Question

How many moles of KCIO3 are in 5 g of KClO3?

Answer 1

1. Calculate the molar mass of KClO3: 39.098+ 35.453 + 3(16) = 122.551 g KClO3
2. 5gKClO3 x 1mol KClO3/ 122.551g KClO3 = 0.041mol of KClO3

Answer 2

Molar mass of KClO3

$\\ \tt\hookrightarrow 39+35+3(16)$

$\\ \tt\hookrightarrow 74+48$

$\\ \tt\hookrightarrow 122g/mol$

Now

$\\ \tt\hookrightarrow No\:of\:moles=\dfrac{Given\:mass}{Molar\:mass}$

$\\ \tt\hookrightarrow No\:of\:moles=\dfrac{5}{122}$

$\\ \tt\hookrightarrow No\:of\:moles=0.04mol$