HSC Science कक्षा १२ - Tamil Nadu Board of Secondary Education Question Bank Solutions for Chemistry

The pH of an aqueous solution is Zero. The solution is ____________.

The concentration of hydroxide ion in a water sample is found to be 2.5 × 10⁻⁶ M. Identify the nature of the solution.

A lab assistant prepared a solution by adding a calculated quantity of HCl gas at 25°C to get a solution with [H₃O⁺]= 4 × 10⁻⁵ M. Is the solution neutral (or) acidic (or) basic.

Calculate the pH of 0.04 M HNO₃ solution.

Calculate the pH of 1.5 × 10⁻³ M solution of Ba(OH)₂.

50 ml of 0.05 M HNO₃ is added to 50 ml of 0.025 M KOH. Calculate the pH of the resultant solution.

The K_a value for HCN is 10⁻⁹. What is the pH of 0.4 M HCN solution?

Consider the following half cell reactions:

\[\ce{Mn^{2+} + 2e^- -> Mn}\] E⁰ = –1.18 V

\[\ce{Mn^{2+} -> Mn^{2+} + e^-}\] E⁰ = –1.51 V

The E⁰ for the reaction \[\ce{3Mn^{2+} -> Mn + 2Mn^{3+}}\], and the possibility of the forward reaction are respectively.

The button cell used in watches functions as follows.

\[\ce{Zn_{(s)} + Ag2O_{(s)} + H2O_{(l)} ⇌ 2Ag_{(s)} + Zn^{2+}_{( aq)} + 2OH^-_{( aq)}}\] the half cell potentials are \[\ce{Ag2O_{(s)} + H2O_{(l)} + 2e^- -> 2Ag_{(s)} + 2OH^-_{( aq)}}\] E⁰ = 0.34 V The cell potential will be

During electrolysis of molten sodium chloride, the time required to produce 0.1 mole of chlorine gas using a current of 3A is ___________.

The number of electrons delivered at the cathode during electrolysis by a current of 1A in 60 seconds is ____________.
(charge of electron = 1.6 × 10⁻¹⁹ C)

While charging lead storage battery

Among the following cells

I) Leclanche cell

II) Nickel – Cadmium cell

III) Lead storage battery

IV) Mercury cell

Primary cells are:

In \[\ce{H2 - O2}\] fuel cell the reaction occurs at cathode is:

For the cell reaction

\[\ce{2Fe^{3+}_{( aq)} + 2l^-_{( aq)} -> 2Fe^{2+}_{( aq)} + l2_{( aq)}}\]

\[\ce{E^0_{cell}}\] = at 298 K. The standard Gibbs energy (∆G°) of the cell reactions is:

State Faraday’s Laws of electrolysis.

A current of 1.608A is passed through 250 mL of 0.5 M solution of copper sulphate for 50 minutes. Calculate the strength of Cu²⁺ after electrolysis assuming volume to be constant and the current efficiency is 100%.

Calculate the standard emf of the cell: \[\ce{Cd|Cd^{2+}||Cu^{2+}|Cu}\] and determine the cell reaction. The standard reduction potentials of Cu²⁺|Cu and Cd²⁺|Cd are 0.34 V and −0.40 volts respectively. Predict the feasibility of the cell reaction.

In fuel cell H₂ and O₂ react to produce electricity. In the process, H₂ gas is oxidised at the anode and O₂ at cathode. If 44.8 litre of H₂ at 25°C and 1 atm pressure reacts in 10 minutes, what is average current produced? If the entire current is used for electro deposition of Cu from Cu²⁺, how many grams of deposited?

The same amount of electricity was passed through two separate electrolytic cells containing solutions of nickel nitrate and chromium nitrate respectively. If 2.935 g of Ni was deposited in the first cell. The amount of Cr deposited in the another cell?
Given: molar mass of Nickel and chromium are 58.74 and 52 gm⁻¹ respectively.