Science (English Medium) Class 11 - CBSE Question Bank Solutions

Which hybrid orbitals are used by carbon atoms in the following molecules?

CH₃–CH₃

For the reaction at 298 K,

\[\ce{2A + B → C}\]

ΔH = 400 kJ mol^-1 and ΔS = 0.2 kJ K^-1 mol^-1

At what temperature will the reaction become spontaneous considering ΔH and ΔS to be constant over the temperature range?

For the reaction

\[\ce{2A_{(g)} + B_{(g)} → 2D_{(g)}}\]

ΔU^θ = –10.5 kJ and ΔS^θ= –44.1 JK^–1.

Calculate ΔG^θ for the reaction, and predict whether the reaction may occur spontaneously.

Why is benzene extra ordinarily stable though it contains three double bonds?

Write down the products of ozonolysis of 1, 2-dimethylbenzene (o-xylene). How does the result support Kekulé structure for benzene?

Give a brief description of the principle of the following technique taking an example.

Distillation 

What is the difference between distillation, distillation under reduced pressure and steam distillation ?

What will be the conjugate bases for the following Bronsted acids:

HF, H₂SO₄ and \[\ce{HCO^-_3}\]? 

Which hybrid orbitals are used by carbon atoms in the following molecules?

CH₃–CH=CH₂

Which hybrid orbitals are used by carbon atoms in the following molecules?

CH₃-CH₂-OH

Which hybrid orbitals are used by carbon atoms in the following molecules?

CH₃-CHO

Which hybrid orbitals are used by carbon atoms in the following molecules?

CH₃COOH

What will be the molarity of a solution, which contains 5.85 g of NaCl(s) per 500 mL?

If 500 mL of a 5 M solution is diluted to 1500 mL, what will be the molarity of the solution obtained?

If the concentration of glucose \[\ce{(C6H12O6)}\] in blood is 0.9 g L^–1, what will be the molarity of glucose in blood?

What will be the molality of the solution containing 18.25 g of \[\ce{HCl}\] gas in 500 g of water?

Sulphuric acid reacts with sodium hydroxide as follows:

\[\ce{H2SO4 + 2NaOH -> Na2SO4 + 2H2O}\]

When 1 L of 0.1 M sulphuric acid solution is allowed to react with 1 L of 0.1 M sodium hydroxide solution, the amount of sodium sulphate formed and its molarity in the solution obtained is:

(i) 0.1 mol L^–1

(ii) 7.10 g

(iii) 0.025 mol L^–1

(iv) 3.55 g

Which of the following solutions have the same concentration?

(i) \[\ce{20 g of NaOH in 200 mL of solution}\]

(ii) \[\ce{0.5 mol of KCl in 200 mL of solution}\]

(iii) \[\ce{40 g of NaOH in 100 mL of solution}\]

(iv) \[\ce{20 g of KOH in 200 mL of solution}\]

Which of the following terms are unitless?

(i) Molality

(ii) Molarity

(iii) Mole fraction

(iv) Mass percent

What is the difference between molality and molarity?