Answer:

Explanation:
Hello there!
In this case, according to the solubility equilibrium of calcium hydroxide:

Whereas the equilibrium expression is:
![Ksp=[Ca^{2+}][OH^-]^2](https://tex.z-dn.net/?f=Ksp%3D%5BCa%5E%7B2%2B%7D%5D%5BOH%5E-%5D%5E2)
It is firstly necessary to calculate the molar solubility given the grams and volume of the dissolved solute:

Now, according to the Ksp expression, we plug in s as the solubility to obtain:

Regards!
Answer:
2.72g
Explanation:
The balanced equation of this reaction is given as follows:
Na2O + H20 --> 2NaOH
Based on this balanced equation, 1 mole of Na2O will produce 2 moles of NaOH.
First, we need to convert mass of Na2O into moles by using the formula;
mole = mass/molar mass
Molar mass of Na2O = 23(2) + 16
= 46 + 16
= 62g/mol
mole = 2.1g/62g/mol
mole of Na2O = 0.034mol
Hence, if 1 mole of Na2O will produce 2 moles of NaOH.
Then, 0.034mol of Na2O will produce (0.034 × 2) = 0.068mol of NaOH.
To convert mole of NaOH to mass, we use;
mole = mass/molar mass
Molar mass of NaOH = 23 + 16 + 1 = 40g/mol
0.068 = mass/40
mass of NaOH produced = 2.72g.