Question

Predict the formula of the stable binary compounds that would be formed by the combination of the following pairs of elements.

(a) Lithium and oxygen (b) Magnesium and nitrogen

(c) Aluminium and iodine (d) Silicon and oxygen

(e) Phosphorus and fluorine (f) Element 71 and fluorine

Answer 1

A. Li2O

B. Mg3N2

C. AlI3

D. SiO2

E. PF3

F. LuF3

Answer 2

Explanation:

A compound formed by combination of two different elements which are present in a fixed ratio by mass are known as binary compounds.

The given compounds will be result in the formation of following compounds.

(a) Lithium and oxygen : Lithium has valency +1 and oxygen has valency -2. So, by cross multiplication method formula of the compound will be $Li_{2}O$.

(b) Magnesium and nitrogen : Magnesium has valency +2 and nitrogen has valency -3. So, by cross multiplication method formula of the compound will be $Mg_{3}N_{2}$.

(c) Aluminium and iodine : Aluminium has valency +3 and iodine has valency -1. So, by cross multiplication method formula of the compound will be $AlI_{3}$.

(d) Silicon and oxygen : Silicon has valency +4 and oxygen has valency -2. So, by cross multiplication method formula of the compound will be $SiO_{2}$.

(e) Phosphorus and fluorine : Phosphorous has valency +3 and oxygen has valency -2. So, by cross multiplication method formula of the compound will be $PF_{3}$.

(f) Element 71 and fluorine : Element 71 is lutetium and its valency is +3. Whereas valency of fluorine is -1. So, by cross multiplication method formula of the compound will be $LuF_{3}$.