A mixture 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 dа ta:

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