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

Explain the cause of Lanthanoids contraction.

How are ethylamine and ethyl methyl amine distinguished by using nitrous acid?

What are isotonic solutions? Explain with one example.

What are antacids? 

Derive van’t Hoff general solution equation.

Write any ‘four points’ of difference between fluorine and other halogens.

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 ______.

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 _______.