MHT CET 2016 :: Chemistry :: General questions

• Chemistry - General questions

Mathematical equation of first law of thermodynamics for isochoric process is

Answer:

Explanation:

For an isochoric  process, $\triangle $ V=0

In this process, the first law of thermodynamics

 q= $\triangle U-W$

 q= $\triangle U-p \triangle  V$

 As  $\triangle V=0$

   qV= $\triangle $U

What is the highest oxidation state exhibited  by group 17 elements?

Answer:

Explanation:

The highest oxidation state exhibited by group 17 elements is +7. The elements that belong to group 17 are called halogens. All elements of this group have seven electrons in their outermost shell . So , these elements can lose seven electron to get +7 oxidation state

Identify  the metal that forms  colourless  compounds

Answer:

Explanation:

 d-block elements show +3 as the most common oxidation state. For scandium (Z=21) , electronic configuration  d¹s². After the removal of +3 electrons

(Sc³⁺)  , it acquires a stable configuration (d⁰) . Hence , it forms colourless compounds.

Which among the following phenolic compound is most acidic in nature?

Answer:

Explanation:

The order for acidity in phenols depends upon the position of electron withdrawing groups, -NH₂ is an electron releasing group. Hence , it decreases the acidity of phenols.

 p-nitrophenol  > m-nitrophenol  > phenol > p-aminophenol,

The relation between the solubility of a gas in liquid at constant temperature and external pressure is stated by which law?

Answer:

Explanation:

 The relationship  between solubility of a gas in liquid  at constant temperature and external pressure is given by Henry's law . x$\propto$ Partial pressure of the gas,p

 p= K_H x

Here, K_H = Henry's law constant

More the value of K_H , lower is the solubility of gas

• Chemistry - General questions