Chemistry
Element A has 2 electrons in its M shell. Element B has atomic number 7.
(a) Write equations to show how A and B form ions.
(b) If B is a diatomic gas, write the equation for the direct combination of A and B to form a compound.
(c) If the compound formed between A and B is melted and an electric current is passed through the molten compound, the element A will be obtained at the …………. and B at the ………… of the electrolytic cell.
Answer
A has two electrons in M shell i.e., A has valency 2 (metal), and the electronic configuration of B(7) is 2, 5 i.e., B has valency 3 (non-metal).
(a) A ⟶ A2+ + 2e-
B + 3e- ⟶ B3-
(b) 3A + B2 ⟶ A3B2
(c) Element A will be obtained at the Cathode and B at the Anode of the electrolytic cell.
Reason — As A is a cation, so it is attracted towards cathode as cathode is negatively charged. B is an anion so it is attracted towards anode as anode is positively charged.
Related Questions
For each compound mentioned above give the formulae of ions formed in aqueous solution.
An element M burns in oxygen to form an ionic bond MO. Write the formula of the compounds formed if this element is made to combine with chlorine and sulphur separately.
Element M forms a chloride with the formula MCl2 which is a solid with high melting point. M would most likely be in the group in which ………….. is placed.
(a) Na
(b) Mg
(c) Al
(d) SiComplete the following
Sodium Phosphorus Carbon Formula of chloride Nature of bonding Physical state of chloride