HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

Among dimethylamine (pK_b = 3.27) and diethylamine (pK_b = 3.0), which one is more basic?

Draw the structure of peroxymonosulphuric acid. 

What are enzymes?

Why is it necessary to add \[\ce{H2SO4}\] while preparing the solution of \[\ce{CuSO4}\]?

Answer the following in one sentence:

Why is it necessary to add \[\ce{H2SO4}\] while preparing the solution of \[\ce{CuSO4}\]?

Answer the following in one sentence:

Why is it necessary to add \[\ce{H2 SO4}\] while preparing the solution of \[\ce{CuSO4}\]?

Why is it necessary to add \[\ce{H2SO4}\] while preparing the solution of \[\ce{CuSO4}\]?

Answer the following in one sentence:

Why is it necessary to add H₂SO₄ while preparing the solution of CuSO₄?

The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.

Answer the following in one sentence:

Why is it necessary to add \[\ce{H2SO4}\] while preparing the solution of \[\ce{CuSO4}\]?

Answer the following in one sentence:

Why is it necessary to add \[\ce{H2SO4}\] while preparing the solution of \[\ce{CuSO4}\]?

How is enthalpy of sublimation related to enthalpy of fusion and enthalpy of vaporization?

Explain the mechanism of esterification

Define the Enthalpy of fusion

Define the Enthalpy of atomization.

Draw structure of DDT.

Draw structure of DDT.

Define ebullioscopic constant.

If the enthalpy of vaporisation of water at 100^oC is 186.5 J.mol^-1, the entropy of vaporization will be_____________ .

(a) 4.0 J . K^-1. mol-¹                                               

(b) 3.0 J . K^-l.  mol^-1

(c) 1.5 J - K^-1. mol-¹                                             

(d) 0.5 J . K^-l. mol^-1

Which of the following is polyamide ?

(a) Teflon

(b) Nylon  6,6

(c) Terylene

(d) Bakelite