Answer:
Answer is Ca2+(aq)+S2-(aq)=>CaS(s)
Explanation:
I hope it's helpful!
The acid dissociation constant of benzoic acid is 6.5 x 10^-5. Therefore, the pH of the benzoic acid solution prior to adding sodium benzoate is:
pH = -log[Ka]
pH = -log (6.5 x 10^-5)
pH = 4.19
The pH of the benzoic acid solution is 4.19 which is acidic, but a weak acid.
your answer is b hope this helps
Ca + 2HCl = CaCl₂ + H₂
c=4.50 mol/l
v=2.20 l
n(HCl)=cv
m(Ca)/M(Ca)=n(HCl)/2
m(Ca)=M(Ca)cv/2
m(Ca)=40g/mol·4.50mol/l·2.20l/2=198 g
198 grams of Ca are needed