How many grams of #CaCl_2# can dissolve in 200 g of water at 10°C?

1 Answer
May 23, 2017

Answer:

#128"gCaCl"_2# per #200"gH"_2"O"#

Explanation:

You will need to refer to a solubility curve graph, which indicates how much of each solute will dissolve in #100"g"# water at indicated temperatures. A typical one looks like this:

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We need to look at how much #"CaCl"_2# will dissolve in #100"g" "H"_2"O"# at #10^oC#.

From the graph, the point of intersection between the #"CaCl"_2# curve (the orange line) and the #10^oC# line appears to occur at the point of roughly #64"g"# per #100"g"H_2O#

This means that at #10^oC#, #64"gCaCl"_2# will dissolve in #color(black)(100"gH"_2"O"#, but the question asks how much will dissolve in #color(black)(200"gH"_2"O"#. This can be found simply enough by doubling the solubility at #10^oC#:

#64"gCaCl"_2 xx 2 = 128"gCaCl"_2#.

So, #128"gCaCl"_2# will dissolve in #200"gH"_2"O"# at #10^oC#