Solution, Solute and Solvent Problem 4

Let,
Mass of Water $= xg$
$\Rightarrow$ Mass of sucrose $= (100-x)g$

As the solution is saturated,
Mass of sucrose $=$ Solubility in $xg$ of water

Therefore,
$100-x = \frac{203}{100} x$
$\Rightarrow x = 33g$

Hence,
Mass of Sucrose required $= 100-33 = \boxed{67g}$
Mass of Water required $= \boxed{33g}$

To solve this problem in under 5 seconds, estimate that: 203/100 is approx 2:1.
100 grams at a 2:1 ratio is 66.6 to 33.3

Sucrose / Water = 203 / 100 = 2.03
Sucrose = 2.03 Water
Sucrose + Water = 100
2.03 Water + Water = 100
Water = 100/3.03 = 33g
Sucrose = 67g

Easiest way will be, since 203g sucrose can be dissolved in 100g of water to form a saturated solution, amt of sucrose will always be higher than water to get a saturated solution of sucrose. No calculations will be required since in the options A and C the amount of sucrose is less than the amount of water and in option be amount of sucrose is equal to amount of water. Therefore, these options can be rejected and the correct answer will be D.