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Class 10 Chemistry Chapter 24 Carboxylic Acids Test 3 PDF | Punjab Board 2027 Model Papers
Grade 10 Chemistry Chapter 24 Carboxylic Acids Test 3
Prepare for the Class 10 Chemistry Chapter 24: Carboxylic Acids examination with our Punjab Board 2027 Model Papers. This study resource includes Class Test 3, Full Unit Test, and Chapter-Wise Test Series, prepared according to the new syllabus issued by PECTAA Punjab. These Class 10 Chemistry test papers help students revise important concepts, practise exam-style questions, assess their preparation, and improve their performance in the Punjab Board examinations. Students can use these Chemistry Chapter 24 test papers for effective revision and exam preparation.
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Chapter: 24
Total Time: 35 min
CHAPTER WISE CLASS TEST
(Test # 3)
Chemistry
Total Marks: 25
ABCD
1ABCD
2ABCD
3ABCD
ABCD
4ABCD
5ABCD
6ABCD
ABCD
7ABCD
8ABCD
NOTE: Four possible answers A, B, C and D to each question are given. The choice which you think is correct, fill that circle in front of that question with Marker or Pen ink. Cutting or filling two or more circles will result in zero mark in that question.
TIME: 10 Min
OBJECTIVE
MARKS: 8
Q.1:(08)
1.
Identify the ester functional group:
(A) –COOR(B) –COOH(C) C=O(D) –CH2–OH
Ans: (A) –COOR
2.
Organic acids are also called:
(A) Mineral acids(B) Carboxylic acids(C) Inorganic acids(D) Strong acids
Ans: (B) Carboxylic acids
3.
During the oxidation of ethanol by acidified KMnO4, which element is reduced?
(A) K(B) O(C) Mn(D) H
Ans: (C) Mn (Mn is reduced from +7 to +2)
4.
In oxidative fermentation, alcoholic food stuffs are converted to vinegar in presence of:
(A) Yeast only(B) Bacteria with sufficient oxygen(C) Enzymes only(D) Acid catalysts
Ans: (B) Bacteria with sufficient oxygen
5.
Fermentation of food stuff in the presence of acetic acid bacteria needs a sufficient supply of oxygen. What is the role of oxygen in this process?
(A) It enhances the reactivity of bacteria(B) It oxidizes ethanol which is formed during the reaction(C) It inhibits the destruction of bacteria(D) It inhibits the oxidation of acetic acid
Ans: (B) It oxidizes ethanol which is formed during the reaction
6.
Reactions of carboxylic acids with bases are:
(A) Oxidation reactions(B) Reduction reactions(C) Simple neutralization reactions(D) Addition reactions
Ans: (C) Simple neutralization reactions
7.
Which organic acid is used as a component of food?
(A) Formic acid(B) Oxalic acid(C) Propanoic acid(D) Acetic acid
Ans: (D) Acetic acid
8.
The reaction of carboxylic acid with alcohol to form ester is called:
(A) Saponification(B) Hydrogenation(C) Esterification(D) Hydration
Ans: (C) Esterification
TIME: 25 Min
SUBJECTIVE
MARKS: 17
(PART – I)
Q.2 Write short answers to following questions.(6×2=12)
i.
What is an esterification reaction?
Ans: The reaction of a carboxylic acid with an alcohol in the presence of conc. H2SO4 to form an ester and water.
ii.
What is the colour change observed during oxidation of ethanol by KMnO?
Ans: The purple colour of KMnO4 changes to colourless.
iii.
Name an oxidizing agent used to oxidize alcohols.
Ans: Acidified potassium permanganate (KMnO4) or acidified potassium dichromate (K2Cr2O7).
iv.
How do carboxylic acids react with bases?
Ans: They undergo neutralization to form a salt and water:
CH3COOH + NaOH → CH3COONa + H2O
CH3COOH + NaOH → CH3COONa + H2O
v.
What is the role of carboxylic acids in the preparation of beverages?
Ans: Acids such as citric and carbonic acid give a sour, tangy taste and flavour to soft drinks and juices, and also act as preservatives.
vi.
What gas is produced when ethanoic acid reacts with carbonates?
Ans: Carbon dioxide (CO2) gas.
(PART – II)
Note: Attempt the following question.
Q.3: Explain the reactions of carboxylic acids with metals and carbonates.(5)
With metals: carboxylic acids react (slowly, being weak acids) with active metals to form a salt and hydrogen gas.
2CH3COOH + Mg → (CH3COO)2Mg + H2↑
With carbonates: they form a salt, water and carbon dioxide, with brisk effervescence; the gas turns lime water milky.
2CH3COOH + Na2CO3 → 2CH3COONa + H2O + CO2↑
2CH3COOH + CaCO3 → (CH3COO)2Ca + H2O + CO2↑
2CH3COOH + Mg → (CH3COO)2Mg + H2↑
With carbonates: they form a salt, water and carbon dioxide, with brisk effervescence; the gas turns lime water milky.
2CH3COOH + Na2CO3 → 2CH3COONa + H2O + CO2↑
2CH3COOH + CaCO3 → (CH3COO)2Ca + H2O + CO2↑
