Which compound is a component of baking powder?
- A. Na2CO3
- B. Na2SO4
- C. KH2CO3
- D. NaHCO3
- E. NaHSO4
if an element X with atomic number 13 combines with an element Y whose atomic number is 8 the most likely formula of the compound formed between X and Y is?
- A. XY
- B. X2Y
- C. XY2
- D. X3Y2
- E. X2Y3
When an electric current is passed through a solution containing dilute tetraoxosulphate (Vi) acid, 190 cm3 of hydrogen gas is evolved. if the measurements were made at 26Β°C and 736 mmHg, what is the volume of hydrogen at s.t.p.?
- A. 164 cm3
- B. 168 cm3
- C. 179.1.cm3
- D. 201.5cm3
- E. 546 cm3
A measure of the degree of disorderliness in a chemical system is known as the
- A. activation energy
- B. enthalpy
- C. entropy
- D. equilibrium
- E. free energy.
Fructose and glucose are
- A. allotropes of each other.
- B. both disaccharides
- C. dimere of each other.
- D. isomers of each other
- E. isotopes of each other
Detergents are better than soaps for washing in hard water because
- A. hard water contains insoluble calcium salts.
- B. they contain bleaching powder.
- C. they contain palmitic acid.
- D. they do not form insoluble calcium and magnesium salts.
- E. they are organic compounds.
Which method is NOT used to determine rate of a reaction?
- A. change in amount of precipitate formed
- B. change in equilibrium constant
- C. change in intensity of colour
- D. change in pH values.
- E. change in total gas pressure
Ethanol is a product of fermentation of simple sugars. Which method is used to separate ethanol from the other products?
- A. boiling off the ethanoic
- B. filtration
- C. fractional crystallisation
- D. fractional distillation
- E. isomerisation
To test for the presence of chloride ions in ion, correct sequence of reagents to use is
- A. Ba(NO3)2(aq) then HNO3(aq).
- B. HCl(aq) then Ba(NO3)2(aq).
- C. HCl(aq) then Ag3(aq).
- D. HNO3(aq) then fresh FeSO4(aq).
- E. HNO3(aq) then AgNO3(aq).
NaCl(s) does NOT conduct electricity, but N(aq) does. This is because
- A. NaCl(s) is non-ionic but NaCl(aq) is ion
- B. NaCl(aq) contains mobile electrons, where absent in NaCl(s).
- C. NaCl(aq) contains mobile ions which Nacl,) does not contain.
- D. NaCl(s) ionizes partiality while NaCl(aq) iodizes completely.
- E. NaCl(s) decomposes when heated but NCl(aq) is stable to heat. β
The green colour solution of an Fe2 salt changes to a brown solution of an Fe3+ salt by
- A. conversion.
- B. elimination.
- C. oxidation.
- D. reduction.
- E. substitution.
A gas X diffuse through porous partition at the rate of 3 cm3 per second. Under the same condition hydrogen diffused at the rate of 15 cm3 per second.
What is the 42. relative molecular mass of X.
- A. 5
- B. 12
- C. 18
- D. 45
- E. 50
Faraday s first law of electrolysis can be expressed mathematically as
- A. m=I/it
- B. mΞ±it
- C. Q=it
- D. QΞ±I/it
- E. QΞ±it
An experiment to test the conductance of 0,1 M solutions of the substances listed below was perform.
I ammonia
II ammonium chloride
III ethanoic acid
IV sodium ethanoate
Which pair of substances show the least conductance?
- A. I and II
- B. I and III
- C. I and IV
- D. II and III
- E. II and IV
The best way to distinguish between Na2CO3and NaHCO2 is by.
- A. adding an acid.
- B. adding an alkali.
- C. dissolving in water.
- D. exposing to air.
- E. heating.
The Kinetic theory can NOT be used to explain
- A. allotropy.
- B. Brownian movement.
- C. diffusion.
- D. Tyndal effect.
- E. vaporization.
The molar mass of a compound X is 56. its empirical formula is CH2. X is
- A. butene.
- B. butyne.
- C. ethene.
- D. propene.
- E. propyne
Which compound will have the lowest boiling point?
- A. CH3OH
- B. CH3COOH
- C. CH3CHOH
- D. C4H10
- E. (CH3)3CH
The Atomic theory model which explains that electrons in an atom revolve round quantized energy levels is attributed to
- A. Becquerel.
- B. Bohr.
- C. de Broglie.
- D. Rutherford.
- E. Thompson.
White is NOT a property of metals?
- A. ductile:
- B. malleable
- C. conduct heat and electricity
- D. have many oxidation states
- E. high melting points anti boiling points
Which of the following is TRUE of a catalyst? I. it alters the activation energy of a reaction
II. it is effective in a reaction but cannot initiate a reaction
III, it affects the equilibrium of a reversible reaction
IV. it affects the overall reaction
- A. I and II only
- B. I, II and III only
- C. II and III only
- D. II, II and IV only
- E. III and IV only