Wednesday, January 27, 2010

Ch 12 Energy Introduction

Check out this SlideShare Presentation:

Chemical Reaction Of Heat

Check out this SlideShare Presentation:


Here it is, a version of the quiz I used last year. Your quiz will look very similar.

Chem QUIZ Energy Name ________________________________________

1. In this chapter we are studying energy. Energy is the ability to do __________________ .

2. One calorie = ________ joules

3. 1000 calories = ____________ food calorie or ___________ kcal.

4. What are the most common units scientists use for energy? _______________

4a. These units are really a combination of five S.I. Units. What are they? _________________

5. The specific heat of water is 1.0 cal/gdegC Liquid X has a specific heat of 2 cal/gdegC -- Using this information which statement is correct.
A. The water will heat up twice as slow as liquid X.
B. The water will boil twice as fast as liquid X.
C. Liquid X is two times easier to heat up that water.
D. Liquid X heats up twice as slow as water.

6. A food label says “180 Calories in each 30 gram serving of chips” How much heat will be given off if you burn 3 grams of chips?

________________ Kcal

7. A food label says “160 Calories in each 20 gram serving of cheetos.” If you burn 4 grams of these

cheetos you will be able to heat up ___________ grams of water from 10 deg C to 60 deg C.

8. The pop can we used is called a _________________ by real scientists.

9. In lab you want to heat up 350 g water that starts at 10 deg C. Mass of empty crucible = 12.4 grams, mass of crucible with ethanol = 13.4 grams. Your teacher told you the actual heat of combustion of ethanol is 7 kcal/gram.
If you assume 100% efficiency, what is the final temp of the water? ________ deg C

9. You have just burned 2.6 grams of dried bananas to heat up 220 grams of water from 10 deg C to 42 deg C. Calculate the energy content of dried bananas in Kcal/g

___________ kcal/g

Wednesday, January 6, 2010


chem quiz !! study up.
I've put up helpful review powerpoints on my slideshare acct.

here's an old practice quiz.

SHOW ALL WORK !! (use unit analysis)

When sodium reacts with water it forms sodium hydroxide and hydrogen gas.

2Na + 2 H2O YIELDS 2NaOH + H2

1. If you want to react 12 atoms of Na it will require _____ molecules of water and it will make _______ FU’s NaOH and _______ molecules of H2

2. If 50 grams of sodium is mixed with 30 grams water, which is in excess?

3. How much NaOH will be made ? ______________ grams

4. How much hydrogen gas will be made? ____________ grams

5. How much hydrogen gas will be made? ____________ liters

6. How much of the reactant which is in excess will be LEFT OVER? _________ g

7. If you had 2.5 grams Na reacting with EXCESS water, how many mole hydrogen gas will be made?

Extra credit – If you made 12 liters of hydrogen gas, how many ATOMS of sodium reacted with excess water? Show work !