Choose the correct one:
1) 25.00 mL is taken from a solution containing NaOH, NaHCO3 and Na2CO3 individually or as a mixture.
up to the phenolphthalein milestone when analyzed
When 11.00 mL of 0.100 M HCl is taken and a second 25.00 mL is taken and titrated to the bromocresol green turning point, 11.02 mL of HCl is consumed. Find the composition of the solution.
a) NaOH
b) NaHCO3
c) Na2CO3
d) NaOH+ Na2CO3
e) NaHCO3 +Na2CO3
2) H2C2O4 with concentrations of 0.0400 M and 0.200 M
Calculate the pH of a solution containing NaHC2O4.
(Ka1 = 5.60x10-2; Ka2 = 5.42x10-5)
a. 1.01
b. 3.45
c. 4.08
D. 5.67
E. 6.89
3) Containing cadmium (Cd2+) and lead (Pb2+) ions
The titration of a 25.00 mL sample with 0.0040 M EDTA consumes 39.10 mL of EDTA. The cadmium in the sample is then masked by forming Cd(CN)4^-2 with excess KCN. This time 28.00 mL for titration
EDTA is wasted. Cd2+ (112.4 g mol-1) in the sample and
Pb2+ (207.2 g mol-1) concentrations are given below
which one?
Pb2+ (M) / Cd2+ (M)
a. 0.112 /0.044
b. 1.1×10-2 / 4.4×10-3
c. 4.48×10-2/8.8×10-3
D. 4.48×10-3/8.8×10-4
E. 8.8×10-3/4.48×10
0 answers