All chemical reactions involve chemical energy, the energy stored in chemical bonds

Unit 4 (Ch. 9) – Reactions/Chem. Living Systems Bach 11/03/09

Calcium Chloride Lab

All chemical reactions involve chemical energy, the energy stored in chemical

bonds.

Remember that during a reaction, chemical bonds in the reactants break as they absorb energy. As new bonds form in the products, energy is released.

Energy is released or absorbed in the overall reaction depending on how the chemical energy of the reactants compares with the chemical energy of the products.

Problem:

Is the chemical reaction involving calcium chloride and water an exothermic reaction or an endothermic reaction?

Hypothesis:

I think that

Procedure:

1. Carefully open the zip lock bag containing CaCl2, so that nothing comes out of the bag.

2. Using the eyedropper, squirt 2 or 3 full droppers of water into the bag and immediately seal it closed.

3. Be very careful that nothing leaks out of your bag. (Do not turn it upside down, etc.)

4. Observe any changes as a result of adding water to the CaCl2.

5. Throw your sealed bag into the trash.

Observations:

(record your observations here)

Analyze and Conclude:

1. What is an endothermic reaction?

2. What is an exothermic reaction?

3. Is the mixture of CaCl2 and water an endothermic or exothermic reaction?

4. How do you know?

5. Is the energy of the products in this reaction higher or lower than the reactants?

6. Is heat being released or is heat being absorbed?

7. Sketch a drawing or graph of the energy changes in this chemical reaction.

All chemical reactions involve chemical energy, the energy stored in chemical bonds

Documents

Through this course, we have learned that chemical processes involve energy transformations

Chemical Bonding…. How Atoms Combine Bonding involve electrons in the outermost energy level Valence Electrons

Chapter 55 Ecosystems and Restoration Ecology · •Regardless of an ecosystem’s size, its dynamics involve two main processes: energy flow and chemical cycling •Energy flows

Chemical Reactions Ch 11. Chemical Reactions Reactions involve chemical changes in matter resulting in new substances Reactions involve rearrangement

Involve Report Energy

Nuclear Chemistry. Chemical vs. Nuclear Reactions Chemical reactions involve valence electrons and atoms bonding together. Nuclear Reactions involve the

Chemical Reactions Reactions involve chemical changes in matter resulting in new substances being formed. Reactions involve rearrangement and exchange

What do you visualize when thinking about chemical reactions? You probably imagine… o Heat, Light, Sound These are energy, and chemical reactions involve

4.1 Chemical Energy and ATP - Weebly · 4.1 Chemical Energy and ATP KEY CONCEPT All cells need chemical energy. 4.1 Chemical Energy and ATP ! The chemical energy used for most cell

ENERGY Energy Changes Temperature Chemical Energy

Ecosystem Energy Flow- Productivity · Ecosystem dynamics involve two main processes: energy flow (productivity) and chemical cycling (biogeochemical cycles) Energy flows through

12-1 Chemical Reactions That Involve Heat Law of conservation of energy - energy is neither created or destroyed. Most chemical reactions involve changes

Chapter 6 – Chemical Energy - Bayside School ofbaysideschoolofchemistry.com/.../02/Chapter-6-Chemical-Energy-1.pdf · Chapter 6 – Chemical Energy hemical Energy hemical energy

Chemical Reactions. Chemical reactions involve changes in matter the making of new materials with new properties accompanied by energy changes. Chemical

Chemical reactions involve changes in energy – Breaking bonds requires energy – Forming bonds releases energy These energy changes can be in the form

Energy, work and heat All processes in nature involve energy

Module 3 Heat and Energy in Chemical Reactions.. Introduction: Thermochemistry Chemical reactions often involve changes in temperature, and in the heat

Chemical Reactions. Reactions involve chemical changes in matter resulting in new substances Reactions involve rearrangement and exchange of atoms to

Nuclear Chemistry. Reactions Chemical Involve electrons Affected external factors (temp, pressure, catalyst) Nuclear Involve the nucleus Release WAY more

Ecology.Ecology Ecosystem dynamics involve two processes: energy flow and chemical cycling. We will Quickly follow the flow of energy by grouping species