Questions

Fischer projections were originally proposed for the depiction of carbohydrates and used by chemists, particularly in organic chemistry and biochemistry.A Fischer projection always uses an eclipsed conformation. A Newman diagram can represent either an eclipsed conformation or a staggered conformation or a skew conformation.

In the dictionary, we get Friday before Thursday. Since, in the dictionary all the words are in alphabetical order, and according to it F comes first than T.

‘Lest’ is always followed by ‘Should’, as it is used to express a purpose. Thus, the correct formation would be, ‘He decided to take the help of a guide lest he should miss the way’.

Kanyakumari is nearest to the Tropic of Capricorn, and the sun's rays fall vertically here during December.

USB - Universal Serial Bus is a secondary type of storage device which is used in all computers, laptops, mobiles...

It is a plug-and-play portable storage device that uses flash memory and is lightweight enough to attach to a keychain.

Hardness can be removed by adding sodium carbonate (washing soda) or by passing the water through an ion-exchange column.

Hardness in water is caused by dissolved magnesium ions and calcium ions. These can get into the water when it comes into contact with limestone and other rocks that contain calcium compounds. This can happen, for example, when rainwater flows over these rocks on its way to a reservoir.

Hardness in water is of two types. They are :

1. Temporary hardness

2. Permanent hardness

1. Temporary hardness:: Temporary hardness is caused by dissolved calcium hydrogen carbonate.

2. Permanent hardness:: Permanent hardness is caused by dissolved calcium sulfate. Unlike temporary hardness, it is not removed by boiling the water.