Why do we use kcat (also called turnover number) and not Vmax when we characterize the properties of an enzymecatalysed reaction?
Please explain to me in details. Thank you!
In: Chemistry
Complete the following paragraph to explain the relationship between nicotinic and muscarinic cholinergic receptors
In: Chemistry
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Consider the titration of a 23.0 −mL sample of 0.180 M CH3NH2 with 0.145 M HBr. Determine each of the following. |
Part A the initial pH Express your answer using two decimal places.
SubmitMy AnswersGive Up Correct Part B the volume of added acid required to reach the equivalence point
SubmitMy AnswersGive Up Correct Part C the pH at 5.0 mL of added acid Express your answer using two decimal places.
Part D the pH at one-half of the equivalence point Express your answer using two decimal places.
Part E the pH at the equivalence point Express your answer using two decimal places.
Part F the pH after adding 5.0 mL of acid beyond the equivalence point Express your answer using two decimal places.
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In: Chemistry
Draw the lewis structures of the polyatomic ions and assign formal changes of NH4+ and CO3 2-
In: Chemistry
Explain how metal ions can form part of the structure of enzymes, and also how it can contribute to catalysis
In: Chemistry
Make 0.3M from 1M stocks. Each measurement will require 3 ml of solution in a glass test tube
a) Glucose, 0.3 M
b) Ethanol, 0.3 M (Density = 0.789g/ml and 46.1g/mol)
c) Methanol, 0.3M (0.71g/ml and 34g/mol)
d) Isopropyl alcohol 70% (0.79g/ml and 60.1 g/mol)
In: Chemistry
For determination 1:
Initial concentration for H2C2O4: 0.31 mol/L
Initial concentration for KMnO4: 0.011 mol/L
Average elapsed time: 170 seconds
Reaction rate: ??? mol/L * s
Determination 2:
Initial concentration for H2C2O4: 0.63M
Initial concentration for KMnO4: 0.011
Average elapsed time: 97 seconds
Reaction rate: ??? mol/L * s
Determination 3:
Initial concentration for H2C2O4: 0.31
Initial concentration for KMnO4: 6.022 M
Average elapsed time: 189 seconds
Reaction rate: ??? mol/L * s
What is the order of reaction with respect to:
(a) H2C2O4: ???
Overall reaction order: ???
(b) KMnO4: ???
Calculate rate constant, k, for the reaction ???
Rate equation for the reaction??
Chemistry lab on determining the effect of reactant concentrations on the reaction rate. Please help me find the reaction rate and all the questions below. Please show work!
In: Chemistry
(a) Explain why there is no distinction between low- and high-spin arrangements for an octahedral d8 metal ion. (b) Discuss the factors that contribute to the preference for forming either a high- or a low-spin d 4 complex. (c) How would you distinguish experimentally between the two configurations in (b)?
In: Chemistry
Calculate the pH for each case in the titration of 50.0 mL of 0.200 M HClO(aq)0.200 M HClO(aq) with 0.200 M KOH(aq).0.200 M KOH(aq). Use the ionization constant for HClO.
What is the pH before addition of any KOH?
pH=
What is the pH after addition of 25.0 mL KOH?
pH=
What is the pH after addition of 35.0 mL KOH?
pH=
What is the pH after addition of 50.0 mL KOH?
pH=
What is the pH after addition of 60.0 mL KOH?
pH=
In: Chemistry
Sorbic acid (HC6H7O2) is a weak monoprotic acid with Ka=1.7×10−5. Its salt (potassium sorbate) is added to cheese to inhibit the formation of mold.
What is the pH of a solution containing 11.75 g of potassium sorbate in 1.70 L of solution?
In: Chemistry
If you used the simple distillation to separate cyclohexane and toluene, will it work? Why or Why not?
In: Chemistry
The rate determining step in a reaction mechanism:
A. is the fast step
B. is the slow step
C. is always the first step
D. is the transition state
In: Chemistry
In the laboratory, a quantity of I2 was reacted with excess H2 to give 0.650 moles of HI. It is also known that the percent yield of this reaction was 46.0%. How many moles of I2 reacted? (Hint: Write a balanced equation.)
In: Chemistry
Hydrogen azide (HN3) is a shock-sensitive liquid, which means it explodes when subjected to a physical shock. The HN3 molecule contains two N-N bonds with bond lengths 113 pm and 124 pm. The H-N-N bond angle is 112°. Draw two Lewis structures of HN3 that obey the octet rule. What is the formal charge of each atom in your structures? Which structure is most consistent with the experimental data?
In: Chemistry
a)Assume the reaction 2Fe3+ + Sn2+ -> 2Fe2+ + Sn4+ has a rate law v = k[Fe3+][Sn2+]. If Fe2+ is produced at a rate of 0.12 mol L-1 s-1 when the reactant concentrations are 0.30 mol L-1 for Fe3+, and 0.40 mol L-1 for Sn2+, then what is the value of the rate constant, k ? Quote your answer to 2 decimal places.
Answer L.mol-1.s-1
b)
The half-life for the decomposition of a gaseous sample of thioketene, H2C=C=S at 500 Pa is 42 s. When the thioketene pressure is 250 Pa the half-life is 21 s. Determine the order of the reaction, entering your answer as a number.
c)
At 1100 K, acetic acid decomposes via 2 competing, first order reactions:
CH3COOH -> CH4 + CO2, k1 = 3.4 s-1
CH3COOH -> CH2=C=O + H2O, k2 = ? s-1
The half life of acetic acid at this temperature is 0.10 s. What is the value of the rate constant, k2?
d)
At 1100 K, acetic acid decomposes via 2 competing, first order reactions:
CH3COOH -> CH4 + CO2, k1 = 4.1 s-1
CH3COOH -> CH2=C=O + H2O, k2 = ? s-1
At 1100K, the yield of ketene (CH2=C=O) is 71.5%. Estimate the rate constant, k2, for the second reaction
e)
The following mechanism has been proposed for recombination of iodine atoms:
I + I -> I2*, k1 = [k1].0
I2* -> I + I, k-1 = [k-1].0
I2* + M -> I2, k2 = [k2]
What is overall rate constant if k1 = 4, k-1 = 4 and k2 = 0.04?
f)
The following mechanism has been proposed for recombination of iodine atoms:
I + I -> I2*, k1 = 9.0
I2* -> I + I, k-1 = 5.0
I2* + M -> I2, k2 = 0.04
What is overall rate constant?
.
In: Chemistry