Question

A 41-g sample of potassium completely reacts with chlorine to form 78 g of potassium chloride. How many grams of chlorine must have reacted?

Answer 1

37.275g must react

Step-by-step explanation:

Step 1: Balance the reaction

The reaction is as follow:

2 K + Cl2---------> 2KCl

This means that for 2 moles K we have 1 mole Cl2 ( and 2 moles KCl)

Step 2: Calculate moles

Moles of potassium: moles = mass / Molar mass

Moles of potassium = 41g / 39.1g/mol

Moles of potassium = 1.05 moles

for each 2 moles potassium we have 1 mole Cl2 ( and 2 moles KCl)

Moles of Chlorine : 1.05 / 2 = 0.525 moles ( and 1.05 moles of KCl)

Step 3: Calculate mass of chlorine

mass chlorine = moles x Molar mass = 0.525 x 35.5 x 2

= 37.275g Chlorine