Answer:
You need to dilute 8 M HCl to 0.35 M to make 457 mL.
Explanation:
Use the equation M₁V₁=M₂V₂
Convert the mL to L : 20 mL= 0.02 L
8 M x 0.02 L = 0.35 M x V₂
V₂ = 0.4571429 L = 457 mL
Fe3O4 + 4H2 = 3Fe + 4H2O
Fe3O4 + 4H2SO4 = Fe2(SO4)3 + FeSO4 + 4H2O
The pH of a solution is 9.02.
c(HCN) = 1.25 M; concentration of the cyanide acid
n(NaCN) = 1.37 mol; amount of the salt
V = 1.699 l; volume of the solution
c(NaCN) = 1.37 mol ÷ 1.699 l
c(NaCN) = 0.806 M; concentration of the salt
Ka = 6.2 × 10⁻¹⁰; acid constant
pKa = -logKa
pKa = - log (6.2 × 10⁻¹⁰)
pKa = 9.21
Henderson–Hasselbalch equation for the buffer solution:
pH = pKa + log(cs/ck)
pH = pKa + log(cs/ck)
pH = 9.21 + log (0.806M/1.25M)
pH = 9.21 - 0.19
pH = 9.02; potential of hydrogen
More about buffer: brainly.com/question/4177791
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