Chemistry Past Questions And Answers
The by-product of the fermentation of sugar to ethanol is
- A. propane -1,2,3-triol
- B. ethyl ethanoate
- C. ethanedioc acid
- D. carbon (lV) oxide
If a gas occupies a container of volume 146 cm3 at 18°C and 0.97`atm, its volume 146cm3 at s.t.p is?
- A. 133
- B. 146
- C. 266
- D. 292
Which of the following will produce a solution with pH less than 7 at equivalent point?
- A) HNO 3 +NaOH
- B) H 2SO 4 + KOH
- C) HC +Mg (OH) 2
- D) HNO 3 + KOH
The following will decolourize acidified potassium tetraoxomanganate (VII) solution except
- A. sulphur (lV) oxide
- B. but-3-ene
- C. pentane
- D. hydrogen sulphide
What volume of carbon (lV) oxide is produced at s.t.p. when 2.5g of CaCO3reacts with excess acid according to the following equation? CaCO3+ 2HCI → CaCI3 +H2O + CO2 [CaCO3 = 100; molar volume of a gas at s.t.p = 22.4dm3]
- A. 11.20dm3
- B. 5.60dm3
- C. 2.24dm3
- D. 0.56dm3
The diagram below best illustrates the effect of decrease in
- A) concentration
- B) temperature
- C) surface area
- D) pressure
The gaseous product formed when ammonia is passed over heated copper (ll) oxide is
- A. oxygen
- B. nitrogen
- C. hydrogen
- D. nitrogen (l) oxide
What is the empirical formula of a compound containing 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?
- A. C\(_4\)H\(_8\)O\(_4\)
- B. CH\(_2\)O
- C. C\(_2\)H\(_4\)O\(_2\)
- D. C\(_3\)H\(_6\)O\(_3\)
The production of biogas from the fermentation of waste materials is an example of
- A. combustion
- B. incineration
- C. refining
- D. recycling
Dynamic equilibrium describes a situation where
- A. a reaction gives back the reactant
- B. te concentration of the reactant and products is equal
- C. both forward and and reverse reactions proceed at the same rate
- D. reactants are converted to products