Chemistry Past Questions And Answers
The reaction of vegetable oil with a solution of wood ash is
- A. saponification
- B. neutralization
- C. hydrogenation
- D. esterification
Which of the following compounds of trioxonitrate (V) will decomposes to give dinitrogen (i) oxide and water when heated?
- A. NaNO
- B. Zn(NO
- C. Cu(NO
- D. NH
NO
The oxidation state of oxygen in tetraoxosulphate(IV) acid is
- A) -4
- B) +4
- C) -2
- D) +2
Which of the following is needed to produce a slag during the extraction of iron in the blast furnace?
- A) cryolite
- B) limestone
- C) carbon
- D) sulphur
The existance of two or more forms of the same element in the same physical state is known as
- A. allotropy
- B. resonance
- C. hybridization
- D. isotopy
What is the molecular formula of a compound whose empirical formula is CH2O and molar mass is 180? (H = 1, C = 12, O = 16)
- A. C2H8O2
- B. C4H8O3
- C. C6H10O5
- D. C6H12O6
The seperation of Nitrogen from oxygen using fractional distillation of air is possible because
- A. nitrogen is less dense than oxygen
- B. oxygen is more reactive than nitrogen
- C. of the difference in their boiling points
- D. they belong to the same period
AQUEOUS Sodium trocarbonate (IV) solution is alkaline because
- A. the acid from which is formed is strong
- B. sodium is an alkali metal
- C.sodium trioxocarbonate (IV) is hydrolysed in water
- C.sodium trioxocarbonate (IV) is decomposed by water
What is the pH of 2.5 × 10-2 mol dm-3 barium hydroxide solution?
- A) 11.5
- B) 11.6
- C) 11.7
- D) 11.8
(a) i) An organic compound X contains 40% carbon, 6.67% hydrogen, the rest being oxygen. If X has a relative molecular mass of 60, determine its
(i) empirical formula (ii) molecular formula. [H = 1 ; C = 12; O = 16]
(b) An alkanoic acid Y has a relative molecular mass of 74.
(i) State the functional group of Y
(ii) What t of reaction is involved when Y is converted to an alkanoate?
(iii) Determine the structural formula of Y.
(iv) Write an equation for the reaction between Y and sodium
(v) If X in (a) above boils at 118°C and belongs to the same homologous series as Y, state with reason, whether the boiling point of Y will be equal to, higher or lower than 118°C.
(c)(i) What is fermentation?
(ii) Write an equation for the fermentation of glucose.
(iii) What must be added to glucose solution to make it ferment?
(iv) Explain why a tightly corked grass bottle filled to the brim with fresh palm wine shatters on standing.
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