What happens when a solid is dissolved in a liquid

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

4 years ago

25)

Taya2010 [7]

Answer:

The correct answer is B) electronegativities of the bonded atoms in a molecule of the compound .

Explanation:

When two atoms forming a bond differ in their electronegativities at that time bond polarity is generated

In simple words a bond will be polar when the bonding electrons are not equally shared by two atoms.As a result the atom attract the bonding electron pair towards itself gain partial negative charge and the other atom gains partial positive charge.

For HCl is a polar compound because H and Cl atom differ in their electronegativities,as a result the bonding electron pair is not shared equally by H and Cl atoms.

8 0

3 years ago

Determine whether the given compound name or formula contains a polyatomic ion. N H 4 C l Choose... Magnesium sulfate Choose...

Morgarella [4.7K]

Answer:

NH₄Cl, Magnesium sulfate, KCN

Explanation:

Determine whether the given compound name or formula contains a polyatomic ion.

NH₄Cl. YES. It contains the polyatomic ion ammonium NH₄⁺.

Magnesium sulfate. YES. It contains the polyatomic ion sulfate SO₄²⁻.

Sodium phosphide Na₃P. NO.

SO₃. NO.

Calcium hydroxide Ca(OH)₂. NO.

KCN. YES. It contains the polyatomic ion cyanide CN⁻.

4 0

3 years ago

As a pendulum swings from its highest to its lowest position along an arc, what happens to its kinetic energy and potential ener

lara31 [8.8K]

C.

Explanation:

As a pendulum swings from its highest to its lowest position along an arc, what happens to its kinetic energy and potential energy? The potential energy decreases while the kinetic energy increases.

4 0

3 years ago

How many grams of zinc would be required to produce 9.65g of zinc hydroxide

Effectus [21]

The question is incomplete, here is the complete question:

How many grams of zinc would be required to produce 9.65g of zinc hydroxide

Zn+2MnO₂+H₂O→Zn(OH)₂+Mn₂O₃

<u>Answer:</u> The mass of zinc required is 6.35 grams

<u>Explanation:</u>

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)