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

Assertion (A): Significant figures for 0.200 is 3 where as for 200 it is 1.

Reason (R): Zero at the end or right of a number are significant provided they are not on the right side of the decimal point.

Which of the following conclusions could not be derived from Rutherford’s α -particle scattering experiment?

In the modern periodic table, elements are arranged in order of increasing atomic numbers which is related to the electronic configuration. Depending upon the type of orbitals receiving the last electron, the elements in the periodic table have been divided into four blocks, viz, s, p, d and f. The modern periodic table consists of 7 periods and 18 groups. Each period begins with the filling of a new energy shell. In accordance with the Arfbau principle, the seven periods have 2, 8, 8, 18, 18, 32 and 32 elements respectively. The seventh period is still incomplete. To avoid the periodic table being too long, the two series of f-block elements, called lanthanoids and actinoids are placed at the bottom of the main body of the periodic table.

The last element of the p-block in 6^th period is represented by the outermost electronic configuration.

Which of the following sequences contain atomic numbers of only representative elements?

(i) 3, 33, 53, 87

(ii) 2, 10, 22, 36

(iii) 7, 17, 25, 37, 48

(iv) 9, 35, 51, 88

Write four characteristic properties of p-block elements.

p-Block elements form acidic, basic and amphoteric oxides. Explain each property by giving two examples and also write the reactions of these oxides with water.

In \[\ce{PO^{3-}4}\] ion the formal charge on the oxygen atom of P – O bond is ______.

In \[\ce{NO^{-}3}\] ion, the number of bond pairs and lone pairs of electrons on nitrogen atom are ______.

Which of the following species have the same shape?

(i) \[\ce{CO2}\]

(ii) \[\ce{CCl4}\]

(iii) \[\ce{O3}\]

(iv) \[\ce{NO^{-}3}\]

Increase in kinetic energy can overcome intermolecular forces of attraction. How will the viscosity of liquid be affected by the increase in temperature?

Name two intermolecular forces that exist between HF molecules in liquid state.

Viscosity of a liquid arises due to strong intermolecular forces existing between the molecules. Stronger the intermolecular forces, greater is the viscosity. Name the intermolecular forces existing in the following liquids and arrange them in the increasing order of their viscosities. Also give reason for the assigned order in one line.

Water, hexane \[\ce{(CH3CH2CH2CH2CH2CH3), glycerine (CH2OH CH(OH) CH2OH)}\]

Explain the effect of increasing the temperature of a liquid, on intermolecular forces operating between its particles, what will happen to the viscosity of a liquid if its temperature is increased?

Which of the following is not a general characteristic of equilibria involving physical processes?

Metal hydrides are ionic, covalent or molecular in nature. Among \[\ce{LiH, NaH, KH, RbH, CsH}\], the correct order of increasing ionic character is ______.

Only one element of ______ forms hydride.

Which of the following statements are not true for hydrogen?

(i) It exists as diatomic molecule.

(ii) It has one electron in the outermost shell.

(iii) It can lose an electron to form a cation which can freely exist.

(iv) It forms a large number of ionic compounds by losing an electron.

Which of the following statements is correct?

(i) Hydrides of group 13 act as Lewis acids.

(ii) Hydrides of group 14 are electron deficient hydrides.

(iii) Hydrides of group 14 act as Lewis acids.

(iv) Hydrides of group 15 act as Lewis bases.

Which of the following statements is correct?

(i) Metallic hydrides are deficient of hydrogen.

(ii) Metallic hydrides conduct heat and electricity.

(iii) Ionic hydrides do not conduct electricity in solid-state.

(iv) Ionic hydrides are very good conductors of electricity in solid state.

What are metallic/interstitial hydrides? How do they differ from molecular hydrides?