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

One mole of a gas expands by 3L against a constant pressure of 3 atmosphere. Calculate the work done in -

(a) L.atmosphere

(b) Joules

(c) Calories

Calculate the amount of CaCl₂ (van't Hoff factor i = 2.47) dissolved in 2.5 L solution so that its osmotic pressure at 300K is 0.75 atmosphere.

Given : Molar mass of CaCl₂ is 111g mol^-1

R=0.082 L.atm K^-1mol^-1

Describe anomalous behaviour of fluorine with the other elements of group 17 wilh reference to :

(a) Hydrogen bonding

(b) Oxidation state

(c) Polyhalide ions

Write balanced chemical equations for action of potassium permanganate on: Hydrogen

Identify the weakest base amongst the following :

(a) p- methoxyaniline

(b) o-toluidine

(c) benzene - 1, 4 - diamine

(d) 4 - aminobenzoic acid

Bakelite is the polymer of:

(a) Benzaldchyde and phenol

(b) Acetaldehyde and phenol

(c) Formaldehyde and phenol

(d) Formaldehyde and benzyl alcohol

Define electrochemical cell

Why does the cell potential of mercury cell remain constant throughout its life?

An element with density 10 g cm⁻³ forms a cubic unit cell with edge length of 3 × 10⁻⁸ cm. What is the nature of the cubic unit cell if the atomic mass of the element is 81 g mol⁻¹?

The rate constant of a first order reaction increases from 4 × 10⁻² to 8 × 10⁻² when the temperature changes from 27°C to 37°C. Calculate the energy of activation (Ea). (log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)

From the given cells:

Lead storage cell, Mercury cell, Fuel cell and Dry cell

Answer the following:

(i) Which cell is used in hearing aids?

(ii) Which cell was used in Apollo Space Programme?

(iii) Which cell is used in automobiles and inverters?

(iv) Which cell does not have long life?

An element crystallizes in a f.c.c. lattice with a cell edge of 250 pm. Calculate the density if 300 g of this element contains 2 × 10²⁴ atoms. 

The rate constant for the first-order decomposition of H₂O₂ is given by the following equation:

`logk=14.2-(1.0xx10^4)/TK`

Calculate E_a for this reaction and rate constant k if its half-life period be 200 minutes.

(Given: R = 8.314 JK^–1 mol^–1)

The rate constant of a first order reaction increases from 2 × 10⁻² to 4 × 10⁻² when the temperature changes from 300 K to 310 K. Calculate the energy of activation (E_a).

(log 2 = 0.301, log 3 = 0.4771, log 4 = 0.6021)

What type of battery is mercury cell? Why is it more advantageous than dry cell?

An element with density 2.8 g cm^–3 forms a f.c.c. unit cell with edge length 4 x 10^–8 cm. Calculate the molar mass of the element.

(Given : N_A = 6.022 x 10²³ mol ^–1)

Name the type of cell which was used in Apollo space programme for providing electrical power.

A solution of glucose (molar mass = 180 g mol^–1) in water is labelled as 10% (by mass). What would be the molality and molarity of the solution ? (Density of solution = 1.2 g mL^–1)

Define terms: Fuel cell

Define the following terms: Secondary batteries