contestada

How many grams of chlorine gas are needed to react with 3.5 liters of a 1.7 molar
potassium bromide solution?
Cl2 + 2 KBr - 2 KCl + Br2

Respuesta :

Answer: 211.2 grams

Explanation:

To calculate the number of moles for given molarity, we use the equation:

[tex]\text{Molarity of the solution}=\frac{\text{Moles of solute}}{\text{Volume of solution in L)}}[/tex]     .....(1)

Molarity of [tex]KBr[/tex] solution = 1.7 M

Volume of solution = 3.5 L

Putting values in equation 1, we get:

[tex]1.7M=\frac{\text{Moles of}KBr}{3.5L}\\\\\text{Moles of }KBr=\{1.7mol/L\times 3.5L}=5.95moles[/tex]

The balanced chemical reaction is:

[tex]Cl_2+2KBr\rightarrow 2KCl+Br_2[/tex]

According to stoichiometry:

2 mole of KBr requires = 1 mole of [tex]Cl_2[/tex]

5.95 moles of KBr requires = [tex]\frac{1}{2}\times 5.95=2.975[/tex] moles of [tex]Cl_2[/tex]

Mass of [tex]Cl_2=moles\times {\text {Molar mass}}=2.975mol\times 71g/mol=211.2g[/tex]

Thus 211.2 grams of chlorine gas are needed to react with 3.5 liters of a 1.7 molar potassium bromide solution