MATERIALS NEEDED: - Zinc Dust - NH4NO3 (Ammonium Nitrate) - Nacl (Table Salt)

Energy of Chemical Reactions LabNames:

MATERIALS NEEDED:
- zinc dust
- NH4NO3 (Ammonium Nitrate)
- NaCl (Table Salt)

- H2O(Water)
- watch glass
- dropper

-triple-beam-balance

- petri dish

-mortar and pastel (will be on counter and

shared, since we only have two)

-toothpick

-Goggles

-Apron

Procedures

1. Calibrate the triple beam balance.

2. Using the triple beam balance find the mass of the petri dish.

3. Move the slider one gram passed the mass of the petri dish.

4. Using measuring spoon slowly pour the NH4NO3 (Ammonium Nitrate) into the petri dish until it balances out.

5. Get the mortar and pastel from counter. Pour the NH4NO3 (Ammonium Nitrate) into mortar and pastel. Crush into a fine powder.

6. Pour on watch glass. Take mortar and pastel back to counter.

7. Calibrate the triple beam balance.

8. Using the triple beam balance find the mass of the petri dish.

9. Move the slider one gram passed the mass of the petri dish.

10. Using measuring spoon slowly pour the zinc dust into the petri dish until it balances out.

11. Pour on watch glass. Make sure it is poured right on top of the NH4NO3 (Ammonium Nitrate).

12. Calibrate the triple beam balance.

13. Using the triple beam balance find the mass of the petri dish.

14. Move the slider .25 of a gram passed the mass of the petri dish.

15. Using a measuring spoon slowly pour the NaCl (Table Salt) into the petri dish. (Hint: This will be a very small amount.)

16. Pour on watch glass. Make sure it is poured on top of the ammonium nitrate and zinc.

17. Use a toothpick to mix the chemicals together. Make sure they are mixed well!!!!

18. Form the chemicals into a mound in the middle of the watch glass.

19. Get water from sink into pipette.

20. Put 2 drops of water on top of the mixture.

21. Observe what happens. Write observations in box on front page. Hints: Write down how long the reaction took, the color, the smell etc.

CLEAN UP – Wash watch glass thoroughly. It will be hard to get new substance off the glass. Use sponge if necessary. Make sure your lab table is nice and neat. Put goggles and apron back. Go to front of the room to answer the questions.

Complete the following questions in complete sentences.

1. Look up endothermic in the index of the science book. Read the paragraph and then write a definition for endothermic.

2. Look up exothermic in the index of the science book. Read the paragraph and the write a definition for exothermic.

3. Was the chemical reaction you observed endothermic or exothermic? Explain why. (At least 2 sentences here)

4. Look up catalyst in the index of the science book. Read the paragraphs and write in 3 or more sentences on what a catalyst is and what happens to a catalyst during a chemical reaction.

5. The following chemical equation is what took place in this lab. Circle the subscripts in the formula and put a square around the coefficients of this equation.

Zn + NH4NO3 → N2 + ZnO + 2 H2O

6. What chemical is missing from the equation and why?