Exams

Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH−.

Properties:

1. It is highly soluble in water, and readily absorbs moisture and carbon dioxide from the air.

2. NaOH is insoluble in ether and other non-polar solvents.

3. It is an odorless compound.

Uses:

Sodium hydroxide is used in many industries: in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents, and as a drain cleaner.

Renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat.

Let there be x one rupee coin, y 50 paise coin, z 25 paise coinx + y + z = 220......(i)

Total amount = 160

Now, x + (y/2) + z = 160 ......(ii)

⇒4x + 2y + z = 640

Thrice as many 1 re coin as 25 paise

⇒x = 3z ......(iii)

On solving equation (i), (ii) and (iii), we get

z = 40x= 3* 40 = 120y = 220 –(120 + 40 ) = 60

So, 50 paise coin =60