Question

2.5gram of sugar is dissolved in 47.5gram of water. calculate its concentration as percent by mass

Answer 1

Concentration as percent by mass will be 5%.
since,
$\frac{2.5}{2.5 + 47.5} \times 100$
will gives 5%

Answer 2

MASS OF SOLUTE=2.5 GRAM
MASS OF SOLVENT=47.5 GRAM
MASS OF SOLUTION= MASS OF SOLUTE + MASS OF SOLVENT
                                    = 50 GRAM

CONCENTRATION OF SOLUTION=MASS OF SOLUTE/MASS SOLUTION X100
                                                        = 2.5/50 X100
                                                        =2.5X2
                                                          = 5 %

CONCENTRATION OF SOLUTION= 5%