Answer:
The answer to your question is: 0.05 M
Explanation:
I'm not sure about the units umol, I think is units mol.
Data
MgF2 = 0.0191 mol
Volume = 400 ml
Molarity = moles / volume
Molarity = 0.0191 / 0.4 l
Molarity = 0.048 ≈ 0.05 M
Answer: Hsub=Hfus+Hvap
Explanation:
The molar heat of vaporization measured in kilojoules per mole, or kJ/mol is the energy needed to make vapor one mole of a liquid. .
The molar heat of sublimation measured in kilojoules per mole, or kJ/mol is the energy needed to sublime one mole of a solid,
the molar heat of fusion measured in kilojoules per mole, or kJ/mol is the energy needed to melt one mole of a solid.
Hess law helps to explain the relationship in physical chemistry stating that the total enthalpy change during the complete course of a reaction is the same whether the reaction is made in one step or in several steps.
In this context Hess’s law helps to see the several steps involved as the heat of sublimation energy is equal to the sum of vaporization energy and fusion energy.
You have to google the answers
Answer:
6.05 g
Explanation:
Molarity of a substance , is the number of moles present in a liter of solution .
M = n / V
M = molarity
V = volume of solution in liter ,
n = moles of solute ,
From the question ,
M = 200mM
Since,
1 mM = 10⁻³ M
M = 200 * 10⁻³ M
V = 250 mL
Since,
1 mL = 10⁻³ L
V = 250 * 10⁻³ L
The moles can be calculated , by using the above relation,
M = n / V
Putting the respective values ,
200 * 10⁻³ M = n / 250 * 10⁻³ L
n = 0.05 mol
Moles is denoted by given mass divided by the molecular mass ,
Hence ,
n = w / m
n = moles ,
w = given mass ,
m = molecular mass .
From the question ,
m = 121 g/mol
n = 0.05 mol ( calculated above )
The mass of tri base can be calculated by using the above equation ,
n = w / m
Putting the respective values ,
0.05 mol = w / 121 g/mol
w = 0.05 mol * 121 g/mol
w = 6.05 g
