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AveGali [126]
2 years ago
13

A certain reaction is spontaneous at temperatures below 400. K but is not spontaneous at temperatures above 400. K. If ΔH° for t

he reaction is -20. kJ mol-1 and it is assumed that ΔH° and ΔS° do not change appreciably with temperature, then the value of ΔS° for the reaction is
Chemistry
1 answer:
jeka57 [31]2 years ago
7 0

Answer:

ΔS = 0.05 kJ /mol or 50 J /mol

Explanation:

As given that the reaction is spontaneous below 400 K and non spontaneous above 400K. Thus the reaction is at equilibrium at 400 K temperature.

At equilibrium the change in free energy ΔG is zero.

The relation between free energy change, enthalpy change, entropy change and temperature is

ΔG = ΔH - TΔS

Where

ΔH = enthalpy change

T = temperature

ΔS = entropy change

at equilibrium (400 K)

ΔG = 0 = (-20) + 400XΔS

ΔS = 0.05 kJ /mol or 50 J /mol

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245 g water sample initially at at 32 oC absorbs 17 kcal of heat. What is the final temperature of water?
steposvetlana [31]

Answer:62.66°C or 235.66K

Explanation:Q=McpT, the energy was given in calories so you first convert to Joules by multiplying the value in calories by 4.184J.

17*4.184=71.128kJ.

71.128kJ=mcpT

71.128kJ=245*4.187*(T-Tm)

Tm is the final temperature of the mixture. The T is the temperature given which should be converted to Kelvin by adding 273...T=32+273=305K.

71128J=245*4.187*(305-Tm)

71128=312873.575-1025.815Tm

1025.815Tm=312873.575-71128

1025.815Tm=241745.58

Tm=241745.58/1025.815

Tm=235.66K

4 0
3 years ago
Calculate the heat required to convert 5.0 g of ice at 0.0 c to steam at 100
Fiesta28 [93]
Heat= latent heat of fusion+sensible heat+ latent heat of vapourization
=(79.7*5)+(5*100*1)+(540*5)
=3598.5 cal
6 0
3 years ago
Give an example of a balanced force.
lutik1710 [3]

Answer:

When two forces are the same strength but act in opposite direction, they are called balanced forces. Again, tug-of-war is a perfect example. If the people on each side of the rope are pulling with the same strength, but in the opposite direction, the forces are balanced. The result is no motion.

Explanation:

Hope this helps!

7 0
3 years ago
Read 2 more answers
Identify what kind of ligand (weak or strong), what kind of wavelength (long or short), what kind of spin (high spin or low spin
anzhelika [568]

To find - Identify what kind of ligand (weak or strong), what kind

              of wavelength (long or short), what kind of spin (high spin or

              low spin) and whether it is paramagnetic or diamagnetic for

              the following complexes.

              1. [Mn(CN)6]4-

              2. [Fe(OH)(H2O)5]2

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Step - by - Step Explanation -

1.

[Mn(CN)⁶]⁴⁻ :

Ligand - Strong

Wavelength - Short

Spin - Low spin

Number of unpaired electrons = 1 ∴ paramagnetic.

2.

[Fe(OH)(H₂O)₅]²⁺ :

Ligand - Weak ( both OH⁻ and H₂O )

Wavelength - Long

Spin - High spin

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3.

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Ligand - Weak ( both Br⁻ and Cl⁻ )

Wavelength - Long

Spin - High spin

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7 0
2 years ago
You have identified a substance to be solid in nature. which characteristics will justify your identification?
weeeeeb [17]
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4 0
3 years ago
Read 2 more answers
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