Question

Two substances X and Y are dissolved in water under suitable conditions. X is a gas while Y is a solid under normal conditions. Solution of Y is found to conduct electricity but not X. Based on the conclusion, identify the nature of the bond present in X and Y with appropriate reasons as given below.
Arrange the step given below in a sequence:
a. Y is a solid at room temperature and its aqueous solution conducts electricity. This shows that it is an ionic compound.
b. X on dissociation in water does not conduct electricity and is a gas at room temperature. Hence, it should be a nonpolar covalent molecule.
c Aqueous solutions of both ionic compounds and polar covalent compounds conduct electricity because of the presence of free ions.
d. All ionic compounds are solids and more of the nonpolar covalent molecules are gases or solids at room temperature. Polar covalent compounds are liquids or gases.
A) c d b a
B) a d c b
C) a c b d
D) c a b d

Answer 1

Hint: Ionic compounds in solid state do not conduct electricity as there are no free mobile ions but the aqueous solution of ionic compounds conduct electricity. On the other hand, covalent compounds do not have electrical conductivity, either in the pure form or in the aqueous state.

Complete step by step answer:
To solve the problem, we first need to understand the term covalent and ionic compounds.
Compounds can be defined as a substance, which contains two or more different elements. They have distinct chemical structures that are characterized by a fixed ratio of the atoms held together by chemical bonds. We will learn about the two classes of compounds based on the type of bond that hold the atoms together: ionic and covalent bond.
Ionic bonds are formed from the strong electrostatic interactions between the ions, which result in the higher electrical conductivity and melting point as compared to covalent compounds. The sharing of electrons between the atoms forms covalent bonds. Due to sharing, they exhibit characteristic physical properties, which include lower electrical conductivity and melting points as compared to the ionic compounds.
Based on the conclusion, the nature of bond present in X and Y with appropriate reasons as given below in a sequence:
-Aqueous solutions of both ionic compounds and polar covalent compounds conduct electricity because of the presence of free ions.
-All ionic compounds are solids and more of the nonpolar covalent molecules are gases or solids at room temperature. Polar covalent compounds are liquids or gases.
-X on dissociation in water does not conduct electricity and is a gas at room temperature. Hence, it should be a nonpolar covalent molecule.
- Y is a solid at room temperature and its aqueous solution conducts electricity. This shows that it is an ionic compound.
So, the correct answer is “Option A”.

Note:
Some important points need to be remembered that covalent compounds at normal atmospheric pressure room temperature exist as solid, liquid, or gas, whereas ionic compounds can exist only as a solid. Due to the stable crystalline structures, ionic compounds have higher boiling and melting points as compared to the covalent compounds.