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Class 10 Chemistry Chapter 22 Hydrocarbons Class Test 6 PDF | Punjab Board 2027 Model Papers
Grade 10 Chemistry Chapter 22 Hydrocarbons Test 6
Prepare for your Class 10 Chemistry Chapter 22: Hydrocarbons Class Test 6 with our chapter-wise test series for the Punjab Board 2027 Model Papers. This test covers Topics 22.4 to 22.5 from the prescribed Chemistry textbook, following the new syllabus issued by PECTAA Punjab. These Class 10 Chemistry chapter-wise tests are designed to help students revise important concepts, strengthen their exam preparation, and assess their understanding of Hydrocarbons. Students can use this test as part of their regular practice for the Punjab Board examinations 2027.
Chapter Wise Class Test
Test No. 6
Chapter-22
Hydrocarbons
1.Major sources of organic compounds is:
(a) Coal(b) Petroleum(c) Natural gas(d) All
Answer: (d) All – coal, petroleum and natural gas are all major sources.
2.Coal is a major source of ______ hydrocarbons.
(a) aliphatic(b) Aromatic(c) Heterocyclic(d) Alicyclic
Answer: (b) Aromatic
3.After the flow of gases ceases, petroleum taken out with the helps of:
(a) valves(b) pumps(c) cranes(d) compressor
Answer: (b) pumps
4.Aromatic hydrocarbon, benzene may be produced from.
(a) n-Hexane(b) Propane(c) natural gas(d) Fuels
Answer: (a) n-Hexane (by reforming / cyclization and dehydrogenation).
5.Crude Petroleum is heated at
(a) 400°C(b) 450°C(c) 500°C(d) 550°C
Answer: (a) 400°C
6.First step of refining process is:
(a) Neutralization(b) Heating(c) To pass in Fractionating column(d) All
Answer: (a) Neutralization
7.Boiling range of Fuel oil is
(a) 170–250°C(b) 250–340°C(c) 340–500°C(d) Above 500°
Answer: (c) 340–500°C
8.Hydrocarbons with low molecular mass have
(a) High Boiling Point(b) High viscosity(c) High volatility(d) Low Volatility
Answer: (c) High volatility
Chapter Wise Class Test
Test No. 6
Chapter-22
Hydrocarbons
2. Write short answers to any six (6) questions.[6 × 2 = 12]
- (i)Why are alkene reactive?Alkenes contain a carbon–carbon double bond (one σ and one weak π bond). The π electrons are loosely held and easily attacked by electrophiles, so alkenes readily undergo addition reactions.
- (ii)Write the sources of organic compound.The major sources are coal, petroleum and natural gas. Plants and animals are also natural sources.
- (iii)Where are petroleum and natural gas found underground?They are found trapped in porous rocks (sandstone / limestone) beneath impervious rock layers, usually with natural gas on top, petroleum in the middle and salt water at the bottom.
- (iv)Write the uses of Benzene.
- Used as a solvent for fats, resins, paints.
- Starting material for dyes, drugs, explosives, plastics, detergents and insecticides.
- (v)Define Petroleum.Petroleum (rock oil) is a dark brown / greenish, viscous liquid mixture of hydrocarbons found beneath the earth’s crust. It is the main source of fuels and organic compounds.
- (vi)Write any two steps of refining process.
- Neutralization / removal of impurities such as water, salts and sulphur compounds.
- Heating the crude oil (about 400°C) and passing it into the fractionating column.
- (vii)How fraction of Petroleum is collected?Heated crude oil vapours rise up the fractionating column. Each fraction condenses at its own temperature level and is collected from the tray (outlet) at that height.
- (viii)Write the uses, Boiling range of Lubricating oil?Boiling range: about 300–370°C (above diesel, before fuel oil). Uses: lubricating machines and engines to reduce friction; making vaseline and polishes.
- (ix)Write uses of Gasoline and kerosene oil.Gasoline: fuel for cars and motorcycles; solvent. Kerosene oil: fuel for stoves, lamps and jet engines.
Note: Attempt any one question.[5 × 1 = 5)
3.
Describe the fractional distillation of petroleum.
Crude oil is heated to about 400°C in a furnace. The hot vapours enter the lower part of a tall fractionating column that is hotter at the bottom and cooler at the top. Vapours rise and condense at different heights according to their boiling points: gases (below 40°C) at the top, then gasoline, kerosene oil, diesel oil, lubricating oil, fuel oil, and finally residue (bitumen / asphalt) at the bottom. Each fraction is collected separately.
4.
Explain Physical Properties of different Petroleum Fractions
As molecular mass increases from the top to the bottom of the column: boiling point increases, viscosity increases, volatility decreases, and the colour becomes darker. Light fractions (gases, gasoline) are colourless, highly volatile and flow easily; heavy fractions (lubricating oil, fuel oil, bitumen) are thick, dark and less volatile.
