Chemistry Past Questions And Answers
Which of the following gasses is highly soluble in water at room temperature
- A. ammonia
- B. carbon (IV) oxide
- C. chlorine
- D. nitrogen
The partial pressure of oxygen in a sample of air is 452mmHg and the total pressure is 780mmHg. What is the mole fraction of oxygen?
- A) 0.203
- B) 0.579
- C) 2.060
- D) 5.790
Which quantum number divides shells into orbitals?
- A) principal
- B) Arzimuthal
- C) Magnetic
- D) Spin
Calculate the volume in cm3 of oxygen evolved as s.t.p. when a current of 5 A is passed through acidified water for 193s {F = 96500 Cmol-1, Molar volume of a gas at s.t.p. = 22.4 dm3
- A) 224.000 dm3
- B) 0.056 dm3
- C) 0.224 dm3
- D) 56.000 dm3
The oxidation number of chlorine is +1 in
- A)KClO3
- B)Cl2O7
- C)ZnCl2
- D)NaClO
The oxidizing agent commonly used for conversion of alcohol to aldehyde is
- A) Potassium dichromate (iv)
- B) Potassium dichromate (v)
- C) Potassium dichromate (vi)
- D) Potassium dichromate (vii)
Separation of mixtures of solids by physical methods can be based on differences in the following except
- A) Melting point
- B) Solubility
- C) Particle size
- D) Molar mass
The energy evolved when magnesium burns in air is in the form of
- A. heat
- B. heat and sound
- C. light and heat
- D. sound
Which of the following compounds determines the octane rating of petrol?
- A. 1,2,3 - trimethyl pentane
- B. 2,3,5 - trimethyl octane
- C. 2,3,5 - trimethyl pentane
- D. 2,2,4 - trimethyl pentane
In an electrolytic set-up to protect iron from corrosion, the iron is?
- A. made cathode
- B. made anode
- C. used with a metal of lower electropositive potential
- D. initially coated with tin