M = n/V
.5M = n/.100 L
n = .1 L * .5M
n= .05 mols of MgCl2
mass of MgCl2 = .05 mols of MgCl2 * 95.211 grams/ 1 mol of MgCl2
mass of MgCl2 = 4.76 grams
4.76 grams of MgCl2 is needed to make 100 ml of a solution that is .500M, in chloride ion. Bolded = confused
Answer:
The bond dissociation energy to break 4 bonds in 1 mol of CH is 1644 kJ
Explanation:
Since there are 4 C-H bonds in CH₄, the bond dissociation energy of 1 mol of CH₄ is 4 × bond dissociation energy of one C-H bond.
From the table one mole is C-H bond requires 411 kJ, that is 411 kJ/mol. Therefore, 4 C-H bonds would require 4 × 411 kJ = 1644 kJ
So, the bond dissociation energy to break 4 bonds in 1 mol of CH₄ is 1644 kJ
Answer: protons and neutrons.
The nucleus is made up of 3 subatomic particles that are protons,neutrons and electrons.
General notation of an element is 
where, X is the Element, A is the Atomic Mass and Z is the Atomic Number
If we know the number of protons we can easily find out the atomic number of any element because Atomic Number = Number of protons in an element.
And in addition if we know the number of neutrons we can easily find out the atomic mass of an element because
Atomic Mass = (Number of protons) + (Number of neutrons)
If we get to know the atomic number and atomic mass, we can easily tell what element is it by looking from the periodic table.
Answer : The value of change in entropy for freezing process is, -18.07 J/mol.K
Explanation :
Formula used :

where,
= change in entropy
= change in enthalpy of fusion = 3.17 kJ/mol
As we know that:

= freezing point temperature = 
Now put all the given values in the above formula, we get:



Therefore, the value of change in entropy for freezing process is, -18.07 J/mol.K
Answer:
Melting butter
Explanation:
You can reverse the change of butter back to its original state but you can never reverse the rest back to there original state