NOM NOM NOM
A 0.0036 M solution of Calcium hydroxide, CaOH, FW = 74.09 g/mol would have a hydroxide ion concentration of . . .?
2(0.0036M) = [OH-]
[OH-] = 0.0072 = 7.2 x 10-3 M
Determine the volume of 0.013 M H2SO4 solution required to titrate 26.62 ml of a 0.013 M Ca(OH)2 solution
0.013M = 0.026N H2SO4
0.013 M = 0.026N Ca(OH)2
0.026(V1)=0.026(26.62)
V1 = 26.62ml
The pH of a 0.054M solution of the strong acid HCL would be?
[H+] = 0.054M
pH = -log(0.054)
pH = 1.27
What is the pH of a buffer solution made by mixing 0.40 M acetic acid (CH₃COOH) and 0.60 M sodium acetate (CH₃COONa)? The Ka for acetic acid is 1.8 × 10⁻⁵.
NH3 = 0.49M
NH4+ = 0.51M
pH = 4.96
The half life of technetium 99 is 6 hours if 15 micro murries are injected into patient, what is actively after 24 hours assuming no technetium is excreted?
0.94 micro Curies
A solution of Calcium hydroxide, Ca(OH)2 FW = 74.09 g/mol with a pH of 8.56 would have a hydroxide ion concentration of . . .?
[H+] = 10-8.56 = 2.8 x 10-9
pOH = 14-8.56 = 5.44
[OH-] = 10-5.44 =3.6 x 10-6
Determine the concentration of a sulfuric acid solution H2SO4 if 25.00ml of the solution is required to titrate 46.27ml of a 0.000183 M Al(OH)3 solution
0.00183M = 0.00549 N Al(OH)3
N1(25) = (0.00549)(46.27)
N1 = 0.01016
A solution with a pH of 8.56 would have a hydrogen ion concentration of?
[H+] = 10-8.56
[H+] = 2.75 x 10-9
You have 1.0 L of a buffer solution that is 0.30 M CH₃COOH and 0.30 M CH₃COONa. If you add 0.020 mol of NaOH to the solution, what is the new pH? (Ka of acetic acid = 1.8 × 10⁻⁵)
CH3COOH = 0.280mol
CH3COO- = 0.320mol
pH = 4.80
When Lead-210 undergoes beta decay, a beta particle is emitted and a new element is produced. What is that element?
210 Bi
83
A 0.35% m/v solution of sodium chloride FW 58.45 g/mole would have the same Osmolairty as which of the following?
A: 0.040 M solution of magnesium chloride
B: 0.12 M Solution of magnesium sulfate
C: 0060 M sucrose solution
A: 0.040 M solution of magnesium chloride
0.35% NaCl = 1.20 Osm
How much, in ml, of a 0.00680 M solution of calcium chloride can you produce from 0.0500 liters of a 0.450 M solution of CaCl2?
0.450(0.0500) = 0.00680(V1)
V1 = 3.3088L
V1 = 3308 ml
A solution that is 0.0020M in hydrofluoric acid, Ka = 7.2 x 10-4 would be expected to have a pH of?
[H+] = /(7.2x10-4)(0.0020)
[H+] = 0.0012
pH = -log(0.0012)
pH = 2.92
A buffer contains:
0.43 mol of NH₃ (base)
0.47 mol of NH₄⁺ (acid)
What is the pH?
(Kb of NH₃ = 1.8 × 10⁻⁵ → pKa ≈ 9.26)
pH = 9.22
Magnesium-226 undergoes alpha decay, followed by the emission of a gamma ray. What is the follow product of this decay
222 Ne
10
Which of the following 0.1N solutions will have the greatest conductivity?
A: Ascorbic Acid Ka = 7.9x10-5
B: Hydrofluoric acid Ka = 3.5x10-4
C: Propanoic acid Ka = 1.3x10-5
D: Formic acid Ka Ka = 1.8x10-4
Most charged particles (largest Ka)
B: Hydrofluoric acid Ka = 3.5x10-4
If you want to produce 1.500 L of a 0.00720 M solution of silver nitrate, AgNO3 FW=170 g/mole, how many ml of 0.295 M silver nitrate do you need to start with?
0.00720(1.500) = 0.295(V2)
V2 = 0.03661 L
V2 = 3.66 x 10-2 ml
The pH of a 0.0094 M solution of the strong acid sulfuric acid, H2SO4 FW = 98 g/mole would be?
0.0094 M = [H+]
pH = -log(0.0094)
pH = 2.03
If you have a buffer that has a concentration of 0.64 M in sodium acetate, NaC2H3O2 FW = 80 g/mole, and 0.32 M in acetic acid, HC2H3O2, FW = 60 g/mole, Ka = 1.8x10-5 , what is the pH of this solution
pH = pKa + log (anion/acid)
pH = 4.744 + log(0.64/0.32)
pH= 5.05
A radioactive isotope has a half-life of 10 hours. If you start with 80 grams, how much is left after 30 hours?
Every 10 hours = 1 half-life
30 hours = 3 half-lives
80→40→20→10 grams
The molar hydroxide ion concentration, [OH-], of a 0.0094 M solution of the strong acid sulfuric acid, H2SO4 FW = 98 g/mole would be expected to be?
0.0094 M = [H+]
pH = -log(0.0094) = 2.026
pOH = 14-2.026 = 11.973
[OH] = 10-11.973 = 1.1 x 10-12
Determine the volume of 0.016 M H3PO4 solution required to exactly neutralize 36.57 ml of a 0.016 M Ca(OH)2 solution
0.016M = 0.048N H3PO4
0.016M = 0.032N Ca(OH)2
0.048(V1) = 0.032(36.57)
V1 = 24.38 ml
Given the following weak acids and their Ka values, which one would form a 0.10 M solution with the lowest pH
A: Boric acid - Ka= 5.8 x 10-10
B: Phosphoric acid - Ka= 7.5 x 10-3
C: Sulfurous acid - Ka= 1.2 x 10-2
C: Sulfurous acid - Ka= 1.2 x 10-2
Calculate the ratio of NaNO2 to HNO2 required to create a buffer with pH = 6.9. Ka (HNO2 = 7.2=10-4)
pKa = 3.1426
Ration is 0.000175
If you bombard Lead-210 with an alpha particle, you produce energy, 3 high-energy neutrons and Carbon-14 and a second isotope. What is that isotope
197 Pt
78