- The electronic configuration of an element is 1S2 2S2 2P6 3S2 3P3. How many unpaired electrons are there in the element?
- A. 5
- B. 4
- C. 3
- D. 2
Correct Option: Answer is C
2. Which of the following can be obtained by fractional distillation?
- A. Nitrogen from liquid air
- B. Sodium Chloride from sea water
- C. Iodine from solution of Iodine in carbon tetrachloride
- D. Sulphur from the solution of sulphur in carbon disulphide
Correct Option: Answer is A
Fractional distillation is used to separate mixtures into its component parts or fractions with the difference in boiling points between successive fractions must be more than 10°C.
3. Duralumin consists of aluminum, copper?
- A. Zinc and Gold
- B. Lead and Manganese
- C. Nickel and Silver
- D. Manganese and Magnesium
Correct Option: Answer is D
- Duralumin is an alloy made up of 90% aluminum, 4% copper, 0.51% magnesium, and less than 1% manganese.
4. An example of a polysaccharide is?
- A. Dextrose
- B. Mannose
- C. Glucose
- D. Starch
Correct Option: Answer is D
- Polysaccharides are long chains of monosaccharides linked by glycosidic bonds
5. 8g of CH44 occupies 11.2 at S.T.P. What volume would 22g of CH3CH2CH3 occupy under the same condition?
- A. 3.7dm3
- B. 11.2dm3
- C. 22.4dm3
- D. 33dm3
Correct Option: Answer is B
Molar mass of methane = 16g/mol
At S.T.P. its 8g occupies 11.2
so 16g occupies 22.4 dm3
Molar mass of propane = 44g/mol−1−1 occupies 22.4dm3 at S.T.P
so 22g will occupy 11.2dm3
6. The best treatment for a student who accidentally poured conc tetraoxosulphate(vi) on his skin in the laboratory is to wash his skin with?
- A. with cool running water
- B. sodium hydroxide solution
- C. iodine solution
- D. sodium trioxonitrate(v) solution
Correct Option: Answer is A
- Sulfuric acid is flushed with a mild, soapy solution if the burns are not severe. Sulfuric acid feels hot when water is added to the acid, but it is better to flush the area and not leave the acid on the skin.
7. Which of the gas laws does this graph illustrate?
- A. Boyle
- B. Charles
- C. Gay-Lussac
- D. Graham
Correct Option: Answer is B
Charles’ law describes the effect of temperature changes on the volume of a given mass of gas at a constant pressure
8. What are the possible oxidation numbers of an element if its atomic number is 17?
- A. -1 and 7
- B. -1 and 6
- C. -3 and 5
- D. -2 and 6
Correct Option: Answer is A
9. What process would coal undergo to give coal gas, coal tar, ammoniacal liquor and coke?
- A. Steam distillation
- B. Destructive distillation
- C. Liquefication
- D. Hydrolysis
Correct Option: Answer is B
Destructive distillation of a tonne of coal can produce 700 kg of coke, 100 liters of liquor ammonia, 50 liters of coal tar and 400 M3 of coal gas
10. Liquid black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the ?
- A. Acid
- B. Ester of alkanoic acid
- C. Alkali
- C. Alkanol
Correct Option: Answer is C
11. When water drops are added to calcium carbide in a container and the gas produced is passed through a jet and lighted, the resultant flame is called an?
- A. Oxyethene
- B. Oxyhydrocarbon flame
- C. Oxyacetylene flame
- D. Oxymethane flame
Correct Option: Answer is C
12. Which of the following substances is a mixture?
- A. Granulated sugar
- B. Seawater
- C. Sodium chloride
- D. Iron filling
Correct Option: Answer is B
- In chemistry, a mixture is a material made up of two or more different substances which are not chemically combined. A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions and colloids
Smoke and fog (Smog)
Dirt and water (Mud)
Sand, water and gravel (Cement)
Water and salt (Sea water)
Potassium nitrate, sulfur, and carbon (Gunpowder)
13. If the quantity of oxygen occupying 2.76L container at a pressure of 0.825 atm and 300k is reduced by one-half, what is the pressure exerted by the remaining gas?
- A. 1.650atm
- B. 0.825atm
- C. 0.413atm
- D. 0.275atm
Correct Option: Answer is A
Using the combined gas law formula,
Given that P1 = 0.825, V1 = 2.76 L, V2 = 1.38 L, P2 = ?
And T1 = T2; we would have P2 = [ P1 X V1 ] ÷ V2
: [0.825 X 2.76] ÷ 1.38
= 1.650atm
14. Four elements P, Q, R and S have atomic numbers of 4, 10, 12 and 14 respectively. Which of these elements is noble gas?
- A. P
- B. Q
- C. R
- D. S
Correct Option: Answer is B
15. The products of the thermal decomposition of ammonium trioxonitrate(v) are?
- A. Nitrogen (I) Oxide and Water
- B. Ammonia and Oxide
- C. Nitrogen and Water
- D. Nitrogen (IV) Oxide and Water
Correct Option: Answer is A
- NH4NO3 Ammonium Trioxonitrate(V) , unlike all other metallic trioxonitrates(v), decomposes on heating to give nitrogen(i)oxide N2O and water.