Education
Class 10 Chemistry Chapter 23 Test 1 PDF Download | Monohydroxy Alkanes or Alcohols | Punjab Board 2027
Grade 10 Chemistry Chapter 23 Monohydroxy Alkanes or Alcohols Test 1
Prepare for the Class 10 Chemistry Chapter 23 Test 1 with our latest Punjab Board 2027 Model Papers. This chapter-wise test series covers Chapter 23: Monohydroxy Alkanes or Alcohols, including a Full Unit Test with Exercise, designed according to the new syllabus issued by PECTAA Punjab. These Class 10 Chemistry test papers help students revise important concepts, practise textbook exercises, assess their preparation, and get ready for school examinations and Punjab Board assessments. Download the chapter-wise Chemistry test paper in PDF format for effective exam preparation.
786Times786Times786Times786Times786Times786Times786Times786Times
1.which one of following is monohydroxy alkanes?(Q-1)
(a) Methane(b) Alcohols(c) Propanone(d) Ethanone
Answer: (b) Alcohols – alkanes in which one H is replaced by one –OH group (CnH2n+1OH).
2.Which gas is released during fermentation?(Q-4)
(a) H2(b) Steam(c) CO2(d) NH3
Answer: (c) CO2 – C6H12O6 → 2C2H5OH + 2CO2
3.Optimum temperature for fermentation is:(Q-6)
(a) 10°C(b) 20°C(c) 30°C(d) 35°C
Answer: (d) 35°C (about 35°C is the textbook optimum for yeast enzymes; please verify with your key).
4.Which catalyst is used for the hydration of ethene in industrial scale?(Q-10)
(a) H2SO4(b) H3PO4(c) H3PO3(d) HCl
Answer: (b) H3PO4 (phosphoric acid, at about 300°C and 60–70 atm).
5.Heat energy evolved by the combustion of Propanol is:(Q-13)
(a) 726 KJ/mol(b) 1367 KJ/mol(c) 2017 KJ/mol(d) 2676 KJ/mol
Answer: (c) 2017 KJ/mol (methanol 726, ethanol 1367, propanol 2017 kJ/mol).
6.Alcohol fuels are produced mainly from(Q-18)
a) Plant materialsb) Petroleumc) Coal Tard) metal
Answer: a) Plant materials – sugarcane, corn and other crops are fermented to ethanol.
7.Ethanol fuel reduce greenhouse gas emission by:(Q-23)
a) 22-32%b) 32-52%c) 44-52%d) 45-60%
Answer: c) 44-52% (please verify with your textbook key).
8.Ethanol is widely used in perfumes due to being a:(Q-25)
a) Catalystb) Oxidizing agentc) Reducing agentd) Good solvent
Answer: d) Good solvent
786Times786Times786Times786Times786Times786Times786Times
Attempt any 7 Questions.7×2=14
i.Define monohydroxy alkane.(Q-1)
Monohydroxy alkanes (alcohols) are compounds obtained by replacing one hydrogen atom of an alkane with one hydroxyl (–OH) group. General formula: CnH2n+1OH. Examples: CH3OH, C2H5OH.
ii.Why fermentation must be carried out in the absence of air?(Q-3)
Fermentation by yeast enzymes (zymase) is anaerobic. In the presence of air (oxygen), bacteria oxidise the ethanol formed to ethanoic acid (vinegar), so the ethanol yield is lost.
iii.What is hydration of ethene? Give example.(Q-6)
Hydration is the addition of water (steam) to ethene in the presence of phosphoric acid catalyst (H3PO4) at about 300°C and 60–70 atm to form ethanol.
CH2=CH2 + H2O → CH3CH2OH
CH2=CH2 + H2O → CH3CH2OH
iv.Write characteristics properties of hydration of ethene process?(Q-8)
- Fast, continuous process.
- Gives pure ethanol.
- Needs a catalyst, high temperature and high pressure.
- Reaction is reversible; unreacted ethene is recycled.
- Uses ethene from petroleum (a non-renewable source).
v.Which stronger bond are formed by the combustion of alcohol?(Q-11)
The C=O bonds (in CO2) and O–H bonds (in H2O) formed are stronger than the C–H, C–C, C–O and O=O bonds broken, so a large amount of heat energy is released.
vi.From where are alcohols produced?(Q-15)
By fermentation of sugars and starch (sugarcane molasses, grains, fruits) and by hydration of ethene obtained from petroleum.
vii.Does burning alcohol fuels increase atmospheric CO2(Q-17)
Burning releases CO2, but the plants used to make the alcohol absorbed the same amount of CO2 by photosynthesis. So there is no net increase; alcohol fuels are nearly carbon neutral.
viii.Write any two uses of ethanol in Pharmaceutical industry.(Q-18)
- Solvent for making medicines, tinctures and syrups.
- Antiseptic / disinfectant and in hand sanitizers.
ix.Give four cosmetic products that contain ethanol.(Q-20)
Perfumes, deodorants, hair sprays and after-shave lotions.
x.Give an important property of ethanol which acts as a solvent.(Q-23)
Ethanol dissolves both polar and non-polar substances (it mixes with water and with many organic compounds) and evaporates quickly.
SECTION-II
xi.Give a comparison of fermentation reaction and catalytic hydration of ethene for the preparation of ethanol.(Ex. D. 23.1)
| Fermentation | Catalytic hydration of ethene |
|---|---|
| Raw material: sugar / starch (plants), a renewable source. | Raw material: ethene from petroleum, non-renewable. |
| Slow batch process (days). | Fast continuous process. |
| Yeast enzymes, about 35°C, no air. | H3PO4 catalyst, about 300°C, 60–70 atm. |
| Gives dilute, impure ethanol (needs distillation). | Gives pure ethanol. |
| C6H12O6 → 2C2H5OH + 2CO2 | CH2=CH2 + H2O → C2H5OH |
xii.Describe the applications of ethanol in pharmaceutical and cosmetic industries?(Ex. D. 23.1)
Pharmaceutical: solvent for drugs, tinctures, cough syrups and extracts; antiseptic and disinfectant (hand sanitizers, wound cleaning); preservative.
Cosmetic: good solvent for fragrances in perfumes and deodorants; used in hair sprays, after-shave lotions, creams and nail polish removers because it dissolves many substances and evaporates quickly, leaving a cooling effect.
Cosmetic: good solvent for fragrances in perfumes and deodorants; used in hair sprays, after-shave lotions, creams and nail polish removers because it dissolves many substances and evaporates quickly, leaving a cooling effect.
