<span>Balanced half-reaction: Au</span>⁺<span>(aq) </span>→ <span> Au</span>³⁺(aq) + 2e⁻.
Oxidation reaction is increasing of oxidation number of element, because element or ion lost electrons in chemical reaction.
Gold lost two electrons and change oxidation number from +1 to +3.
Reduction is lowering oxidation number because element gain electrons.
<u>Answer:</u> The concentration of diluted bleach solution is 0.0157 M
<u>Explanation:</u>
To calculate the molarity of the diluted solution, we use the equation:

where,
are the molarity and volume of the concentrated bleach solution
are the molarity and volume of diluted bleach solution
We are given:

Putting values in above equation, we get:

Hence, the concentration of diluted bleach solution is 0.0157 M
Answer:
(a) See below
(b) 103.935 °F; 102.235 °F
Explanation:
The equation relating the temperature to time is

1. Calculate the thermometer readings after 0.5 min and 1 min
(a) After 0.5 min

(b) After 1 min

2. Calculate the thermometer reading after 2.0 min
T₀ =106.321 °F
ΔT = 100 - 106.321 °F = -6.321 °F
t = t - 1, because the cooling starts 1 min late

3. Plot the temperature readings as a function of time.
The graphs are shown below.
Activation energy is defined as the least amount of energy that is needed to be available in a chemical system with potential reactants in order to result a chemical reaction. Therefore, the correct answer would be the first option: the heat released in a reaction.