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Class 10 Chemistry Chapter 24 Carboxylic Acids Test 5 PDF | Punjab Board 2027 Model Papers
Download the Class 10 Chemistry Chapter 24 Carboxylic Acids Test 5 PDF, prepared according to the new syllabus issued by PECTAA Punjab. This Punjab Board 2027 Model Paper covers textbook topics 24.1 to 24.3 and is designed as a Half Unit Test to help students prepare for board examinations. This chapter-wise test series supports Class 10 students in revising important concepts, assessing their understanding, and preparing effectively for the Punjab Board Chemistry examination 2027.
Chapter Wise Class Test
Test No.5
Chapter-24
Carboxylic Acids
1.
Carboxylic acid contain functional group.
(a) –OH(b) –COOH
(c)
O||– C – O
(d) –CHO
Answer: (b) –COOH
2.
Carboxylic acid are generally weak acids due:
(a) Not dissolve in water(b) They are solid(c) Easily give proton(d) do not easily give proton
Answer: (d) do not easily give proton
3.
The intermediate product formed during oxidation of ethanol to ethanoic acid is:
(a) Methanol(b) Methanoic acid(c) Ethanal(d) Ethene
Answer: (c) Ethanal
4.
In 24 hours, vinegar containing ethanoic acid by fermentation process.
(a) 12%(b) 13%(c) 14%(d) 15%
Answer: (d) 15%
5.
Which one of following is weak acid?
(a) Hydrochloric acid(b) Carboxylic acid(c) Sulphuric acid(d) Nitric acid
Answer: (b) Carboxylic acid
6.
Which gas is evolved when ethanoic acid react with magnesium?
(a) Oxygen(b) Carbon dioxide(c) Nitrogen(d) Hydrogen
Answer: (d) Hydrogen
7.
Formula of marble chips is:
(a) CaO(b) CaCO3(c) CH3COOH(d) Na2CO3
Answer: (b) CaCO3
8.
Which one of following used catalyst in esterification reaction?
(a) Na2CO3(b) C2H5OH(c) H2SO4(d) HNO3
Answer: (c) H2SO4
Chapter Wise Class Test
Test No.5
Chapter-24
Carboxylic Acids
2. Write short answers to any six (6) questions.[6 × 2 = 12]
- (i)What is carboxylic acids? Give example.Organic compounds containing the carboxyl group (–COOH) are carboxylic acids. Example: ethanoic (acetic) acid, CH3COOH.
- (ii)What types of substance can be converted to vinegar?Sugary or starchy substances such as fruit juices (apple, grape), molasses, sugar cane juice and malt can be converted to vinegar.
- (iii)Why is liquid stirred continuously during fermentation?To mix the liquid with air (oxygen) and spread the bacteria evenly so oxidation of ethanol is faster.
- (iv)Write a chemical reaction of acetic acid with base.CH3COOH + NaOH → CH3COONa + H2O
- (v)How ester formed? Give equation.A carboxylic acid reacts with an alcohol in the presence of conc. H2SO4 (catalyst):
CH3COOH + C2H5OH → CH3COOC2H5 + H2O - (vi)Can you oxidize methanol with KMnO4, just like ethanol?Yes. Methanol is oxidized by KMnO4 first to methanal and then to methanoic acid (HCOOH).
- (vii)Is ethanoic acid a weak acid?Yes. It ionizes only partially in water, so it gives few H+ ions and does not easily give protons.
- (viii)How will calcium carbonate react with ethanoic acid?2CH3COOH + CaCO3 → (CH3COO)2Ca + H2O + CO2↑ (brisk effervescence).
- (ix)Why is oxygen supplied continuously in vinegar preparation?Acetobacter bacteria need oxygen to oxidize ethanol to ethanoic acid; without oxygen the reaction stops.
Note: Attempt any one question.[5 × 1 = 5]
- 3.Explain fermentation reaction which is used to prepare acetic acid on commercial scale.Sugary liquid is first fermented by yeast to ethanol: C6H12O6 → 2C2H5OH + 2CO2. The ethanol solution is trickled over wood shavings with Acetobacter bacteria while air is supplied and the liquid is stirred: C2H5OH + O2 → CH3COOH + H2O. In about 24 hours vinegar with ~15% ethanoic acid is obtained.
- 4.Explain reactions of carboxylic acids with metals and carbonates.With metals: 2CH3COOH + Mg → (CH3COO)2Mg + H2↑
With carbonates: 2CH3COOH + Na2CO3 → 2CH3COONa + H2O + CO2↑
Hydrogen gas and carbon dioxide gas are evolved respectively.
