Chemistry Past Questions And Answers
The nucleus of the isotope tritium, contains?
- A. two neutrons with no protons
- B. one neutron and one protons
- C. two neutrons and one proton
- D. two neutrons, one proton and one electron
Two radioactive elements Q and S have half-life periods of 10 hours and 20 hours respectively. Therefore
- A. S decays faster than Q
- B. Q is twice as stable as S
- C. Q emits fewer particles than S
- D. S is more stable than Q
Which of the following statements about an equilibrium system is correct?
- A. Forward and backward reactions occur at the same rate
- B. The concentrations of reactants must equal that of the products
- C. The concentrations of, reactants and products can be changed by adding a catalyst,
- D. The concentrations of reactants and products are not affected by a change in temperature
The noble gas, argon,is used for
- A. electric arc welding
- B. welding brass
- C. underwater welding
- D. steel welding
Wine containing 8% to 17% ethanol can be converted to gin containing about 40% ethanol by
- A. evaporation
- B. distilation
- C. fermentation
- D. oxidation
The general formula for the alkanals is
- A. ROH
- B. R2CO
- C. RCOOR1
- D. RCHO
The sub-atomic particles located in the nucleus of an atom are?
- A. neutron and proton
- B. proton and electron
- C. proton and ions
- D. neutron and electron
On exposure to the atmosphere, a hydrated salt loses its water of crystallization to become anhydrous. This phenomenon is referred to as
- A) efflorescence
- B) diliquescence
- C) hygroscopy
- D) hydrolysis
In the extraction of iron, hot air is introduced into the blast furnace through?
- A. valves
- B. open-hearths
- C. arcs
- D. tuyeres
Which of the following will produce oxygen and hydrogen during its electrolysis using platinum electrode?
- A. Glucose solution
- B. Aqueous copper (ll) tetraoxosulphate (IV)
- C. Dilute sodium chloride solution
- D. Concentrated hydrochloric acid