Amixture of nacl and nabr has a mass of 2.07 g and is found to contain 0.78 g of na. what is the mass of nabr in the mixture?

Mass of NaBr =  0.62 g

Explanation:

Given data:

Mass of NaCl and NaBr = 2.07 g

Mass of sodium = 0.78 g

Mass of NaBr = ?

Solution:

Consider the mass of NaCl is X then the mass of NaBr would be

Mass of NaBr = Total mass - mass of NaCl

Mass of NaBr =         2.07 - X

Mass of sodium in NaCl  = 23 / 58.4 × X

Mass of sodium in NaCl  =  0.394X

Mass of sodium in NaBr  =  23/ 102.9 × (2.07 - X)

Mass of sodium in NaBr  = 0.224 (2.07 - X)

Mass of sodium in NaBr  = 0.464 - 0.224 X

The mass of sodium is given i.e. 0.71 g.

0.394X  +  0.464 - 0.224 X = 0.71

0.394X  - 0.224 X = 0.71 -  0.464

0.17 X = 0.246

X = 0.246/ 0.17

X = 1.45 g

X is the mass of NaCl that's why

Mass of NaBr = Total mass - mass of NaCl

Mass of NaBr =   2.07 g -  1.45 g

Mass of NaBr =    0.62 g