Answer:
Option D
Oxygen particles mix evenly with hydrogen particles.
Explanation:
Diffusion refers to the movement of gasses from a region of higher concentration to a region of lower concentration.
Diffusion occurs in gases because their particles are in a state of constant random motion.
Due to this continuous random motion, once the oxygen and the hydrogen are added to the container, they will begin to mix freely with each other until they fill up the entire volume of the container.
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 : 
For non-spontaneous reaction : 
We can find the temperature using the formula for Gibbs free energy which is:
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'
Since reaction should be spontaneous that means 
should be negative , so the above formula can be written as :
On rearranging the above formula we get :
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.
Answer: When a substance is pure, it is composed of one type of molecule. For example, table salt is only composed of (more or less) salt molecules, while seawater has water and salt molecules. A more complicated example of a non - pure substance is soil. It has many different types of nutrients and compounds.
Answer:
ΔHrxn = 178.3 kJ/mol
Explanation:
Using Hess's law, you can obtain ΔHrxn from ΔHf of products and reactants, thus:
<em>Hess's law: </em>
ΔHrxn = <em>∑nΔHf products - ∑nΔHf reactants</em>
<em>Where n are moles of reaction</em>
<em> </em>
Thus, from the reaction:
CaCO₃(s) → CaO(s) + CO₂(g)
ΔHrxn = <em>ΔHf </em>CaO(s)<em> + ΔHf </em>CO₂(g)<em> - ΔHf </em>CaCO₃(s)
ΔHrxn = -635.1kJ/mol + (-393.5kJ/mol) - (-1206.9kJ/mol)
<em>ΔHrxn = 178.3 kJ/mol</em>
