HSC Science (Computer Science) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions for Chemistry

Identify the strongest acid amongst the followings:

1. Chloroacetic acid          
2. Acetic acid
3. Trichloroacetic acid
4. Dichloroaceticacid

Write a note on Friedel Craft’s acylation.

Explain, why are boiling points of carboxylic acids higher than corresponding alcohols

A solution of glucose in water is labelled as 10% (W/W).

Calculate:

a. Molality

b. Molarity of the solution.

[Given: Density of solution is 1.20 g mL^-1 and molar mass of glucose is 180 g mol^-1 ]

Write ‘four’ uses of hydrochloric acid.

What is the molecular formula of chromyl chloride?

(A) CrO₂Cl₂

(B) CrOCl₂

(C) CrCl₃

(D) Cr₂OCl₂

A solution containing 0.73 g of camphor (molar mass 152 g . mol^-1) in 36.8 g of acetone (boiling point 56.3°C) boils at 56.55°C. A solution of 0.564 g of unknown compound in the same weight of acetone boils at 56.46^oC. Calculate the molar mass of the unknown compound.

What is the action of acidified potassium dichromate on - SO₂

Draw structure of dichromate ion

Classify the following ligands into monodentate and polydentate —

1. Ammonia
2. Carbon monoxide
3. Ethylene diamine
4. Ethylene diamine tetra acetate ion

Write the structure and IUPAC names of all the metamers represented by formula C₄H₁₀

Write any ‘two’ uses of terylene.

Write the reactions involved in the preparation of  PVC

(b) Rate constant ‘k’ of a reaction varies with temperature ‘T’ according to the equation:

`logk=logA-E_a/2.303R(1/T)`

Where E_a is the activation energy. When a graph is plotted for `logk Vs. 1/T` a straight line with a slope of −4250 K is obtained. Calculate ‘E_a’ for the reaction.(R = 8.314 JK⁻¹ mol⁻¹)

Write cell reaction in lead storage battery during discharge.

Calculate the mole fraction and molality of HNO₃ in solution contaning 12.2%HNO₃ (Given atomic mases:H=1, N=13,O=16)

Consider the reaction

`3I_((aq))^-) +S_2O_8^(2-)->I_(3(aq))^-) + 2S_2O_4^(2-)`

At particular time t, `(d[SO_4^(2-)])/dt=2.2xx10^(-2)"M/s"`

What are the values of the following at the same time?

a. `-(d[I^-])/dt`

b. `-(d[S_2O_8^(2-)])/dt`

c. `-(d[I_3^-])/dt`

300 M mol of perfect gas occupies 13 L at 320 K. Calculate the work done in joules when the gas expands-

(a) isothermally against a Constant external pressure of 0.20atm.

(b) isothermal and reversible process.

(c) into vaccum until the volume of gas is increased by 3L (R=8.314J mol^-1 K^-1)

Write the chemical reaction to prepare novolac polymer.

What is the action of bromine in alkaline medium on

i. CH₃CH₂NO₂

ii.