Asked by Sarah
A 1.994 g sample of gypsum, a hydrated salt of calcium sulfate, CaSO4, is heated at a temp. above 170 C in a crucible until a constant mass is reached. The mass of anhydrous CaSO4 salt is 1.577 g.
Calculate the percent by mass of water in the hydrated calcium sulfate salt.
This is what I did....
1.577/1.944 * 100 = 79.09%
100-79.09 = 20.91% water.
Is this correct? Thanks for your help!
Calculate the percent by mass of water in the hydrated calcium sulfate salt.
This is what I did....
1.577/1.944 * 100 = 79.09%
100-79.09 = 20.91% water.
Is this correct? Thanks for your help!
Answers
Answered by
DrBob222
Yes, it's correct. Another way you could have done it (but no more correct than the way you did it) is
1.994 g = hydrated CaSO4
-1.577 g = anhydrous material
-----------
0.417 g = mass water driven off
%H2O = (0.417/1.944)*100 = 20.913 which I would round to 20.9%.
1.994 g = hydrated CaSO4
-1.577 g = anhydrous material
-----------
0.417 g = mass water driven off
%H2O = (0.417/1.944)*100 = 20.913 which I would round to 20.9%.
Answered by
Sarah
Thank you!