If you were to start with 20 g of this isotope, how much would be left after 800 days? Show your work

At which temperature would a reaction with H -92 kJ/mol, S -0.199 kJ/(mol-K) be spontaneous? A.600k B.500k C.400k D.700k

stiv31 [10]

Given information : H = -92 KJ/mol and S = -0.199 KJ/(mol.K)

At equilibrium G = 0

We have to find the Temperature at which reaction would be spontaneous.

For spontaneous reaction : $\triangle G = negative (-)$

For non-spontaneous reaction : $\triangle G = positive (+)$

We can find the temperature using the formula for Gibbs free energy which is:

$\triangle G = \bigtriangleup H - T\bigtriangleup S$

Where, G = Gibbs free energy ,

H = Enthalpy

S = Entropy

T = Temperature

By plugging the value of G , H and S in the above formula we can find 'T'

$\triangle G = \bigtriangleup H - T\bigtriangleup S$

Since reaction should be spontaneous that means $\triangle G$ should be negative , so the above formula can be written as :

$\triangle G < \bigtriangleup H - T\bigtriangleup S$

On rearranging the above formula we get :

$0 < \bigtriangleup H - T\bigtriangleup S$

$T < \frac{\bigtriangleup H}{\bigtriangleup S}$

$T < \frac{-92\frac{KJ}{mol}}{-0.199\frac{KJ}{mol.K}}$

$T < (\frac{-92}{-0.199})\times (\frac{KJ}{mol})\times (\frac{mol.K}{KJ})$

$T < 462.3 K$

For the reaction to be spontaneous , T should be less than 462.3 K, so out of given option , C is correct which is 400 K.

8 0

3 years ago

Read 2 more answers

Cobalt-59 is a stable isotope and cobalt-60 is an unstable or radioactive isotope. These two isotopes differ in the number of -

pogonyaev

Cobalt-59 and Cobalt-60 differ in that they have different mass number which means they have different number of neutrons. Isotopes are atoms of the same element with similar atomic number but different mass number. Cobalt-60, has a number of uses, which includes, being used to irradiate food sources as a method of preserving food, used in industrial radiography to detect structural flaws in metal parts among other uses.

7 0

4 years ago

Which type of bond? CF4 Ionic or covalent ??

ZanzabumX [31]

Answer:

Covalent bobd

Explanation:

Chamical bonding between non metals is covalent.

7 0

3 years ago

What is the chsrge of am atom with an equal number of protons and electrons

BabaBlast [244]

Answer:

0

Explanation:

they cancel each other out (ex: 1 positive and 1 negative cancels, making it neutral or a charge of 0)

5 0

2 years ago

A student went to the dentist and found out that he had a cavity. He always brushes his teeth twice a day, so he didn't understa

Free_Kalibri [48]

Answer:

The drinks that the student should avoid - if he wants to avoid damage to his teeth - are drinks C and E, since they are acidic, according to their pH.

Explanation:

pH measures the acidity or alkalinity of a solution, taking into account the amount of hydrogen ions present in it, and established on a scale that goes from 0 to 14.

In chemistry, pH is derived from the formula that indicates:

pH = - Log₁₀ αH⁺ , where α is the activity of hydrogen ions.

A solution with a pH of 7 is considered neutral, above this value it is an acidic solution and below this value it is called acidic.

According to this:

Acidic drinks are: drink C (5.3) and E (2.4).
The basic drinks are: drink A (11.9) and drink D (9.8).
The neutral drink is the drink B (7), which corresponds to water.

4 0

3 years ago