Find the pH of a solution prepared from 1.0 L of a 0.20 M solution of Ba(OH)2 and excess Zn(OH)2(s). The Ksp of Zn(OH)2 is 3×10−15 and the Kf of Zn(OH)42− is 2×1015.
In: Chemistry
1. An aqueous solution of sodium hydroxide is
standardized by titration with a 0.108 M solution
of perchloric acid.
If 17.0 mL of base are required to neutralize
29.4 mL of the acid, what is the molarity of the
sodium hydroxide solution?
______ M sodium hydroxide
2. An aqueous solution of
potassium hydroxide is standardized by titration
with a 0.130 M solution of nitric
acid.
If 23.3 mL of base are required to neutralize
15.8 mL of the acid, what is the molarity of the
potassium hydroxide solution?
________M potassium hydroxide
3. An aqueous solution of
hydrobromic acid is standardized by titration with
a 0.140 M solution of barium
hydroxide.
If 27.7 mL of base are required to neutralize
26.9 mL of the acid, what is the molarity of the
hydrobromic acid solution?
_______M hydrobromic acid
In: Chemistry
Refer to the reaction 2Mg + O2---> 2MgO
starting amounts 1.25mg 2Mg, and 25g of O2. What are the changes that occur in this reaction as its happening? Complete an ice table using the starting amounts and referring to the reaction above.
*I have no idea how to do these, in the words of Micheal Scott, "Why don't you explain this to me like I'm 5 years old."*
In: Chemistry
In the laboratory, a general chemistry student measured the pH of a 0.530 M aqueous solution of codeine, C18H21O3N to be 10.820. Use the information she obtained to determine the Kb for this base.
In: Chemistry
Which choice is expected to form (a) the strongest and (b) the weakest ionic bond (choices listed as strongest/weakest)?
Options:
Na+ & Cl-, Cs+ & Cl-, Cs+ & Br-, Ca2+ & Cl-,
Ca2+ & O2-, Sr2+ & O2-, Sr2+ & Cl-, Sr2+ & Br-
| Sr2+ & O2–/Ca2+ & Cl– |
| Ca2+ & O2–/Sr2+ & Cl– |
| Cs+ & Cl–/Sr2+ & Br– |
| Ca2+ & O2–/Cs+ & Br– |
| Na+ & Cl–/Cs+ & Br– |
In: Chemistry
Electric generating plants transport large amounts of hot water
through metal pipes, and oxygen dissolved in the water can cause a
major corrosion problem. Hydrazine (N2H4)
added to the water avoids the problem by reacting with the oxygen:
N2H4(aq) + O2(g)
→ N2(g) + 2 H2O(l)
About 4 x107 kg of hydrazine is produced every year by
reacting ammonia with sodium hypochlorite in the Raschig
process:
2 NH3(aq) + NaOCl(aq) →
N2H4(aq) + NaCl(aq) +
H2O(l) ΔrH° = −151 kJ
(a) If ΔfH° of NaOCl(aq) =
−346 kJ/mol, find ΔfH° of
N2H4(aq) given that
ΔfH° [NH3(aq)] = −80.83
kJ/mol, ΔfH° [NaOCl(aq)] = −346
kJ/mol, ΔfH° [Na+(aq)] =
−239.66 kJ/mol, ΔfH°
[Cl−(aq)] = −167.46 kJ/mol and
ΔfH° [H2O(l)] = −285.840
kJ/mol.
______ kJ/mol
b) What is the heat released when aqueous
N2H4 is added to 6.00 × 103 L of
plant water that is 2.50 × 10−4 mol/L O2?
Enter your answer in scientific notation.
____× 10___ kJ
In: Chemistry
1.True or false
A. All compounds that contain hydrogen are acids..
B. A solution with a pH of 5 has 10 times higher [H+] than a
Solution with a pH of 6.
C. SO3 in the atmosphere is one cause of acid rain.
D. Agricultural chemicals are the only cause of water pollution.
E. One function of an auto catalytic converter is to convert CO2 to CO
F. The major elements in air are nitrogen and oxygen
G As a radioactive isotope decays its half life changes.
H. In the same size container at the same temperature, 25g of N2 gas
has the same pressure as 25g of NH3 gas..
I Chloroflurocarbon compounds are considered to be a prime cause of
ozone depletion in the stratosphere.
J. Beta radiation from an atom is the emission of a valence electron.
In: Chemistry
Fe(NO3)3+KSCN ---- FeSCN^2+KNO3
the assumption was made that all of the SCN^- which had been added to the standard solutions had been converted to FeSCN^2+.
Is this assumption reasonable. Explain considering the initial concentration of SCN- relative to that of Fe3+ in each sample
| soln |
0.200M Fe(NO3)3 (ml) |
0.00200M KSCN (ml) |
water (ml) |
FeSCN2+ (ml) |
|---|---|---|---|---|
| 1 | 5.00 | 0.20 | 4.80 | 4x10^-5 |
| 2 | 5.00 | 0.40 | 4.60 | 8x10^-5 |
| 3 | 5.00 | 0.60 | 4.40 | 1.2x10^-4 |
| 4 | 5.00 | 0.80 | 4.20 | 1.6x10^-4 |
| 5 | 5.00 | 1.00 | 4.00 | 2.00x10-4 |
In: Chemistry
1. 3. Consider the dissociation of acetic acid: CH3COOH(aq) + H2O(l) ⎯→ ←⎯ CH3COO-(aq) + H3O+(aq) Ka = 1.8 x 10-5 pKa = 4.74
a. Write the equilibrium expression.
b. Would the addition of an aqueous solution of sodium hydroxide favor the dissociation of acetic acid? Explain your answer.
c. Would the addition of an aqueous solution of sodium acetate favor the dissociation of acetic acid? Explain your answer.
In: Chemistry
Not counting solubility relations and effectiveness for removal of impurities, in whatrespects would hexyl alcohol be a less desirable crystallization solvent thanmethanol or ethanol (hint: look at MSDS physical and chemical properties)
In: Chemistry
Write the net ionic equation for the following reactions in solution.
A) Solutions of lithium chromate and barium chloride are mixed
B) Solutions of ammonium acetate and barium hydroxide are mixed
C) Solutions of Acetic acid and potassium hydrogen carbonate are mixed
In: Chemistry
Substance Q reacts according to a first order rate law with k = 5.0 x 10-5 s -1 .
a. If the initial concentration of the reaction is 1.00 M for Q, what is the initial rate of the reaction?
b. What is the rate after 1.00 hr?
In: Chemistry
What volume of 6.00 M HNO3 is needed to make 500.0 mL of a 0.250 M solution?
In: Chemistry
What are glycosaminoglycans, and why are sugars good candidates for molecules that fill that role
In: Chemistry
In: Chemistry