to egg-white solution in a test tube, the white precipitate changes to
- A. orange
- B. brick red
- C. reddish brown
- D. blue
- If the solubility of KNO3at 300C is 3.10 mol/dm3a solution containing 303g/dm3 KNO3 is likely to be
- A. saturated
- B. unsaturated
- C. supersaturated
- D. at saturation point
- 127g of sodium chloride was dissolved in 1.0dm3of distilled water at 2500C . Determine the solubility in moldm−3of sodium chloride at that temperature. [Na = 23, Cl = 35.5]
- A. 1.0
- B. 2.0
- C. 2.2
- D. 4.1
- The quantity of electricity required to deposit 180g of Ag from a molten silver trioxonitrate(V) is
[Ag = 108]
- A. 1.08F
- B. 3.30F
- C. 1.67F
- D. 1.80F
- What would be the order of the electrolytic cell in an industry intending the production of silver plated spoons?
- A. Cathode is the spoon; anode is a silver rod; electrolyte is a soluble silver salt
- B. Cathode is a silver rod; anode is the spoon; electrolyte is a soluble silver salt
- C. Cathode is the spoon; anode is any rod; electrolyte is a soluble silver salt
- D. Cathode is any rod; anode is the spoon; electrolyte is a soluble salt
21.
The table above shows the formulae of some ions. In which of these compounds is the formula not correct?
- A. Aluminiumtetraoxosulphate(VI), Al2(SO4)3
- B. Calciumtrioxonitrate(V), Ca(NO3)2
- C. Iron(III)bromide, Fe3Br
- D. Potassiumsulphide, K2S
- The pH of a 0.001 mol dm−3of H2SO4is
[Log102 = 0.3]
- A. 2.7
- B. 3.0
- C. 3.3
- D. 2.0
- Strong acids can be distinguished from weak acids by any of the following methods, EXCEPT
- A. Conductivity measurement
- B. The use of litmus paper
- C. Measurement of pH
- D. Measurement of heat of reaction
- The chemical formula for potassiumhexacyanoferrate(II) is
- A. [Fe(CN)6]4−
- B. K3Fe(CN)6
- C. Fe(CN)6
- D. K4Fe(CN)6
- For chemical reaction to be spontaneous, ∆G must be
- A. positive
- B. negative
- C. zero
- D. equal to the enthalpy change