ShmoopTube

Where Monty Python meets your 10th grade teacher.

Search Thousands of Shmoop Videos

AP Chemistry 1.1 Laws of Thermodynamics 228 Views

Share It!

Description:

AP® Chemistry: Laws of Thermodynamics Drill 1, Problem 1. Which equation represents the heat of formation for Calcium Chloride?

Language:

English Language

Subjects:

Tags:

AP Chemistry / Chemical and Physical Properties from Structure and Arrangement

Common Core Standards:

Transcript

00:03
Here's your shmoop du jour, brought to you by Calcium Chloride. Roads need it to grow
00:08
up big and strong. Or... to keep from getting icy, or whatever.
00:13
Which equation represents the heat of formation for Calcium Chloride?
00:18
And here are your potential answers...
00:26
Even if we have no idea about what the heat of formation is... let's think about it. FORMATION.

00:32
We probably want the compound calcium chloride to be on the RIGHT side of the equation...
00:36
since that's what's being FORMED. Which means we can immediately eliminate C.
00:44
So now to learn what a heat of formation equation...is.
00:49
A heat of formation equation shows the elements that make up the compound to be formed, in
00:53
their standard state. It's important that they're in their standard
00:57
state...which is basically whether they're solid, liquid, or gas at room temperature.
01:02
Calcium is a solid at room temperature, and chlorine is a gas at room temperature...
01:06
but a diatomic molecule...
01:13
Meaning that it looks like Cl 2, not 2 Cl.
01:17
These two molecules are in their standard states in option (D).
01:21
D's our answer. We haven't had so much fun with formation
01:24
since we got that lifetime supply of Play-doh...
Full Transcript