Third quarter (or last quarter)
Answer:
Cr(s) ⟶ Cr⁴⁺(aq) + 4e⁻
Explanation:
1. Write the skeleton half-reaction
Cr(s) ⟶ Cr⁴⁺(aq)
2. Balance charge
Add electrons to the side that needs them.
You have 4+ on the right and 0 on the left. You must add 4e⁻ to the right to balance the charge.
Cr(s) ⟶ Cr⁴⁺(aq) + 4e⁻
Answer:
Its atomic mass increases by 1
An isotope of that element is fotmed with mass differences by 1
Explanation:
It’s easy, if the PH of any acidic solution = -Log[H+], where [H+] is hydrogen ion concentration, multiply each term by (-1) then raise each term as a power to (10), so it will become like this:-
[H+] = 10^(-PH)
Answer:
450. g of 0.173 % KCN solution contains 779 mg of KCN.
Explanation:
Mass of the solution = m
Mass of the KCN in solution = 779 mg
Mass by mass percentage of KCN solution = 0.173%



1 mg = 0.001 g
m = 450,289 mg × 0.001 g = 450.289 mg ≈ 450. g
450. g of 0.173 % KCN solution contains 779 mg of KCN.