<span>The student should
follow following steps to make 1 L of </span>2.0 M CaCl₂.<span>
<span>
1. First he should
calculate the number of moles of 2.0 M CaCl</span></span>₂ in 1 L solution.<span>
</span>Molarity of the solution = 2.0 M<span>
Volume of solution which should be prepared = 1 L
Molarity =
number of moles / volume of the solution
Hence, number of moles in 1 L = 2 mol
2. Find
out the mass of dry CaCl</span>₂ in 2 moles.<span>
moles =
mass / molar mass
Moles of CaCl₂ =
2 mol</span><span>
Molar mass of CaCl₂ = </span><span>110.98 g/mol
Hence, mass of CaCl</span>₂ = 2 mol x <span>110.98 g/mol
= 221.96
g
3. Weigh the mass
accurately
4. Then take a cleaned and dry1 L volumetric flask and place a funnel top of it. Then carefully add the salt into the volumetric flask and
finally wash the funnel and watch glass
with de-ionized water. That water also should be added into the volumetric
flask.
5. Then add some
de-ionized water into
the volumetric flask and swirl well until all salt are
dissolved.
<span>6. Then top up to
mark of the volumetric flask carefully.
</span></span>
7. As the final step prepared solution should be labelled.
In finding the molarity of a solution, we use the following formula:

What is Molarity?
The number of moles of the solute is calculated by dividing the mass of the solute by its molar mass.
<h3 />
The molar mass of NH4NO3 and (NH4)3PO4 are 80.043 g/mol and 149.0867 g/mol, respectively.




![[NH+4]=0.1596 mol20.0 L=7.98×10−3 M NH+4](https://tex.z-dn.net/?f=%5BNH%2B4%5D%3D0.1596%20mol20.0%20L%3D7.98%C3%9710%E2%88%923%20M%20NH%2B4)
![[PO3−4]=0.0296 mol20.0 L=1.48×10−3 M PO3−4](https://tex.z-dn.net/?f=%5BPO3%E2%88%924%5D%3D0.0296%20mol20.0%20L%3D1.48%C3%9710%E2%88%923%20M%20PO3%E2%88%924)
Therefore,
has a molarity of 
To learn more about Molarity click on the link below:
brainly.com/question/19943363
#SPJ4
Answer:
-32 Fahrenheit converts to 237.594 Kelvin
Answer:
400 mL
Explanation:
Given data:
Mass of barium = 2.17 g
Pressure = 748 mmHg (748/760 = 0.98 atm)
Temperature = 21 °C ( 273+ 21 = 294k)
Milliliters of H₂ evolved = ?
Solution:
chemical equation:
Ba + 2H₂O → Ba(OH)₂ + H₂
Number of moles of barium:
Number of moles = mass/ molar mass
Number of moles = 2.17 g / 137.327 g/mol
Number of moles = 0.016 mol
Now we will compare the moles of barium with H₂.
Ba : H₂
1 : 1
0.016 : 0.016
Milliliters of H₂:
PV = nRT
V = nRT/P
V = 0.016 mol × 0.0821 atm. mol⁻¹.k⁻¹.L×294 k/0.98 atm
V = 0.39 atm. L/0.98 atm
V = 0.4 L
L to mL
0.4 × 1000 = 400 mL