Questions
Explain how metal ions can form part of the structure of enzymes, and also how it...

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...

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...

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...

(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...

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...

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...

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...

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...

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...

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 =...

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

1. Describe how you would prepare 1.50 L of a 0.500 M phosphate buffer with a...

1. Describe how you would prepare 1.50 L of a 0.500 M phosphate buffer with a pH of 7.5. (show work)

2. If 5.00 mL of 0.150 M HCl is added to 0.750 L of your buffer from (1), what will the new ph be? (show work)

3. If 10.00 mL of 1.50 M NaOH is added to 0.750 L of your buffer from (1), what will the new ph be? (show work)

In: Chemistry

One facet of the central field approximation for many-electron atoms is that inner-shell electrons screen the...

One facet of the central field approximation for many-electron atoms is that inner-shell electrons screen the nuclear charge. To understand how this works quantitatively, first note that the probability distributions for electrons in different shells generally do not overlap much. For instance, the electrons in the M shell (n=3) are almost always farther from the nucleus than the electrons of the K (n=1) and L (n=2) shells. Thus, it is a good approximation to assume that the inner shells completely screen the nucleus from the outer shells. For example, if there are ten electrons altogether in the K and L shells of an atom, then the electrons in the M shell experience force from a charge of roughly Z−10, where Z is the charge on the nucleus as an integer multiple of e, the magnitude of the charge on an electron. This is called the effective nuclear charge Zeff. Part A In a beryllium atom (Z=4), how many electrons are in the K shell? Part B In xenon (Z=54), what is the effective charge Zeff experienced by an electron in the M (n=3) shell? Part C How many electrons are there altogether in the K, L, and M shells of xenon? Recall that for n=3, the orbital quantum number l must be zero, one, or two and that ml can take any value between postive and negative l. Part D The energy for the 5p valence electron in indium (Z=49) is −5.79 electron volts. What is the effective nuclear charge Zeff experienced by this electron?

In: Chemistry

1)Use the balanced chemical equation below to calculate the mass of KCl that is formed for...

1)Use the balanced chemical equation below to calculate the mass of KCl that is formed for every 164 L of O2(g) produced. You may assume the reaction takes place at STP.

2 KClO3(s) → 2 KCl(s) + 3 O2(g)

2)Identify the limiting reactant and calculate the theoretical yield of CO2(g), in grams, if 21.5 L of C3H8(g) reacts with 96.1 L of O2(g) according the the balanced chemical equation below.

C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g)

In: Chemistry

2,3 BPG is quite abundant in red blood cells (~4.5 mM) and it modulates the affinity...

2,3 BPG is quite abundant in red blood cells (~4.5 mM) and it modulates the affinity of hemoglobin for oxgen. Briefly explain what BPG is doing to the affinity of hemoglobin for oxygen.

In: Chemistry