HSC Science (General) १२ वीं कक्षा - Maharashtra State Board Question Bank Solutions for Chemistry

What are elastomers? 

Distinguish between thermoplastic polymers and thermosetting polymers.

What is the action of the following on lanthanoids?
a. water
b. Sulphur, heat
c. nitrogen, heat

Molecular solids are ______.

How are the crystalline solids classified?

Answer the following in one or two sentences.

A solid is hard, brittle and electrically nonconductor. Its melt conducts electricity. What type of solid is it?

Answer the following in brief.

Distinguish between ionic solids and molecular solids

Cryoscopic constant depends on ______.

Answer in brief.

What are intensive properties? Explain why density is an intensive property.

Define the degree of dissociation.

Answer the following :

Derive the relationship between the degree of dissociation and dissociation constant in weak electrolytes.

Choose the most correct option.

The order of the reaction for which the units of the rate constant are mol dm^-3 s^-1 is _______.

Choose the most correct option.

The rate constant for the reaction \[\ce{2N2O5_{(g)} -> 2N2O4_{(g)} + O2_{(g)}}\] is `4.98 xx 10^-4 "s"^-1`. The order of reaction is _____________.

The time required for 90% completion of a certain first-order reaction is t. The time required for 99.9% completion will be _________.

Choose the most correct option.

Slope of the graph ln[A]_t versus t for first-order reaction is _________.

What is the half life of a first order reaction if time required to decrease concentration of reactant from 0.8 M to 0.2 M is 12 h?

Choose the most correct option.

The reaction, \[\ce{3ClO- -> ClO^-3 + 2Cl-}\] occurs in two steps, 

(i) \[\ce{2ClO- -> ClO^-2}\]

(ii) \[\ce{ClO^-2 + ClO- -> ClO^-_3 + Cl-}\] 

The reaction intermediate is _______.

The elementary reaction \[\ce{O3_{(g)} + O_{(g)} -> 2O2_{(g)}}\] is ______.

Choose the most correct option.

Rate law for the reaction, \[\ce{2NO + Cl2 -> 2NOCl}\] is rate = k[NO₂]²[Cl₂]. Thus of k would increase with _____________.

Choose the most correct option.

For an endothermic reaction, X ⇌ Y. If E_f is the activation energy of the forward reaction and E_r that for the reverse reaction, which of the following is correct?