English Medium कक्षा १० - CBSE Question Bank Solutions for Science

While studying saponification reaction for the preparation of soap, a teacher suggested to a student to add a small quantity of common salt to the reaction mixture. The function of common salt in this reaction is to

(A) reduce the alkalinity of the soap

(B) reduce the acidity of the soap

(C) enhance the cleansing capacity of soap

(D) favour precipitation of soap

A student takes about 6 ml of distilled water in each of the four test tubes P, Q, R and S. He then dissolves an equal amount of four different salts namely, sodium chloride in 'P', potassium chloride in 'Q', calcium chloride in 'R' and magnesium chloride in 'S'. Next, he then adds 10 drops of soap solution to each test tube and shakes its contents. The test tubes in which scum (insoluble substance) is formed with soap are:

(A) P and Q

(B) Q and R

(C) R and S

(D) Q and S

What are esters ?

How esters are prepared ?

List two uses of esters.

Complete the following chemical equation:

\[\ce{CH3COOC2H5 + NaOH ->}\]

Complete the following chemical equations :CH₃COOH+NaOH→

Complete the following chemical equations:

C₂H₅OH+CH₃COOH`("conc."H_2SO_4)/`>

You have four test tubes, A, B, C and D containing sodium carbonate, sodium chloride, lime water and blue litmus solutions respectively. Out of these the material of which test tube/ test tubes would be suitable for the correct test of acetic/ethanoic acid?

(a) only A
(b) A and B
(c) B and C
(d) A and D

A gas is liberated immediately with a brisk effervescence, when you add acetic acid to sodium hydrogen carbonate powder in a test tube. Name the gas and describe the test that confirms the identity of the gas. 

Complete the following chemical equations :CH₃COOH + Na₂CO₃ →

Complete the following chemical equations : C₂H₅OH + Na →

Complete the following chemical equations: C₂H₅OH+O₂→

Complete the following chemical equations : C₂H₅OH`("Conc."H_2SO_4)/(443K)`>

Complete the following chemical equations: CH₃COOH+NaHCO₃→

When you add a few drops of acetic acid to a test-tube containing sodium bicarbonate powder, which one of the following is your observation?

(A) No reaction takes place

(B) A colourless gas with pungent smell is released with brisk effervescence

(C) A brown coloured gas is released with brisk effervescence

(D) Formation of bubbles of a colourless and odourless gas

What is the common name of  methanoic acid.