Science (English Medium) इयत्ता ११ - CBSE Question Bank Solutions

Why does fluorine not show disporportionation reaction?

Write redox couples involved in the reactions given.

\[\ce{Cu + Zn^{2+} ->Cu^{2+} + Zn}\]

Write redox couples involved in the reactions given.

\[\ce{Mg + Fe^{2+} -> Mg^{2+} + Fe}\]

Write redox couples involved in the reactions given.

\[\ce{Br2 + 2Cl- -> Cl2 + 2Br-}\]

Write redox couples involved in the reactions given.

\[\ce{Fe + Cd^{2+} -> Cd + Fe^{2+}}\]

Find out the oxidation number of chlorine in the following compounds and arrange them in increasing order of oxidation number of chlorine.

\[\ce{NaClO4, NaClO3, NaClO, KClO2, Cl2O7, ClO3, Cl2O, NaCl, Cl2 , ClO2}\].

Which oxidation state is not present in any of the above compounds?

Which of the following hydrides is electron-precise hydride?

Which of the following statements about hydrogen are correct?

(i) Hydrogen has three isotopes of which protium is the most common.

(ii) Hydrogen never acts as cation in ionic salts.

(iii) Hydrogen ion, \[\ce{H+}\], exists freely in solution.

(iv) Dihydrogen does not act as a reducing agent.

Which of the following statements is correct?

(i) Elements of group 15 form electron deficient hydrides.

(ii) All elements of group 14 form electron precise hydrides.

(iii) Electron precise hydrides have tetrahedral geometries.

(iv) Electron rich hydrides can act as Lewis acids.

Explain the following:

Gallium has higher ionisation enthalpy than aluminium.

Explain the following:

Aluminium forms [AlF₆]^3– ion but boron does not form [BF₆]^3– ion.

Assertion (A): If aluminium atoms replace a few silicon atoms in three-dimensional network of silicon dioxide, the overall structure acquires a negative charge.

Reason (R): Aluminium is trivalent while silicon is tetravalent.

Account for the following observations:

AlCl₃ is a Lewis acid

Express the following in the scientific notation: 

0.0048

Express the following in the scientific notation:

234,000

Express the following in the scientific notation:

8008

Express the following in the scientific notation:

500.0

Express the following in the scientific notation:

6.0012

If the speed of light is 3.0 ×10⁸ m s^-1, calculate the distance covered by light in 2.00 ns.

Write the general outer electronic configuration of s- block elements.