Question

4 salt samples were each dissolved into 200 cm3 of water to determine their solubility. The amount of each salt that dissolved is recorded below: Magnesium chloride: 110 grams Sodium chloride: 76 grams Copper chloride: 139 grams Zinc chloride: 400 grams Order the salts from least soluble to most soluble

A. Copper chloride, sodium chloride, zinc chloride, magnesium chloride
B. Magnesium chloride, zinc chloride, sodium chloride, copper chloride
C. Sodium chloride, magnesium chloride, copper chloride, zinc chloride
D. Magnesium chloride, zinc chloride, copper chloride, sodium chloride

Answer 1

The correct answer is option C.

Step-by-step explanation:

To be able to compare the solubilities in water of different salts you must first use a "common base" to compare them, normally the concept of "grams of salt dissolved in 100 cm3 of water" can be used.

However, in this example, all the solubility data is provided in 200 cm3 of water, which is equivalent to calculating the grams dissolved in 100 cm3 and IT IS NOT NECESSARY TO PERFORM any additional calculation, all the data have a common basis to compare them.

IMPORTANT: "The greater the amount in grams of salt dissolved in water, the greater its solubility in water"

Then you should only order from LOWER to HIGHER amount of grams of salt dissolved in 200 cm3 of water.

Therefore, the least water soluble salt is Sodium chloride (76 grams) and the most water soluble is zinc chloride (400 grams) in this exercise.