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Kemmi Major also does a titration. She measures 25.00 mL of unknown concentratio

ID: 519024 • Letter: K

Question

Kemmi Major also does a titration. She measures 25.00 mL of unknown concentration H_2SO_4(aq) and titrates it with 0.1000 M NaOH(aq). When she has added 42.18 mL of the base, phenolphthalein indicator turns light pink. What is the concentration (molarity) of Kemmi's H_2SO_4(aq) sample? (4 significant digits, units M) Doc Inmaking has done seven titrations, each starting with exactly 20.00 mL of HBr acid, and he has calculated his concentrations. Help Doc apply the 0.15 mL test by selecting all the titrations he should include in his average calculation. Calculated concentration of HBr = 0.3360 M, volume of NaOH used = 19.20 mL. Calculated concentration of HBr = 0.3229 M, volume of NaOH used = 18.45 mL. Calculated concentration of HBr = 0.3189 M, volume of NaOH used = 18.22 mL. Calculated concentration of HBr = 0.3254 M, volume of NaOH used = 1862 mL. Calculated concentration of HBr = 0.3234 M, volume of NaOH used = 18.48 mL. Calculated concentration of HBr = 0.3220 M, volume of NaOH used = 18.40 mL. Calculated concentration of HBr = 0.3215 M, volume of NaOH used = 18.37 mL.

Explanation / Answer

(6)

We know that

M1V1=M2V2

So

1-NaOH

2-H2SO4

M2=M1V1/V2=42.18*0.1/25=0.16872 M