This is a reduction half-reaction. Initially, gold exists as

, and after the reaction, it has been converted to elemental gold. To make this possible, three electrons must be added to <span>

. This fits within the definition of reduction reactions, where the reactant gains electrons in the reaction.</span>
Answer:
625 mL
Explanation:
From the question given above, the following data were obtained:
Volume of stock solution (V₁) = 250 mL
Molarity of stock solution (M₁) = 5 M
Molarity of diluted solution (M₂) = 2 M
Volume of diluted solution (V₂) =?
The volume of the diluted solution can be obtained by using the dilution formula as illustrated below:
M₁V₁ = M₂V₂
5 × 250 = 2 × V₂
1250 = 2 × V₂
Divide both side by 2
V₂ = 1250 / 2
V₂ = 625 mL
Therefore, the volume of the diluted solution is 625 mL.
1 is b 2 is a 3 is d 4 is a 5 is c