i have 2 chemistry questions. please give me correct answers. thank you .
1. Calculate the pH of a 0.23 M solution of acetic acid (CH3COOH).
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DATA : pKa (CH3COOH) = 4.76 |
Answer:
2.
Calculate the pH of a 0.37 M solution of potassium cyanide (KCN).
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DATA : pKa (HCN) = 9.21 |
Answer:
In: Chemistry
Calculate the concentrations of H2C2O4, HC2O4^ -, C2O4^ -2, and
H^+ species in a 0.430 M Oxalic Acid Solution
(Ka1 = 6.5 x 10^-2)
(Ka2 = 6.1 x 10^-5)
Be sure to answer in correct number of significant figures.
H2C2O4 = ________ M
HC2O4^- = _________ M
C2O4^2- = _________ x 10 ^ (scientific notation)
H^+ = ____________ M
In: Chemistry
An analysis shows that 2.60 g of Titanium (Ti) combines with chlorine to form 10.31g of titanium chloride. Do all the following parts. Show all your work for for full credit. (molar mass of Ti is 47.88 g and Cl is 35.456 g)
In: Chemistry
A buffered solution containing dissolved aniline, C6H5NH2, and aniline hydrochloride, C6H5NH3Cl, has a pH of 5.47.
a) Determine the concentration of C6H5NH3+ in the solution if the concentration of C6H5NH2 is 0.200 M. The pKb of aniline is 9.13.
b) Calculate the change in pH of the solution, delta pH , if 0.393 g NaOH is added to the buffer for a final volume of 1.55 L. Assume that any contribution of NaOH to the volume is negligible.
In: Chemistry
a) Calculate the volume (in ML) of 0.170 M NaOH that must be added to 365 mL of 0.0515 M 3-(N-Morpholino) propanesulfonic acid (MOPS) to give the solution a pH of 7.55. The pKa of MOPS =7.18.
b) A buffer with a pH of 4.24 contains 0.11 M of sodium benzoate and 0.10 M of benzoic acid. What is the concentration of [H+] in the solution after the addition of 0.056 mol of HCl to a final volume of 1.6 L? Assume that any concentration of HCl to the volume is negligible.
In: Chemistry
a) Calculate the pH of resulting solution if 25.0 mL of 0.250M Hcl(aq) is added to 15.0 mL of 0.350 M NaOH (aq)
b) Determine the pH of a solution when 22.8 mL of 0.026 M HNO3 is mixed with 15.8mL of 0.0090 M HCl
In: Chemistry
1. When solid lead(II) sulfide ore burns in oxygen gas, the products are solid lead(II) oxide and sulfur dioxide gas
2PbS(s)+3O2(g)→2PbO(s)+2SO2(g)
A.How many grams of oxygen are required to react with 26.0 g of lead(II) sulfide?
B.How many grams of sulfur dioxide can be produced when 61.0 g of lead(II) sulfide reacts?
C.How many grams of lead(II) sulfide are used to produce 121 g of lead(II) oxide?
2. Pentane gas, C5H12, undergoes combustion with oxygen to produce carbon dioxide and water.
A. Write the balance equation with phases
B.How many grams of C5H12 are needed to produce 67 g of water?
C.How many grams of CO2 are produced from 26.0 g of O2?
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3. 4Al(s)+3O2(g)→2Al2O3(s) A. How many moles of O2 are needed to react with 2.50 moles of Al? B. How many grams of Al2O3 are produced when 51.8 g of Al reacts? C.When Al is reacted in a closed container with 7.46 g of O2, how many grams of Al2O3 can form? |
In: Chemistry
Molecular weight data for a polymer is tabulated here.
(a) Compute the number-average molecular weight
(b) Compute the weight-average molecular weight
(c) If it is known that this material's degree of polymerization is 710, which one of the polymers listed in Table 4.3 is this polymer? Why?
(d) After you do the calculations, consider whether you would consider this material a high molecular weight polymer and why or why not.
(e) Give one property that tends to increase with increasing molecular weight.
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Molecular Weight Range g/mol |
xi |
wi |
|
15,000–30,000 |
0.04 |
0.01 |
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30,000–45,000 |
0.07 |
0.04 |
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45,000–60,000 |
0.16 |
0.11 |
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60,000–75,000 |
0.26 |
0.24 |
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75,000–90,000 |
0.24 |
0.27 |
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90,000–105,000 |
0.12 |
0.16 |
|
105,000–120,000 |
0.08 |
0.12 |
|
120,000–135,000 |
0.03 |
0.05 |
In: Chemistry
There are three different ways to make a buffer. Which of the following is NOT one of the methods?
Select one:
a. Adding equal amounts of a strong acid and a strong base
b. Adding comparable amounts of the weak acid and its conjugate base to water
c. Adding a limited amount of strong acid to a solution of weak base
d. Adding a limited amount of strong base to a solution of weak acid
In: Chemistry
For a lab experiment, a student needs 250.00 mL of a 150 mM MES buffer (pKa = 6.27) at pH 6.50. The student is given solid MES base (MW = 217.22 g/mol), 1.25 M HCl, and 1.25 M NaOH. Describe how the student should make this buffer (including amounts to weigh or measure out). (show all your work)
In: Chemistry
To 1.0 L of a 0.31 M solution of HClO2 is added 0.14 mol of NaF.
Calculate the [HClO2] at equilibrium.
In: Chemistry
choose some virtue not discussed by Aristotle and present an Aristotelian analysis. Be sure to give a careful picture of what the virtue and its corresponding vices would look like.
In: Chemistry
The reaction is glucose with adenosine triphosphate (ATP) to form glucose 6- phosphate and adenosine diphosphate (ADP).
This reaction has a calculated equilibrium constant (K) of 1.90 × 105. What are the equilibrium concentrations of glucose and ATP if the initial concentrations of both are 0.100 M?
In: Chemistry
Draw the structure of (2R,3R)-2,3-dichloropentane. Use bold or hashed wedges to indicate the configuration at stereogenic C atoms.
In: Chemistry