Question

Science Experiment Questions Help please

Answer 1

Temperature and Chemical Change Activity
Directions: Complete the following activity and then answer the questions below in complete sentences.
Materials:
• One disposable plastic cup
• One disposable plastic spoon (plastic fork or knife may be used instead)
• Thermometer (if you have one)
• Measuring cup and spoon
• Newspaper (Use it to cover the countertop next to the kitchen sink. This could get a little messy!)
Procedure:
1. Pick one of the following combinations to investigate in this activity.
A. Vinegar and baking soda (NaHCO3)
B. Room temperature water and powdered washing soda (Na2CO3)
C. Vinegar and table salt (NaCl)
2. Measure two tablespoons of the appropriate powder (baking soda, washing soda, or table salt) and pour it into the clean, dry plastic cup.
3. Measure out one cup of the appropriate liquid (vinegar or water).
4. If you have a thermometer, place it in the measuring cup of liquid and write down the initial temperature.
5. Grasping the plastic cup near the bottom with one hand, pour the liquid into the plastic cup with your other hand.
6. Continue to grasp the cup as you stir the solution gently with the plastic spoon. Observe any temperature change felt through the plastic cup.
7. If you have a thermometer, record the temperature change as you stir the solution very gently.
8. When you are finished making observations, it is safe to pour the solution down the sink and to dispose of the cup and spoon in the trash. If you used a thermometer, be sure to wash it before putting it away.
Anaylysis and Conclusion:
1. What chemical combination did you investigate?
Salt and Vinegar
2. Did the observed temperature of the solution increase or decrease?
Decrease
3. Based on your observation, was the reaction endothermic or exothermic? Explain your answer using complete sentences.
4. Describe in detail the relationship between chemical bonds and energy. What must be true of the bonds for a reaction to be endothermic, and what must be true for the reaction to be exothermic?

Answer 2

@sweetburger i need help with questions 4 and 5 only please

Answer 3

I think question 5 may have not been included.

Answer 4

okay then only question 4 please

Answer 5

For question 4. Endothermic reactions have lower energy bonds in in the reactants and and higher energy bonds in the products. This means that the reactants must absorb energy from the surroundings to allow for the reaction to go forward.
Exothermic reactions have higher energy bonds in the reactants and lower energy bonds in the products which allows for heat to be released when the reaction is complete.

Answer 6

I don't know if that covers what you were wondering.

Answer 7

sorry didanother science experiment put thanks