ana. chem Flashcards

(21 cards)

1
Q

In a titration experiment, a student finds that 23.48 ml of NaOH solution are needed to neutralize 0.5468 g of KHP (MW: 204.2). What is the conc (in molarity) of the NaOH solution?

A. 0.15 M
B. 0.13 M
C. 0.11 M
D. 0.09 M

A

C. 0.11 M

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2
Q

50.00 ml portion of an HCl solution required 29.71 ml of 0.01963 M Ba(OH)2 to reach an endpoint with bromocresol green indicator. Calculate the molarity of the HCl.

A. 0.01 M
B. 0.02 M
C. 0.03 M
D. 0.04 M

A

B. 0.02 M

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3
Q

Problem 10-12. Calculate the pH in the titration of 25 ml of 0.1 M HCl by NaOH after the addition to the acid solution of 10 ml, 25 ml, and 35 ml of 0.1 M NaOH.

  1. 10 ml of 0.1 M NaOH
    A. 1.37 B. 1.73 C. 1.48 D. 1.84
  2. 25 ml of 0.1 M NaOH
    A. 7 B. 14 C. 4 D. 1
  3. 35 ml of 0.1 M NaOH
    A. 13.12 B. 10.12 C. 11.34 D. 12.22
A
  1. A. 1.37
  2. A. 7
  3. D. 12.22
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4
Q

Ksp of AgCl at room temperature is 1x10-10. Calculate the Ag+ ion concentration in ppm in a 0.01 M NaCl solution.

A. 0.001079
B. 0.0024
C. 0.0035
D. 0.0042

A

A. 0.001079

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5
Q

In an acidic solution, 25 ml of 0.021 M KMnO4 oxidize Fe2+ to Fe3+. Calculate the mass of Fe2+ (55.85g) oxidized

A. 14.66mg
B. 25.32mg
C. 2.55mg
D. 146.6mg

A

A. 14.66mg

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6
Q

The presence of the following cations od solutions maybe confirmed by
conducting flame tests, except:

A. Ba+2
B. Na+1
C. Ca+2
D. Ni+2

A

D. Ni+2

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7
Q

A small amount of KI is added to solution of NaCN. 35 mL of 0.1200 M AgNO3 is required to produce a precipitate of AgI. Find the milligrams of NaCN present.

A. 245.6 mg
B. 378.6 mg
C. 397.5 mg
D. 411.8 mg

A

D. 411.8 mg

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8
Q

0.7500 g sample of an alloy steel yielded on electrolysis 0.1532 g of a mixed deposit of Co and Ni. This is dissolved, and the precipitated nickel dimethylglyoxime (NiC8H14N4O4) weighs 0.3560 g. What is the percentage of the Ni in the alloy?

A. 9.64% Ni
B. 10.79%Ni
C. 12.43
D. 13.79% Ni

A

A. 9.64% Ni

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9
Q

In the titration of a water sample using double indicator, the volume of standard acid required for the methyl orange endpoint is equal to the volume required for the phenolphthalein endpoint. The impurity (ies) is/are:

A. NaOH only
B. Na2CO3 only
C. NaHCO3 only
D. Na2CO3 and NaOH

A

B. Na2CO3 only

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10
Q

The pH value at equivalence point when titrating a weak acid against a strong base is

A. at exactly 7
B. greater than 7
C. less than 7
D. neutral

A

B. greater than 7

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11
Q

EDTA is
A. not useful as a chelating agent
B. an effective antidote for heavy metal poisoning
C. known to form unstable complex ions with Fe3+, Hg2+, and Zn2+
D. a monodentate ligand

A

B. an effective antidote for heavy metal poisoning

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12
Q

Which response gives the products of hydrolysis of KF?
A. KOH and HF
B. OH- and HF
C. KOH, H+ and F-
D. no hydrolysis

A

D. no hydrolysis

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13
Q

A grain sample as received contains 10% moisture. If after drying, the dried sample contains 15% N, then the %N in the as received sample is

A. 13.5
B. 16.67
C. 15
D. 5

A

A. 13.5

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14
Q

Calculate the molarity of NaOH solution if 12.25 ml was used to titrate 0.2615mgrams of primary standard KHP

A. 0.2118
B. 0.1354
C. 0.1045
D. 0.1697

A

C. 0.1045

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15
Q

What weight of Mn ore should be taken so that the percentage of MnO2 in the ore can be found by multiplying by 5 the number of centigrams of Mn3O4 obtained?

A. 2.28 g
B. 2.28 cg
C. 228 g
D. 0.228 g

A

D. 0.228 g

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16
Q

A 10.0 ml solution containing Cl- was treated with excess AgNO3 to precipitate 00.4368 g of AgCl. What was the concentration of Cl- in the unknown? (AgCl = 143.321 g/mol)

A. 0.0384 M
B. 0.8048 M
C. 0.3048 M
D. 0.4038 M

17
Q

When a sample of impure potassium chloride (0.4500 g) was dissolved in water and treated with an excess of silver nitrate, 0.8402 g of silver chloride was precipitated. Calculate the percentage KCl in the original sample.

A. 96.27%
B. 92.16%
C. 96.12%
D. 97.12%

18
Q

The precipitant commonly used for the determination of calcium in gravimetric analysis is ___.

A. NH3
B. H2C2O4
C. H2PtCl6
D. HF

19
Q

Which of the following is a bidentate ligand?
A. CN-
B. NH3
C. CO
D. H2NCH2CH2NH2

A

D. H2NCH2CH2NH2

20
Q

Which gas is formed in the Kjeldahl analysis of nitrogen in the sample?

A. NH3
B. H2
C. N2
D. NH4Cl

21
Q

When KMnO4 is reacted with Fe2+ in acid medium, Mn2+ and Fe3+ are formed. The equivalent weight of KMnO4 in this reaction is equal to

A. FM/2
B. FM/4
C. FM/5
D. FM/7