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

The half life period of a radioactive element is 140 days. After 560 days, 1 g of element will be reduced to

After 2 hours, a radioactive substance becomes `(1/16)^"th"` of original amount. Then the half life ( in min) is

Define half life of a reaction.

Show that for a first order reaction half life is independent of initial concentration.

The rate constant for a first order reaction is 1.54 × 10⁻³ s⁻¹. Calculate its half life time.

The half life of the homogeneous gaseous reaction \[\ce{SO2Cl2 -> SO2 + Cl2}\] which obeys first order kinetics is 8.0 minutes. How long will it take for the concentration of SO₂Cl₂ to be reduced to 1% of the initial value?

Which will make basic buffer?

The dissociation constant of a weak acid is 1 × 10⁻³. In order to prepare a buffer solution with a pH = 4, the `(["Acid"])/(["Salt"])` ratio should be ____________.

The hydrogen ion concentration of a buffer solution consisting of a weak acid and its salts is given by ____________.

K_sp of Al(OH)₃ is 1 × 10⁻¹⁵ M. At what pH does 1.0 × 10⁻³ M Al³⁺ precipitate on the addition of buffer of NH₄Cl and NH₄OH solution?

Addition of Alum purifies water. Why?

Explain briefly the collision theory of bimolecular reactions.

Which of the following relation is correct for degree of hydrolysis of ammonium acetate?

Dissociation constant of NH₄OH is 1.8 × 10⁻⁵ the hydrolysis constant of NH₄Cl would be ____________.

Calculate the extent of hydrolysis and the pH of 0.1 M ammonium acetate Given that K_a = K_b = 1.8 × 10⁻⁵

Derive an expression for the hydrolysis constant and degree of hydrolysis of salt of strong acid and weak base.

Will a precipitate be formed when 0.150 L of 0.1 M Pb(NO₃)₂ and 0.100 L of 0.2 M NaCl are mixed? K_sp (PbCl₂) = 1.2 × 10⁻⁵.

Among the following graphs showing the variation of rate constant with temperature (T) for a reaction, the one that exhibits Arrhenius behavior over the entire temperature range is

Write Arrhenius equation and explains the terms involved.

The addition of a catalyst during a chemical reaction alters which of the following quantities?