Answer: 4.4 x 10^-7
Explanation:
The dissociation equation for this reaction is:
MgCO3 (s) → Mg+2 (aq) + CO3-2 (aq)
(Here 0.08 >>> x )

So the solubility MgCO₃ in a solution that containing 0.080 M Mg²⁺ is 4.4 x 10^-7
Answer:
The oxidizing agent is the MnO₄⁻
Explanation:
This is the redox reaction:
10 I⁻ (aq) + 2 MnO₄⁻ (aq) + 16 H⁺ (aq) → 5 I₂ (s) + 2 Mn²⁺ (aq) + 8 H2O (l)
Let's determine the oxidation and the reduction.
I⁻ acts with -1 in oxidation state and changes to 0, at I₂.
All elements in ground state has 0 as oxidation state.
As the oxidation state has increased, this is the oxidation, so the iodide is the reducing agent.
In the permanganate (MnO₄⁻), Mn acts with +7 in oxidation state and decreased to Mn²⁺. As the oxidation state is lower, we talk about the reduction. Therefore, the permanganate is the oxidizing agent because it oxidizes iodide to iodine
.100 mol CO2 x

using the values of the periodic you first add the masses of C (12.01g) and O (there are two so it'll be 32.00g). That value will give the mass of 1mole of CO2.
I hate to do this, but
https://youtu.be/Pft2CASl0M0 is a link to a mr andersen video. I dislike watching these cause this is what my teacher uses instead of actually having to teach herself.