Questions

Mixtures are combination of two or more substances physically which can be separated in to the original.

Matter can be breakdown into two categories. 

1) Pure substances 

2) Mixtures

Here in the given options, options A, B, C are pure substances as they are indicated as S & L in brackets. Option D) is an aqueous solution, that can be dissolved in water.

The boring of India’s first underwater rail tunnel under the Hooghly River for establishing metro link between Howrah and Kolkata has completed before its scheduled deadline of July 2017. The tunnel is 16.6 km long, out of which 10.8 km runs under the ground. Of this 10.8 km, 502 metres is under the water and the whole thing connects Howrah to the west and Salt lake to the east. It will have 12 stations and six will be underground. Estimated cost of the entire project is $750 million or about Rs 5,000 crores. The final commissioning of the project is expected by December 2019, following which it will be operational. The project is built by Afcons Transtonnelstroy and implemented by Kolkata Metro Railway Corporation Ltd (KMRCL).

Entropy is a measure of disorder . It will be maximum in gases followed by liquids and least in solids.

Hence, here the gas is only hydrogen and it has the highest entropy.