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

The substance ‘X’, when dissolved in solvent water gave molar mass corresponding to the molecular formula ‘X3’. The van’t Hoff factor (i) is _______.

(A) 3

(B) 0.33

(C) 1.3

(D) 1

What is natural rubber?

(A) Cis-1,4-polyisoprene

(B) Neoprene

(C) Trans-1,4-polyisoprene

(D) Butyl rubber

What is the value of for the following reaction at 298 K -

6CO₂+ 6H₂0_(l) → C6H₁₂0_6(s) ⁺ 60_2(g),

Given that: ΔG° = 2879 kj mol^-1, AS = -210 JK^-1 mol^-1.

State and explain Hess’s law of constant heat summation.

With the help of the equation ΔG° = - nFE^o_cell. Explain that cell potential is an intensive property.

Define van’t Hoff factor.

A unit cell of iron crystal has edge length 288 pm and density 7.86 g.cm^-3. Find the number of atoms per unit cell and type of the crystal lattice.

Given : Molar mass of iron = 56 g.mol^-1; Avogadro's number N_A = 6.022 x 10²³.

Mohr’s Salt is -

(a) Ferrous ammonium sulphate

(b) Ferrous sulphate

(c) Ammonium sulphate

(d) Ferric sulphate

How many atoms constitute one unit cell of a face-centered cubic crystal?

Gold occurs as face centred cube and has a density of 19.30 kg dm^-3. Calculate atomic radius of gold. (Molar mass of Au = 197)

What are hormones?

Define complex lipids

Face centred cubic crystal lattice of copper has density of 8.966 g.cm^-3. Calculate the volume of the unit cell. Given molar mass of copper is 63.5 g mol^-1 and Avogadro number N_A is 6.022 x 10²³ mol^-1

Write a note on the self oxidation-reduction reaction of an aldehyde with a suitable example.

Write names and chemical formulae of monomers used in preparing Buna-S.

Mention 'two' functions of lipids

An element crystallises in a b.c.c lattice with cell edge of 500 pm. The density of the element is 7.5g cm^-3. How many atoms are present in 300 g of the element?

Following reactions occur at cathode during the electrolysis of aqueous silver chloride solution :

`Ag^+(aq)+e^(-)rarrAg(s)" ""      ""       "E^@=+0.80V`

`H^+(aq)+e^(-)rarr1/2H_2(g)" "" "" " E^@=0.00V`

On the basis of their standard reduction electrode potential (E°) values, which reaction is feasible at the cathode and why ?

3.9 g of benzoic acid dissolved in 49 g of benzene shows a depression in freezing point of 1.62 K. Calculate the van't Hoff factor and predict the nature of solute (associated or dissociated).

(Given : Molar mass of benzoic acid = 122 g mol⁻¹, K_f for benzene = 4.9 K kg mol⁻¹)

An element with molar mass 27 g mol⁻¹ forms a cubic unit cell with edge length 4.05 ✕ 10⁻⁸ cm. If its density is 2.7 g cm⁻³, what is the nature of the cubic unit cell?