Question

An element $X$ (Atomic number $12$) reacts with another element $Y$ (atomic number $17$) to form a compound $Z$. Which of the following statements are true regarding this compound?
I. Molecular formula of $Z$ is $X{Y}_2$.
II. It is soluble in water.
III. $X$ and $Y$ are joined by sharing of electrons.
IV. It would conduct electricity in the molten state.

• A. (II) and (III)
• B. (I) and (III)
• C. (I), (III) and (IV)
• D. (I), (II) and (IV)

Answer 1

The correct option is D (I), (II) and (IV)

An element X (atomic number 12) is $Mg$ and another element Y (atomic number 17) is $Cl$. and the compound formed is $MgC{l}_2$ [Z].

$Mg+C{l}_2\to MgC{l}_2$

I. Molecular formula of Z is $MgC{l}_2$ which is $X{Y}_2$ type.

II. $MgC{l}_2$ is soluble in water because it is an ionic solid so it will dissolve only in a polar solvent like water.

III. $Mg$ and $C{l}_2$ are joined by the transfer of electrons from magnesium to chlorine.

IV. $MgC{l}_2$ conduct electricity in the molten state because it is an ionic compound means it is made of ions and when it is melted the ions move apart and become charge carriers,