Q. 6.98 - An Introduction to General, Organic, and Biological Chemistry

Question

Consider the following Lewis symbols for elements X and Y: 

a. What are the group numbers of X and Y?

b. Will a compound of X and Y be ionic or molecular?

c. What ions would be formed by X and Y?

d. What would be the formula of a compound of X and Y?

e. What would be the formula of a compound of X and sulfur?

f. What would be the formula of a compound of Y and chlorine?

g. Is the compound in part f ionic or molecular?

Step-by-Step Solution

Answer

a. Element X belong to group $2$ while element Y belongs to group $15$.

b. A compound of X and Y will be ionic.

c. The ions formed by X and Y are $X^{2+}$ and $Y^{3-}$.

d. the formula of a compound of X and Y will be $X_3{Y}_2$.

e. The formula of a compound of X and sulfur will be $XS$.

f. The formula of a compound of Y and chlorine will be $YC{l}_3$.

g. The compound in part f is molecular.

Part(a) Step 1: Given information

We have been given Lewis structure of elements X and Y.

We need to find the group numbers to which elements X and Y belong.

Part(a) Step 2: Explanation

Lewis symbols depicts the valence electrons of atoms and ions. Here, element X have $2$ valence electron so it can belong to group $2$ and element Y have valence $5$ electrons so its group number can be $10+5=15$.

Part(b) Step 1: Given information

We have been given Lewis structure of elements X and Y.

We need to find whether the compound of X and Y be ionic or molecular.

Part(b) Step 2: Explanation

Element X can give $2$ electron to attain stable configuration and form $X^{2+}$. Element Y can take up $3$ electrons and form $Y^{3-}$. Hence, the compound formed by them can be ionic.

Part(c) Step 1: Given information

We have been given Lewis structure of elements X and Y.

We need to find the ions would be formed by X and Y.

Part(c) Step 2: Explanation

When an atom gives away electron, it forms a cation and when it takes up electron, it forms an anion. Here,  element  X form a cation $X^{2+}$ and element Y form a anion $Y^{3-}$.

Part(d) Step 1: Given information

We have been given Lewis structure of elements X and Y.

We need to find the formula of a compound of X and Y .

Part(d) Step 2: Explanation

Element  X form a cation $X^{2+}$ and element Y form a anion $Y^{3-}$. The compound formed by them have formula $X_3{Y}_2$.

Part(e) Step 1: Given information

We have been given Lewis structure of elements X and Y.

We need to find the formula of a compound of X and sulfur.

Part(e) Step 2: Explanation

 Element  X form a cation $X^{2+}$ and element sulfur form a anion $S^{2-}$. The compound formed by them have formula $XS$.

Part(f) Step 1: Given information

We have been given Lewis structure of elements X and Y.

We need to find the formula of a compound of Y and chlorine.

Part(f) Step 2: Explanation

Element Y needs $3$ electrons to complete its octet while Chlorine need $1$ electron to attain stable configuration. Hence the compound formed by them can have the formula $YC{l}_3$.

Part(g) Step 1: Given information

We have been given Lewis structure of elements X and Y.

We need to find whether the compound in part f is ionic or molecular.

Part(g) Step 2: Explanation

Since the element Y is belongs to non-metal group, it forms  covalent bond with chlorine. So the compound in part f will be molecular.