Question

Chemical Make up of One of Chloroform

Element	Number of Moles	Mass per Mole (grams)
Carbon	1	12.011
Hydrogen	1	1.008
Chlorine	3	35.453

A chemical solvent is a substance that dissolves another to form a solution. For example, water is a solvent for sugar. Unfortunately, many chemical solvents are hazardous to the environment. One eco-friendly chemical solvent is chloroform, also known as trichloromethane ($CH{Cl}_3$). The table above shows the chemical makeup of one mole of chloroform.
If a chemist starts with $1,000$ grams of chloroform and uses $522.5$ grams, how many moles of chlorine are left?

Answer 1

$CHC{l}_3\to C+H+3Cl$

Chloroform used=$522.5gm$

Now, number of moles $=\frac{weight}{molecularweight}$

Molecular weight of Chloroform ($CHC{l}_3$)$=119.5g/mol$

Moles of $CHC{l}_3$ used=$4.376$

Moles of Chlorine formed =$4.376moles$

Now considering chlorine left=$1000-522.5=477.5$

Moles of $CHC{l}_3=3.999\approx 4$

Hence, moles of Chlorine left=$4$