Question

1. a. provide one example of an endothermic or exothermic reaction (different front the lab)

b. illustrate an example.
c. draw arrows whether energy is moving into or out of the object
d. briefly describe the chemical reaction.
e. color and label

Explanation:

Step1: Choose an exothermic reaction

Combustion of methane is a common exothermic reaction.

Step2: Provide real - life illustration

Gas - stove burning natural gas is a familiar example.

Step3: Determine energy direction

Exothermic reactions release energy, so arrows point outwards.

Step4: Describe chemical reaction

Bonds are broken and formed during combustion.

Step5: Color and label

Use colors and labels for clarity in representation.

Answer:

a. An example of an exothermic reaction is the combustion of methane. The chemical equation for the combustion of methane ($CH_4$) in the presence of oxygen ($O_2$) is $CH_4 + 2O_2
ightarrow CO_2+2H_2O$.
b. For illustration, consider a gas - stove. When natural gas (which is mainly methane) is burned, it releases heat and light.
c. For the combustion of methane, arrows should be drawn pointing outwards from the reaction site to represent the energy moving out of the object (the methane - oxygen reaction system).
d. In the combustion of methane, methane reacts with oxygen. The carbon - hydrogen bonds in methane and the oxygen - oxygen bonds in $O_2$ are broken. New bonds are formed between carbon and oxygen to create carbon dioxide and between hydrogen and oxygen to form water. This process releases a large amount of energy in the form of heat and light.
e. One could color the methane and oxygen molecules in one color (e.g., blue), and the carbon dioxide and water molecules in another color (e.g., red). Label the methane as $CH_4$, oxygen as $O_2$, carbon dioxide as $CO_2$ and water as $H_2O$. Also, label the arrows representing energy release as "Energy out".