MENU

Chapter 2– Acids Bases and Salt Solutions

Question - 31 : -
A milkman adds a very small amount of baking soda to fresh milk.

Answer - 31 : -

(a) Why does he shift the pH of the fresh milk from 6 to slightly alkaline?
(b) Why does this milk take a long time to set as curd?

Answer
(a) He shifted the pH of the fresh milk from 6 to slightly alkaline to prevent milk from getting sour due to production of lactic acid.
(b) This milk takes long time to set into curd because the lactic acid produced here first neutralises the pH then the pH is reduced to turn milk to curd.

Question - 32 : - Plaster of Paris should be stored in a moisture-proof container. Explain why?

Answer - 32 : - Plaster of Paris should be stored in moisture-proof container because moisture can affect plaster of Paris by slowing down the setting of the plaster because of hydration. This will turn plaster useless.

Question - 33 : - What is a neutralisation reaction? Give two examples.

Answer - 33 : -

The reaction of the acid + base gives a product of salt + water, which is considered as neutralization reaction.
Examples:

NaOH + HCl → NaCl + H2O

Mg(OH)2 + H2CO3 → MgCO3 + 2H2O

Question - 34 : - Give two important uses of washing soda and baking soda.

Answer - 34 : -

Washing soda

Baking soda

1. It is used as an electrolyte

1. It can be used to test the garden soil for acidity. If bubbles are developed then the soil Is too acidic

2. It can be used domestically as water softener for laundry.

2. If used on washing car then it will remove dead bug bodies without damaging the colour or the paint on the car.

Free - Previous Years Question Papers
Any questions? Ask us!
NodeJS Interview Questions Answers
ASP.Net Interview Questions Answers
Interview Questions Answers
×