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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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Which of these statements is not true about chemical reaction rates? a Temperature can change a reaction rate. b The amount of r
Umnica [9.8K]

Answer:

The statement that is not true is: 'Temperature does not affect the reaction rate'.  

Explanation:

a) Temperature can change a reaction rate. <u> This is true</u>

Increasing the temperature increases the reaction rates because of the disproportionately large increase in the number of high energy collisions. It is only these collisions (possessing at least the activation energy for the reaction) which result in a reaction.

For example, the time taken to melt a metal will be much higher at a lower temperature but it will decrease as soon as we increase the temperature

b) The amount of reactants can increase the reaction rate.<u> This is true</u>

A higher concentration of reactants leads to more effective collisions per unit time, which leads to an increased reaction rate.

c) Temperature can decrease the reaction rate. <u>This is true </u>

Decreasing the temperature decreases the reaction rates because of the  decrease in the number of high energy collisions. It will result in a slower reaction.

d) Temperature does not affect the reaction rate.  <u>This is not true. </u>

The reaction rate is temperature dependent. The reaction rate increases with higher temperature and decreases with lower temperature.

4 0
3 years ago
The blank form acid compounds with hydrogen
Wewaii [24]

Answer:

The halogens form acidic compounds with hydrogen. The halogens are the most reactive among all the nonmetals

7 0
3 years ago
An atom gets over all positive charge by ____ _______
Rasek [7]
<h2>Answer:</h2>

Nucleus.

<h2>Explanation:</h2>
  • In an atom the nucleus has an overall positive charge as it contains the protons.
  • Every atom has no overall charge (neutral). While atoms do contain charged particles, they have the same number of positive protons as negative electrons( for example a sodium atom has 11 electrons which are of negative charge and 11 protons which are of positive charge).
  • These opposite charges cancel each other out making the atom neutral.

Result: Nucleus is the overall positive charge of an atom.

4 0
4 years ago
I know the paper is blurry but can anyone explain any of the questions from 76-80?
Whitepunk [10]

Answer:try to make a good pic please I have ideas about the topic

3 0
3 years ago
The notation for a particular nucleus is r3785b. in an electrically neutral atom. How many electrons are in orbit about this nuc
Serhud [2]

^{85}_{37}Rb has 37 electrons in the orbit about its nucleus.

<h3>How to write an atomic symbol with atomic mass and atomic number?</h3>

Atomic mass is the total number of neutrons and protons present in the nucleus of an element.

The atomic number is the total number of protons present in the nucleus of an element.

For writing an atomic symbol, atomic mass is written on the top left of the atomic symbol, and the atomic number is written on the downside of the left of the symbol.

^{Atomic mass}_{Atomic number}X

An electrically neutral atom is an atom that has an equal number of electrons as well as protons.

Thus from the above conclusion we can say that  ^{85}_{37}Rb has 37 electrons.

Learn more about Atomic mass and atomic number here:

brainly.com/question/3187640

#SPJ4

3 0
2 years ago
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