Answer:
0.404M
Explanation:
...<em>To make exactly 100.0mL of solution...</em>
Molar concentration is defined as the amount of moles of a solute (In this case, nitrate ion, NO₃⁻) in 1 L of solution.
To solve this question we need to convert the mass of Fe(NO₃)₃ to moles. As 1 mole of Fe(NO₃)₃ contains 3 moles of nitrate ion we can find moles of nitrate ion in 100.0mL of solution, and we can solve the amount of moles per liter:
<em>Moles Fe(NO₃)₃ -Molar mass: 241.86g/mol-:</em>
3.26g * (1mol / 241.86g) =
0.01348 moles Fe(NO₃)₃ * (3 moles of NO₃⁻ / 1mole Fe(NO₃)₃) =
<em>0.0404 moles of NO₃⁻</em>
In 100mL = 0.1L, the molar concentration is:
0.0404 moles of NO₃⁻ / 0.100L =
<h3>0.404M</h3>
Using dimensional analysis, we can find the moles of strontium by comparing the mass of strontium to it's atomic mass.
You can find the atomic mass of Sr on the periodic table:
Atomic Mass Sr = 87.62g/mol
In case you are not familiar, dimensional analysis works like this:
(what we know) x (conversion factor) = what we are looking for
The conversion factor compares the units of what we know to the units of what we are looking for. In this case, the conversion factor is:
1 mol/87.62g
The important thing to note about the conversion factor is that you want to be able to cancel out the units of your given measurement (in this case, it is the mass)
So, our full solution will be:
moles Sr = (175.24 g)x(1 mol/87.62 g)
(cancel out the mass units)
moles Sr = 175.24 x 1 mol/87.62
= 2.00 mol Sr
Hope this helped you!
Answer:
The gases will expand until a volume of Vf= 10812 cm^3
Explanation:
Since the gas mixture is expanding at constant pressure
and therefore
knowing that 1 torr=133,32 Pa
therefore
Answer:
The answer is 4.28 moles
Explanation:
This is super easy okay, you won't forget this!
Basically mole ratios, we're just looking at the coefficients in front of the compounds, multiplying them, and dividing them as we see fit.
In this example, you can see how you need 2 moles of lithium bromide (LiBr) for the reaction, and 2 moles of lithium chloride (LiCl) will be produced.
Basically, the <u>molar ratio</u> is when you divide numbers and see how much of this do I have for that (if that makes sense).
So if you were to divide the 2 moles of LiBr / 2 moles of LiCl = 1. So we know that the mole ratio for LiBr to LiCl is 1:1 or 2:2, either or, it's the same thing.
SO THE BIG IDEA, if we have 4.28 moles of lithium bromide reacting, we should also have 4.28 moles of lithium chloride produced, BECAUSE the <u>mole ratio</u> is 1:1.
I hope this makes sense please tell me if it doesn't, I will try my best to explain a little more.
Explanation:
The given data is as follows.
Refractive index of mixture = 1.456
Refractive index of hexane = 1.375
Refractive index of toulene = 1.497
Let mole fraction of hexane =
and, mole fraction of toulene =
Also,
or,
Hence, calculate the mole fraction of hexane as follows.
refractive index mixture= mole fraction hexane × ref index hexane + mole fraction toluene × ref index toluene.
1.456 =
1.456 =
0.081 =
=
= 0.66
Since,
= 1 - 0.66
= 0.34
Thus, we can conclude that mole fraction of hexane in your sample is 0.34.