Chem Notebook COmplete

Step Three: liquid water rises in temperature
Once the ice is totally melted, the temperature can now
begin to rise again.
It continues to go up until it reaches its normal boiling
point of 100.0 °C.
Since the temperature went from zero to 100, the Δt is
100.
Here is an important point: THE LIQUID HAS NOT
BOILED YET.
At the end of this step we have liquid water at 100 degrees. It has not turned to steam yet.
Each gram of water requires a constant amount of energy to go up each degree Celsius. This amount
of energy is called specific heat and has the symbol c. There will be a different value needed,
depending on the substance being in the solid, liquid or gas phase.
72.0 grams of liquid water is 0.0 °C. It is going to warm up to 100.0 °C, but at that temperature, the
water WILL NOT BOIL. We need to calculate the energy needed to do this.
This summarizes the information needed:
Δt = 100.0 °C (100.0 °C – 0.0 °C)
The mass = 72.0 g
c = 4.184 Joules per gram-degree Celsius
The calculation needed, using words & symbols is:
q = (mass) (Δt) (c)
Why is this equation the way it is?
Think about one gram going one degree. The liquid water needs 4.184 J for that. Now go the second
degree. Another 4.184 J. Go the third degree and use another 4.184 J. So one gram going 100
degrees needs 4.184 x 100 = 418.4 J. Now we have 72 grams, so gram #2 also needs 418.4, gram
#3 needs 418.4 and so on until 72 grams.
With the numbers in place, we have:
q = (72.0 g) (100.0 °C) (4.184 J/g °C)
So we calculate and get 30124.8 J. We won't bother to round off right now since there are two more
calculations to go. We will have to do five calculations and then sum them all up.
Notes: