<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.
-19.15 degrees Celsius. 254k-273.15=-19.15
You have to subtract 273
Answer:
To interpret a 13C-NMR spectrum we will use some standards very simple. A 13C-NMR spectrum gives us the following information:
1. Indicates the number of non-equivalent carbons in the molecule.
2. Measuring the chemical shift we can intuit the environment
electronic and determine the next functional groups.
3. In this case we cannot count on integration since the different
carbons have different relaxation times.
The number of peaks in the spectrum indicates the number of types of carbon present in the analyzed substance.
The factors that influence the chemical shift of the signals in the 13C NMR are:
- electronegativity of carbon bound groups
-
carbon hybridization
Explanation:
The nuclear magnetic resonance of C13 is complementary to that of H1. This technique is used to determine the magnetic environment of carbon atoms.
