Question

1. empirical formula for Cu2o4?

Answer 1

We know that

1) empirical formula of a compound is the representation of a molecules with the elements in simplest mole ratio.

2) the molar mass is the actual proportion of moles of elements present in a molecule

3) there is a simple ratio between the molar mass and empirical mass a molecule

Now let us solve each problem

1) empirical formula of $Cu_{2}O_{4}$ will be $CuO_{2}$

2) empirical formula of $Zn_{3}(NO_{3})_{4}$ will be $Zn_{3}(NO_{3})_{4}$

3) empirical formula of $Ti_{2}S_{2.5}$ will be $Ti_{4}S_{5}$

4) the molecular formula will be :

$Ratio=\frac{molarmass}{empiricalformula}=\frac{112.04}{28.01}=4$

the molecular formula = 4 X empirical formula = 4 X CO = $C_{4}O_{4}$

5) the mole ratio of Cl and Cr is $\frac{1.90}{0.631}=3$

empirical formula will be $CrCl_{3}$