English Medium Class 10 - CBSE Question Bank Solutions for Science

A student takes 2 mL acetic acid in a dry test tube and adds a pinch of sodium hydrogen carbonate to it. He makes the following observations:

I. A colourless and odourless gas evolves with a brisk effervescence.

II. The gas turns lime water milky when passed through it.

III. The gas burns with an explosion when a burning splinter is brought near it.

IV. The gas extinguishes the burning splinter that is brought near it.

The correct observations are:

(A) I, II, and III

(B) II, III and IV

(C) III, IV and I

(D) IV, I and II

In an experiment to study the properties of acetic acid a student takes about 2 mL of acetic acid in a dry test tube. He adds about 2 mL of water to it and shakes the test tube well. He is likely to observe that:

(A) the acetic acid dissolves readily in water

(B) the solution becomes light orange

(C) water floats over the surface of acetic acid

(D) acetic acid floats over the surface of water

Name the functional group present in the following compound:
HCOOH

Name the functional group present in the following compound:
C₂H₅CHO

Which of the following observations is true about dilute solution of acetic acid?

(A) It smells like vinegar and turns red litmus blue

(B) It smells like onion and turns blue litmus red

(C) It smells like orange and turns red litmus blue

(D) It smells like vinegar and turns blue litmus red

Which of the following observations is true about dilute solution of acetic acid?

(A) It smells like vinegar and turns red litmus blue

(B) It smells like onion and turns blue litmus red

(C) It smells like orange and turns red litmus blue

(D) It smells like vinegar and turns blue litmus red

A student takes Na₂CO₃ powder in a test tube and pours some drops of acetic acid over it. He observes:

(A) no reaction in the test tube

(B) colourless gas with pungent smell

(C) bubbles of a colourless and odourless gas

(D) white fumes with smell of vinegar

A student adds 4 mL of acetic acid to a test tube containing 4 mL of distilled water. He then shakes the test tube and leaves it to settle. After about 10 minutes he observes:

(A) a layer of water over the layer of acetic acid

(B) a layer of acetic acid over the layer of water

(C) a precipitate settling at the bottom of the test tube

(D) a clear colourless solution

On adding 2 mL acetic acid to 2 mL of water in a test tube, it was observed that

(A) a clear and transparent solution is formed

(B) a white precipitate is formed almost immediately

(C) two separate layers were formed

(D) a colourless and odourless gas is evolved

On adding acetic acid to sodium hydrogen carbonate in a test tube, a student observes

(A) no reaction

(B) a colourless gas with pungent smell

(C) bubbles of a colourless and odourless gas

(D) a strong smell of vinegar

Which one of the following are the correct observations about acetic acid?

(A) It turns blue litmus red and smells like vinegar

(B) It turns blue litmus red and smells like burning sulphur

(C) It turns res litmus blue and smells like vinegar

(D) It turns red litmus blue and has a fruity smell

Acetic acid smells like: 

(1) a banana 

(2) vinegar 

(3) an orange

(4) a lemon 

Acetic acid solution turns: 

(1) blue litmus red 

(2) red litmus blue 

(3) blue litmus colourless 

(4) red litmus colourless 

On adding NaHCO3 to acetic acid, a gas is evolved which turns lime water milky due to the formation of:

(1) Calcium bicarbonate 

(2) Calcium hydroxide

(3) Calcium carbonate 

(4) Calcium acetate 

Write the chemical equation for the following:

Combustion of methane

Choose the correct option from given alternative:
When sodium hydrogen carbonate is added to ethanoic acid a gas evolves. Consider the following statements about the gas evolved?
(A) It turns lime water milky.
(B) It is evolved with brisk effervescence.
(C) It has a smell of burning sulfur.
(D) It is also a by-product of respiration.

Assertion (A): Esterification is a process in which a sweet-smelling substance is produced.

Reason (R): When esters react with sodium hydroxide an alcohol and sodium salt of carboxylic acid are obtained.

Distinguish between esterification and saponification reactions with the help of chemical equations for each.

With a labelled diagram describe in brief an activity to show the formation of ester.

Mineral acids are stronger acids than carboxylic acids because

1. mineral acids are completely ionised
2. carboxylic acids are completely ionised
3. mineral acids are partially ionised
4. carboxylic acids are partially ionised