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THE TEMPERATURE DEPENDENCE OF THE SOLUBILITY OF A SALT IN WATER The Pre Lab 1. R

ID: 542308 • Letter: T

Question

THE TEMPERATURE DEPENDENCE OF THE SOLUBILITY OF A SALT IN WATER The Pre Lab 1. Referring to the solubility graph for KCIO, given earlier in the experiment, indicate whether at 60 a solution of 20 grams of KClO, in 100 grams of water is supersaturated solutiorn About how much KCIO, would dissolve in 38 grams of water at 70°C? saturated 12.2 2. Data is shown where the saturation temperature has been found for dissolving 6.5 g of solid ammonium chloride (NH&CI;) in various quantities of water. Mass of NHCl used in all trials 6.5g Total ma ofHO used 9.0 g (trial 1) 12.0 g (trial 2) 58 16.0 g (trial 3) 28 Saturation temperature 97 Solution concentration 72 g/100 gH0 41 g/100 g HO a) Complete the data by calculating the solution concentration at 58 °C 804 grams NHC 60 100 g H2O b) Graph the data 20 40 60 80 100 temperature Name three sources of experimental error other than weighing that could be important in this experiment. Explain how each would influence the results. - Th ebreticaenviconmen tal -cbservalianal 3. hsrunentol

Explanation / Answer

Q1.

S = 20/100 = 0.2 g of KClO3/g water

from the solubility of KClO3 = 22 g / 100 g which implies 2.2 g of KClO3 / g of water

therefore,

it must be unsaturated since Sreal < Ssat

in m = 38 g of T = 70°

S at 70° = 30 g / 100 g

30 g of salt = 100 g of water

x g of salt = 38 g of water

x = 38*30/100 = 11.4 g of salt cna be soluble at 70°C and m = 38 g of water