1. Specific heat is short for “specific heat capacity”
QUESTION:
What is the specific heat of a substance if a 30.0 g sample has a heat capacity of 3.00 J/K? A J oC-1 g-1, B J g K-1, C J-1 K g
Specific heat is short for “specific heat capacity”
Specific heat, s, is heat capacity per gram
s = C/m
Given: C = 3.00 J/K, m = 30.0 g
s = C/m = (3.00 J/K) / (30.0 g) = J /K /g, = J /oC /g = J oC-1 g-1
What is the specific heat of a substance if a 30.0 g sample has a heat capacity of 3.00 J/K? Is it A… joule per degree celsius per gram
Or B joule gram per kelvin
Or C…10.0 per joule kelvin gram
PAUSE
CLICK Specific heat is actually short for specific heat capacity.
The adjective specific…
HIGHLIGHT specific in “specific heat capacity”
as used in science, generally means per gram.
CALLOUT “means per gram” pointing to highlighted term
CLICK So specific heat capacity means heat capacity per gram.
CLICK
Since specific heat is heat capacity per gram, we calculate it by dividing the heat capacity,
HIGHLIGHT C in “C/m”
CALLOUT “heat capacity” pointing to C in “C/m”
by the mass of the sample
HIGHLIGHT m in “C/m”
CALLOUT “mass” pointing to C in “C/m”
CLICK We are given that the heat capacity is 3.00 joule per kelvin.
HIGHLIGHT 3.00 J/K in given line and in problem
We are also given that the mass is 30.0 grams.
HIGHLIGHT 30.0 g in given line and in problem
CLICK Therefore, the specific heat is equal to …
…the heat capacity… 3.00 joule per kelvin
HIGHLIGHT divided by…
HIGHLIGHT “/”
the mass of the sample… 30.0 grams.
HIGHLIGHT
Carrying out the indicated calculation gives us a specific heat of joule per kelvin per gram
Since a temperature change of one kelvin corresponds to a one degree change on the Celsius scale,
we can also say that the specific heat is joule per degree celsius per gram
HIGHLIGHT “J /oC /g”
Or we can say write the unit as joules…. times reciprocal celsius degree… times reciprocal gram.
Therefore the correct answer is choice A.
CLICK PAUSE END RECORDING

2. Video ID: © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Assisted by Johuan Gasery In partial fulfillment of the requirements for CHEM 481, Fall 2008.