Cl2 + 2KBr -> Br2 + 2KCI
How many grams of Br2 can be produced from 356 g of KBr?
A. 2.99 g Br2
B. 1.50 g Br2
C. 9.10 g Br2
D. 239 g Br2​

Respuesta :

Answer: D. 239 g of [tex]Br_2[/tex]

Explanation:

To calculate the moles :

[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]    

[tex]\text{Moles of} KBr=\frac{356g}{119g/mol}=2.99moles[/tex]

The balanced chemical reaction is:

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

According to stoichiometry :

2 moles of [tex]KBr[/tex] produce =  1 mole of [tex]Br_2[/tex]

Thus 2.99 moles of [tex]KBr[/tex] produce =[tex]\frac{1}{2}\times 2.99=1.495moles[/tex]  of [tex]Br_2[/tex]

Mass of [tex]Br_2=moles\times {\text {Molar mass}}=1.495moles\times 159.8g/mol=239g[/tex]

Thus 239 g of [tex]Br_2[/tex] will be produced from 356 g of KBr.