Chemistry Past Questions And Answers
Which of the following statements about soapless detergents is correct? They
- A. lather readily with hard water
- B. increase the surface tension of water
- C. cause hydrolysis of salts in water
- D. from a curdy precipitate with soft water
(a) State Gay Lussac's law of combining volumes
(b) Hydrogen reacts with oxygen according to the following equation;
2H\(_{2(g)}\) + O\(_{2(g)}\) ---> 2H\(_2\)O\(_{(g)}\). If 50cm\(^3\) of hydrogen were sparked with 30cm\(^{3}\) of oxygen, calculate the volume of unused oxygen after cooling to the initial temperature and pressure.
View Discussion (0)WAEC 1997 THEORYThe reaction represented by the equation C + H20 --------> CO + H2 was carried out at 27℃C. If the enthalpy change was +4500J and the entropy was +12J, what was the free energy change? (ΔG=ΔH-TΔS)
- A.+900j
- B. -900J
- C. +4176
- D. -4176
If an equilibrium reaction has ∆H< O, the reaction will proceed favorably in the forward reaction at?
- A. low temperatures
- B. high temperatures
- C. all temperatures
- D. all pressures
Which of the gas laws does this graph illustrate?
- A. Boyle
- B. Charles
- C. Gay-Lussac
- D. Graham
Chlorine is produced commercially by
- A) electrolysis of dilute HCl
- B) electrolysis of brine
- C) neutralization of HCl
- D) heating potassium trioxochlorate (V)
A mixture of iron and sulphur can be separated by dissolving the mixture in _______
- A) steam
- B) dilute hydrochloric acid
- C) dilute sodium hydroxide
- D) benzene
300cm\(^3\) of a gas has a pressure 400mmHg. If the pressure is reduced to 150mmHg. Find its volume.
- A)700cm\(^3\)
- B)800cm\(^3\)
- C)350cm\(^3\)
- D)112.5cm\(^3\)
Alkanes react with the halogens mainly by
- A. oxidation
- B. polymerization
- C. addition
- D. substitution
Which of the following substances is a mixture?
- A. Granulated sugar
- B. Seawater
- C. Sodium chloride
- D. Iron filling