Question

A compound consists of 47.8% zinc and 52.2% chlorine by mass. The empirical formula is Zn${}_x$Cl${}_y$ where x and y can have the values:

• A. 1 and 1
• B. 1 and 2
• C. 2 and 1
• D. 2 and 3 respectively

Answer 1

The correct option is B 1 and 2

For finding empirical formula, follow these steps:

Step 1: Convert percentage into mass (example: $70$% is $70g$)

Step 2: Find number of moles of each compound

Step 3: Find their ratios

Here, mass of $Zn=47.8g$

So, moles of $Zn=\frac{47.8g}{65.5g}=0.72$

Also, mass of $Cl=52.2g$

So, moles of $Zn=\frac{52.2g}{35.5g}=1.47$

Ratios of moles of both $Zn:Cl=0.72:1.47=1:2$

$Z{n}_{x}C{l}_y=x=1;y=2$