2 NABr + CA(OH)2 = CABr2 + 2 NAOH How many grams of NaBr are needed to produce 187 grams of CaBr2?

Question

could you please help me answering this question. It is foe eleventh grade.

 

Thank you.

Answer 1

According to the equation, 2 moles of NaBr produce 1 mole of CaBr₂.

 

Molar masses of NaBr and CaBr₂ can be determined using the periodic table.

 

Molar mass of NaBr = 102.9g/mol

 

Molar mass of CaBr₂ = 199.9g/mol

 

This means 2(102.9) = 205.8g NaBr produces 199.9g CaBr₂

 

And x g of NaBr produces 187g CaBr₂

 

Using direct proportions

 

205.8/x = 199.9/187

 

199.9x = 38484.6

 

x = 38484.6/199.9 = 192.5g

 

Answer: 192.5g NaBr is needed.