A polyatomic ion.
Examples: Sulfate, Sulfite, Nitrate, Nitrite...
Answer:

Explanation:
We know we will need a balanced chemical equation with masses and molar masses, so, let's gather all the information in one place.
You don't tell us what the reaction is, but we can solve the problem so long as we balance the OH.
M_r: 58.32
Mg(OH)₂ + … ⟶ … + 2HOH
m/g: 58.3
(a) Moles of Mg(OH)₂

(b) Moles of H₂O
The molar ratio is 2 mol H₂O = 1 mol Mg(OH)₂.

The reaction will form
of water.
This is a dilution that requires a certain volume from the stock solution to be diluted with distilled water to make a solution of HBr with a lesser concentration than the stock solution
Following dilution formula can be used
c1v1 = c2v2
Where c1 is concentration and v1 is the volume of the stock solution
c2 is concentration and v2 is volume of the diluted solution to be prepared
Substituting these values
10.0 M x v1 = 3.0 x 450.0 mL
v1 = 135.0 mL
A volume of 135.0 mL from HBr stock solution needs to be taken and diluted with distilled water upto 450.0 mL. The resulting solution will have a concentration of 3.0 M
Ookay
1) T
2) T
3) F
Hope i helped :)