Question

0.50 M H2SO4/050M CH3COOH 0.50 M NaNO3/0.50 M HNO3 0.50M NH3/0.50M NHACI Question 21 When 0.10 Lof 8.0 x 10M Pb(NO3 is mixed with 0.40L of 5.0x10 M Na SO.. will a precipitate form? (K for PbSO4-6.3 x 10) PUSO) = Pb( SO no because Qkap no because yes because OK ho because o yes because Q-ko Question 22 What is the pH0035 mol NaOH is added to 20 L of a butter contigo acetic acid.CHCOOH and 0.M sodium cette HCOON IK, for CH.COOH 15X105 MacBook

Answer 1

21)
Lets find the concentration after mixing for Pb(NO3)2
Concentration after mixing = mol of component / (total volume)
M(Pb(NO3)2) after mixing = M(Pb(NO3)2)*V(Pb(NO3)2)/(total volume)
M(Pb(NO3)2) after mixing = 0.008 M*0.1 L/(0.1+0.4)L
M(Pb(NO3)2) after mixing = 1.6*10^-3 M

Lets find the concentration after mixing for Na2SO4
Concentration after mixing = mol of component / (total volume)
M(Na2SO4) after mixing = M(Na2SO4)*V(Na2SO4)/(total volume)
M(Na2SO4) after mixing = 0.005 M*0.4 L/(0.4+0.1)L
M(Na2SO4) after mixing = 4*10^-3 M

So, we have now
[Pb2+] = 1.6*10^-3 M
[SO42-] = 4*10^-3 M

At equilibrium:
PbSO4     <---->     Pb2+     +          SO42-  

Qsp = [Pb2+][SO42-]
Qsp = (1.6*10^-3)*(4*10^-3)
Qsp = 6.4*10^-6

we have,
Ksp = 6.3*10^-7
Since Qsp is greater than ksp, precipitate will form
Answer: OPTION 5