[powell]

Hello, I've tried the search, but nothing relevant came up.

The following reaction takes place:

CaC2(s) + 2H20(l) --->C2H2(g) + Ca(OH)2

We are doing a multi-step, multi-day lab in school. Using powdered form CaC2(s), and a "chunk" form.
I hypothesized that the reaction rate of the powdered form will be faster, due to increased surface area.
We used a temperature probe while adding, and stirring the two reactants. In both cases of the powdered, and chunk form we had the water in a Styrofoam calorimeter, and then added the CaC2 to it.

the resulting graph on the computer from the probe had a higher incline, and a higher final temperature for the "chunk" CaC2. and a lower incline, and a lower final temperature for the powdered form.

My question is:

1.) did the heat created by the powdered form reaction escape from the surface of the water? (thereby resulting in a smaller final temperature).
2.) is the solid residue remaining in the cup Ca(OH)2?
3.) is it possible to find the rate of reaction from the time vs.  temperature graph?

Any help is greatly appreciated.