Science (English Medium) कक्षा ११ - CBSE Question Bank Solutions for Chemistry

Elements \[\ce{X, Y}\] and \[\ce{Z}\] have 4, 5 and 7 valence electrons respectively. Write the molecular formula of the compounds formed by these elements individually with hydrogen.

Elements \[\ce{X, Y}\] and \[\ce{Z}\] have 4, 5 and 7 valence electrons respectively. Which of these compounds will have the highest dipole moment?

Which of the following figures does not represent 1 mole of dioxygen gas at STP?

(i) 16 grams of gas

(ii) 22.7 litres of gas

(iii) 6.022 × 10²³ dioxygen molecules

(iv) 11.2 litres of gas

What will be the molar volume of nitrogen and argon at 273.15 K and 1 atm?

\[\ce{PCl5, PCl3 and Cl2}\] are at equilibrium at 500 K in a closed container and their concentrations are 0.8 × 10^–3 mol L^–1, 1.2 × 10^–3 mol L^–1 and 1.2 × 10^–3 mol L^–1 respectively. The value of Kc for the reaction \[\ce{PCl5 (g) ⇌ PCl3 (g) + Cl2 (g)}\] will be ______.

\[\ce{pH}\] of a solution of a strong acid is 5.0. What will be the \[\ce{pH}\] of the solution obtained after diluting the given solution a 100 times?

Calculate the \[\ce{pH}\] of a solution formed by mixing equal volumes of two solutions A and B of a strong acid having \[\ce{pH}\] = 6 and \[\ce{pH}\] = 4 respectively.

Match the following graphical variation with their description

A	B
(i)	(a) Variation in product concentration with time
(ii)	(b) Reaction at equilibrium
(iii)	(c) Variation in reactant concentration with time

The oxide that gives \[\ce{H2O2}\] on treatment with dilute \[\ce{H2SO4}\] is ______.

When sodium peroxide is treated with dilute sulphuric acid, we get ______.

Which of the following ions will cause hardness in water sample?

Which of the following compounds is used for water softening?

Hardness of water may be temporary or permanent. Permanent hardness is due to the presence of:

(i) Chlorides of \[\ce{Ca}\] and \[\ce{Mg}\] in water.

(ii) Sulphates of \[\ce{Ca}\] and \[\ce{Mg}\] in water.

(iii) Hydrogen carbonates of \[\ce{Ca}\] and \[\ce{Mg}\] in water.

(iv) Carbonates of alkali metals in water.

Complete the following equations:

\[\ce{PbS (s) + H2O2 (aq) ->}\]

Complete the following equations:

\[\ce{CO (g) + 2H2 (g) ->[Cobalt][Catalyst]}\]

Discuss briefly de-mineralisation of water by ion exchange resin.

Why is the Ionisation enthalpy of hydrogen higher than that of sodium?

Match the items in Column I with the relevant item in Column II.

Assertion (A): Permanent hardness of water is removed by treatment with washing soda.

Reason (R): Washing soda reacts with soluble magnesium and calcium sulphate to form insoluble carbonates.

If a trivalent atom replaces a few silicon atoms in three-dimensional network of silicon dioxide, what would be the type of charge on overall structure?