In: Chemistry
Aspirin is produced by the reaction of salicylic acid (C7H6O3 . M = 138.1 g/mol) and acetic anhydride(C4H6O3, M = 102.1 g/mol).
C7H6O3(s) + C4H6O3(l) → C9H8O4(s) + C2H4O2(l)
If 2.04 g of C9H8O4 (M = 180.2 g/mol) is produced from the reaction of 3.00 g C7H6O3 and 5.40 g C4H6O3, what is the percent yield?
In: Chemistry
Carbon monoxide at 25C and saturated steam at 150C are fed to a continuous water-shift reactor. The product gas, which contains 40.0 mole% H2, 40.0 mole% CO2 and the rest H2O(v) emerges at 500C at a rate of 3.5 SCMH, and goes to a condensor, where all of the H2O is condensed. The gas and liquid streams leaving the condensor are at equilibrium at 15C and 1 atm. The liquid leaving the condensor can be assumed to be pure water (no dissolved gases).
a) Calculate the % excess steam fed to the reactor and rate of condensation of the water (kg/h).
b) Calculate the rate (kW) at which heat must be removed from the condensor.
c) Taking atomic species at 25C as references, prepare and fill in an inlet-outlet enthaply table and calculate the required heat rate of heat transfer (kW) to or from the reactor.
In: Chemistry
A student ran two separate substitution reactions, Reaction A and Reaction B, in lab that utilized an alkyl halide and a nucleophile. However, he did not know if the reactions proceeded through an SN1 or SN2 mechanism. To determine the mechanism for both reactions, the student increased the concentration of the nucleophile in Reactions A and B. The rate of reaction for Reaction A increased. The rate of reaction for Reaction B remained the same.
(a) Which reaction is the SN1 reaction? (1 pt)
(b) Which reaction is the SN2 reaction? (1 pt)
(c) Explain both of your choices. (4 pts)
In: Chemistry
Solve an equilibrium problem (using an ICE table) to calculate the pH of each of the following solutions.
a) 0.13 mol*L−1 CH3NH2
b) 0.13 mol*L−1 CH3NH3Cl
c)a mixture that is 0.13 molL−1 in CH3NH2
and 0.13 molL−1 in CH3NH3Cl
In: Chemistry
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In: Chemistry
The combustion of liquid ethanol (C2H5OH) produces carbon dioxide and water. After 4.61 mL of ethanol (density=0.789g/ml) was allowed to burn in the presence of 15.70 g of oxygen gas, 3.71 mL of water (density=1.00g/ml) was collected. Determine the theoretical yield of H2O for the reaction. Determine the percent yield of H2O for the reaction.
In: Chemistry
An enzymatic reaction was analyzed for rate versus substrate concentration. Roughly estimate the Vmax and Km from these measurements. (Hint: Slope = rise/run and remember what Km represents!)
vo(nM/s) [S] (nM)
30 100,000
29.5 10,000
29 1,000
28 200
25 150
20 100
10 50
5 20
a. Vmax = 10 nM/s, Km = 20 nM
b. Vmax = 20 nM/s , Km = 50 nM
c. Vmax = 40 nM/s , Km = 150 nM
d. Vmax = 70 nM/s, Km = 250 nM
ANSWER is (c), how?
In: Chemistry
Determination of an Equilibrium Constant
1. What is meant by a reversible reaction?
2. True or False : The
numerical value of the equilibrium constant for
a given reaction only changes
if the temperature
changes.
3. Which component of the reaction mixture was it
that was titrated with
sodium hydroxide?
A. Acetic acid B. Isopropyl alcohol
C. Water D. Phenolphthalein
4. Why was it necessary to wrap your rubber stopper in plastic wrap?
5. Why was it necessary to titrate a blank sample
solution, that is, a sample
of distilled water which contain only sulfuric
acid?
6. List two advantages of using a buret for measuring
reaction volumes as
opposed to maybe a graduated cylinder. (Precision and accuracy are
not exceptable answers)
7. What is a catalyst and how and why was a catalyst
needed in this
experiment?
8. When would you want to use a pipet instead of a
buret in an experiment?
In: Chemistry
Chemical Engineering Question
100 mol/minute of propane gas is burned completely in a continuous reactor with air to form carbon dioxide and water. Develop an Excel spreadsheet to calculate the adiabatic flame temperature if the gasses are fed at 30oC, 1atm for the following cases:
% Excess Air = 0%, +10%, +25%, +50%, +75%, +100%, +150%, +200%
Use heat capacity data from Table B.2 for all components in the combustion reaction.Turn in a hard copy of the Excel spreadsheet as well as a plot of adiabatic flame temperature vs.% excess air.
In: Chemistry
Please post a detailed explaination:
Compare and contrast the actions of ribonuclease and restriction enzymes as to substrate choice and mechanism. Show how their strategies are similar, but also why they must use different strategies.
In: Chemistry
Please use the values in the resources listed below instead of the textbook values.
Balance the following in acidic solution. (Omit states-of-matter from your answer. Use the lowest possible whole number coefficients.)
(a)
Ti + Cr2O72− → Ti3+ + Cr3+
Oxidation reaction
_________________
Reduction reaction
_________________
Net reaction
_________________
(b)
H2O2 + Mo2+ → H2O + Mo4+
Oxidation reaction
_________________
Reduction reaction
_________________
Net reaction
_________________
(c)
Hg + SnO2 → Hg22+ + Sn2+
Oxidation reaction
_________________
Reduction reaction
_________________
Net reaction
_________________
In: Chemistry
A 4.50 mL sample of a 0.100 M solution of an aromatic hydrocarbon dissolved in hexane is excited with a flash of light. The aromatic compound emits 19.3 J of energy at an average wavelength of 379 nm. What percentage of the aromatic compound molecules emitted a photon? Please Help, Thanks
In: Chemistry
How many grams of sodium lactate (MW = 112 g/mol) are required to prepare 200 ml solution at 1.0 M? Given pKa of lactic acid = 3.86, what is the pH of this solution?
In: Chemistry
If the Kb of a weak base is 3.8 × 10-6, what is the pH of a 0.39 M solution of this base?
In: Chemistry