Use the generalized reaction mechanism of photochemical smog formation to explain why aldehydes start at a very low concentration, build up in concentration until about 2:00 p.m. in the afternoon, and then decrease to their original concentrations?
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37.0mL of NaOH is required to titrate 70.0mL of 0.155M H3A to the volume where pH=pKa2. What is the molarity of the titrant?
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You are a scientist at a reputable lab researching how different polyprotic acids affect the pH of a solution. How many equivalence points would be visible on the titration curve if you fully titrated a given a solution of 1.0 M sulfurous acid (H2SO3)?
A buffer is made by adding 0.600 mol HC2H3O2 and 0.600 mol NaC2H3O2 to enough water to make 4L of solution. The pKa of the buffer is 4.74. Calculate the pH of solution after 0.035 mol of NaOH is added. (assume the volume doesn
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How the DNA was extracted from the strawberries, what was the purpose of the soap and salt?
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N2 + 3H2>>>2NH3
Using the equation above, calculate how many grams of NH3 you would have if you started with 2.37 g of N2 and 2.37 g of H2?
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Calculate the value of Eocell for the following reaction: 2Co3+(aq) + 3Ca(s) --> 2Co(s) + 3Ca2+(aq) Co3+(aq) + 3e– --> Co(s) Eo = 1.54 V Ca2+(aq) + 2e– --> Ca(s) Eo = –2.87 V.
A. –1.33 V
B. +1.33 V
C. –4.41 V
D. –11.6 V
E. +4.41 V
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Why do we use atomic absorption spectroscopy?
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What equations are/can be used to describe the velocity profile for a turbulet flow in a pipe and how do you visualise the plot in excel?
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Imagine that you are attempting to determine the concentration of an acid by titration with a solution of sodium hydroxide with a known concentration, using phenolphthalein as an indicator. For each of the following sources of error, indicate whether the calculated concentration of acid would be too high or too low.
i. An air bubble was present in the tip of the buret before beginning the titration but was absent at the end of the titration.
ii. You added too much base and went beyond the end point.
iii. Some of the acid splashed on to the sides of the flask and wasn’t titrated.
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Describe the kinetic differences between an uncatalyzed second order chemical reaction and an enzyme catalyzed reaction.
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Which statement is NOT correct?
A. You can increase entropy and still have a spontaneous reaction.
B. If there is a decrease in the energy of the system, the reaction is spontaneous.
C. Spontaneous reactions will tend to maximize entropy and minimize enthalpy at given temperature
D. Entropy can drive a reaction that is strongly endothermic
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How long will it take to plate 1.25 grams of Copper metal from a solution of CuSO4, if a current of 2.0 A is used? Assume 100% efficiency.
In: Chemistry
Part A
Which of the following ionic compounds is expected to have the highest lattice energy?
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KI |
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NaCl |
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NaF |
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MgO |
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BaS |
Part B
Which of the following atoms could form a fluoride compound (i.e. MFn) in which M has an "expanded octet" (more than an octet on the centrat atom)?
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C |
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P |
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Be |
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O |
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H |
Part C
Which of the elements below, when found in a covalently bonded compound, could have an incomplete octet (have less than a full octet of electrons) and still have a valid Lewis Structure?
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B |
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C |
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P |
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S |
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Br |
In: Chemistry
21.83 mL of a Pb2 solution, containing excess Pb2 , was added to 10.75 mL of a 2,3-dimercapto-1-propanol (BAL) solution of unknown concentration, forming the 1:1 Pb2 –BAL complex. The excess Pb2 was titrated with 0.0141 M EDTA, requiring 8.86 mL to reach the equivalence point. Separately, 40.70 mL of the EDTA solution was required to titrate 31.00 mL of the Pb2 solution. Calculate the BAL concentration, in molarity, of the original 10.75-mL solution.
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Classify the reaction Ca(OH)2 (aq) + H2CO3(aq) → CaCO3(s) + 2
H2O(l):
a. Acid-Base b. Precipitation c. Both d. Neither
Sodium phosphate reacts with calcium chloride. Write the balanced,
net ionic equation, and then choose the coefficient associated with
the calcium ion in that equation (choose 0 if not present):
a. 0 b. 1 c. 2 d. 3
Sulfuric acid reacts with barium hydroxide. Write the balanced, net
ionic equation, and then choose the coefficient associated with the
hydroxide ion in that equation (choose 0 if not present):
a. 0 b. 1 c. 2 d. 3
Sulfuric acid reacts with ammonia. Write the balanced, net ionic
equation, and then choose the coefficient associated with the
sulfate ion in that equation (choose 0 if not present):
a. 0 b. 1 c. 2 d. 3
Please show any work
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