Answer : The mass of calcium chloride is, 116.84 grams
Solution : Given,
Molar mass of calcium chloride,
= 110.98 g/mole
Number of molecules of calcium chloride = 
As we know that,
1 mole of calcium chloride contains
molecules of calcium chloride
or,
1 mole of calcium chloride contains 110.98 grams of calcium chloride
Or, we can say that
As,
molecules of calcium chloride present in 110.98 grams of calcium chloride
So,
molecules of calcium chloride present in
of calcium chloride
Therefore, the mass of calcium chloride is, 116.84 grams
Answer : The pH will be, 3.2
Explanation :
As we known that the value of solubility constant of ferric hydroxide at
is, 
Amount or solubility of iron consumed = (1.800 - 0.3) mg/L = 1.5 mg/L
The given solubility of iron convert from mg/L to mol/L.

The chemical reaction will be:

The expression of solubility constant will be:
![K_{sp}=[Fe^{3+}]\times [3OH^-]^3](https://tex.z-dn.net/?f=K_%7Bsp%7D%3D%5BFe%5E%7B3%2B%7D%5D%5Ctimes%20%5B3OH%5E-%5D%5E3)
Now put all the given values in this expression, we get the concentration of hydroxide ion.
![2.79\times 10^{-39}=(2.7\times 10^{-7})\times [3OH^-]^3](https://tex.z-dn.net/?f=2.79%5Ctimes%2010%5E%7B-39%7D%3D%282.7%5Ctimes%2010%5E%7B-7%7D%29%5Ctimes%20%5B3OH%5E-%5D%5E3)
![[OH^-]=1.5\times 10^{-11}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D1.5%5Ctimes%2010%5E%7B-11%7DM)
Now we have to calculate the pOH.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)


Now we have to calculate the pH.

Therefore, the pH will be, 3.2
Answer:Zn(s) + H2SO4(aq) → ZnSO4(aq) + H2(g)
O2Zn(s) + H2SO4(aq) → 22nH(aq) + SO4(s)
Explanation:
Answer: when concentrations of acid and base are same, pH = pKa
PH = 12.38 pOH = 1.62
Explanation: pKa= -log(Ka)= 12.38. PH + pOH = 14.00
I think it’s B not rlly sure