27 October, 13:57

# A solid mixture consists of 44.2g of KNO3 (potassium nitrate) and 7.8g of K2SO4 (potassium sulfate). The mixture is added to 130. g of water. If the solution described in the introduction is cooled to 0 ∘C, what mass of KNO3 should crystallize? (Assume KNO3 has a solubility of 14 g solute / 100 g water

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1. 27 October, 14:18
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26 g left undisolved which gives you the amount that would crystallize

Explanation:

Step 1: Data given

A solid mixture consists of 44.2g of KNO3 (potassium nitrate) and 7.8g of K2SO4 (potassium sulfate).

The mixture is added to 130. g of water

KNO3 has a solubility of 14 g solute / 100 g water

Step 2: Calculate mass of KNO3 in 130 grams of water

X g of KNO3 / 130 g water = 14 g of KNO3 / 100 g water

X = 14*1300/100 = 18.2

X = 18.2 g (this is the amount of solute that dissolves at 0 degrees C in 130 g water)

Step 3: Calculate amount KNO3 that will crystallize

Of the 44.2g of KNO3 in 130 g of water at 0 degrees celsiusonly 18.2 can dissolve, this means:

44.2g - 18.2g = 26 g left undisolved which gives you the amount that would crystallize