Which statement about the self-ionization of water is correct?

The protein lysozyme unfolds at a transition temperature of 75.5°C, and the standard enthalpy of transition is 509 kJ mol-1. Cal

spin [16.1K]

Answer:

0.4774 KJ/K.mol

Explanation:

We are told that the transition at 25.0°C occurs in three steps. Steps i, ii and iii.

Thus;

the entropy of unfolding of lysozyme = ΔS_i + ΔS_ii + ΔS_iii

Now,

C_p,m(unfolded protein) = C_p,m(folded protein) + 6.28 kJ/K.mol

Now, for the first process, ΔS_i is given as;

ΔS_i = C_p,m × In(T2/T1)

We are given;

T1 = 25°C = 25 + 273.15K = 298.15 K

T2 = 75.5°C = 75.5 + 273.15 K=348.65 K

Thus;

ΔS_i = C_p,m × In(348.65/298.15)

Now, for the third process, ΔS_iii is given as;

ΔS_iii = (C_p,m + 6.28 kJ/K.mol) × In(T1/T2)

Thus;

ΔS_iii = (C_p,m + 6.28 kJ/K.mol) × In(298.15/348.65)

Now, we don't know C_pm. So, we have to find a way to eliminate it. We will do it by rewriting In(298.15/348.65) in such a way that when ΔS_iii is added to ΔS_i, C_p,m will cancel out. Thus;

In(298.15/348.65) can also be written as;

In(348.65/298.15)^(-1) or

- In(348.65/298.15)

Thus;

ΔS_iii = - [(C_p,m + 6.28 kJ/K.mol) × In(298.15/348.65)]

Now, let's add ΔS_iii to ΔS_i to get;

ΔS_i + ΔS_iii = [C_p,m × In(348.65/298.15)] + [(-C_p,m - 6.28 kJ/K.mol) × In(348.65/298.15)]

ΔS_i + ΔS_iii = [C_p,m × In(348.65/298.15)] - [C_p,m × In(348.65/298.15)] - [6.28In(348.65/298.15)]

First 2 terms will cancel out to give;

ΔS_i + ΔS_iii = -6.28In(348.65/298.15)

ΔS_i + ΔS_iii = -0.9826 KJ/K.mol

Now,for process ii;

ΔS_ii = standard enthalpy of transition/Transition Temperature

Thus;

ΔS_ii = (509 KJ/K.mol)/348.65

ΔS_ii = 1.46 KJ/K.mol

Thus;

the entropy of unfolding of lysozyme = ΔS_i + ΔS_ii + ΔS_iii = -0.9826 + 1.46 = 0.4774 KJ/K.mol

5 0

3 years ago

a propane torch is lit inside a hot air balloon during preflight preparations to inflate the balloon. which condition of the gas

earnstyle [38]

Answer:

The pressure remains constant

Explanation:

this is an example in charles law where as the temperature increases so does the volume.

5 0

3 years ago

Read 2 more answers

The most important ore of aluminum is _____ show the chemical formula .

3241004551 [841]

Answer:

The most important ore of aluminum is<u> Bauxite.</u>

And its chemical formula is $Al_2O_3.2H_2O$ .

Explanation:

Bauxite is the most important ore of Aluminium from which Aluminium is extracted. Bauxite is a rock and composed of Aluminium bearing mineral.

And its chemical formula is $Al_2O_3.2H_2O$ .

It contains Gibbsite, Bohmite and Diaspore along with iron.

It is a soft material with somewhat white to grey to reddish brown in colour.

It has an earthy lustre and low specific gravity.

<u />

5 0

4 years ago

Iron (III) bromide reacts with sodium hydroxide to produce iron (III) hydroxide and sodium bromide. Write the balanced chemical

valkas [14]

3 NaOH + FeBr3 = 3 NaBr + Fe(OH)3

Hope this helps!!

3 0

3 years ago

Silver was precipitated and collected by filtration. The experiment yielded .077g of silver after dying. The predicted yield was

PSYCHO15rus [73]

Answer:

Precentage error = 7.23%

Explanation:

The precentage error formula is the useful method for determining precision of your experimental result

It can be calculated using :

$percent\ error = |\frac{experimental\ value-predicted\ value} {predicted\ value}|\times 100$

$percent\ error = |\frac{0.077\ -0.083} {0.083}|\times 100$

So we get percentage error = 7.23%

Precision means how close the experimental value to the true value or theoretical value

If percentage error is large it means experimental results are deviated and there is need to check mistakes,imprecision in the experiment

If the percentage error is zero it means the experiment is perfectly done without inaccuracy

4 0

3 years ago