Answer: The molecular formula will be [tex]H_{16}NOCl[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of H = 5.80 g
Mass of N = 20.16 g
Mass of O = 23.02 g
Mass of Cl = 51.02 g
Step 1 : convert given masses into moles.
Moles of H =[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{5.80g}{1g/mole}=5.80moles[/tex]
Moles of N =[tex]\frac{\text{ given mass of N}}{\text{ molar mass of N}}= \frac{20.16g}{14g/mole}=1.44moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{23.02g}{16g/mole}=1.44moles[/tex]
Moles of Cl =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{51.02g}{35.5g/mole}=1.44moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For H = [tex]\frac{5.80}{1.44}=4[/tex]
For N = [tex]\frac{1.44}{1.44}=1[/tex]
For O = [tex]\frac{1.44}{1.44}=1[/tex]
For Cl = [tex]\frac{1.44}{1.44}=1[/tex]
The ratio of H: N: O: Cl= 4: 1: 1: 1
Hence the empirical formula is [tex]H_4NOCl[/tex]
The empirical weight of [tex]H_4NOCl[/tex] = 4(1)+1(14)+ 1(16) + 1(35.5)= 69.5 g.
The molecular weight = 278 g/mole
Now we have to calculate the molecular formula.
[tex]n=\frac{\text{Molecular weight }}{\text{Equivalent weight}}=\frac{278}{69.5}=4[/tex]
The molecular formula will be=[tex]4\times H_4NOCl=H_{16}NOCl[/tex]