<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.
Answer:
A physical change, such as a state change or dissolving, does not create a new substance, but a chemical change does. In a chemical reaction, the atoms and molecules that interact with each other are called reactants. In a chemical reaction, the atoms and molecules produced by the reaction are called products.
Answer:
74.6 g
Explanation:
The computation of the number of grams produced at the time when 32.0 grams of C react is shown below:
As we know that
But before that we need to find out the moles of c i.e carbon which is
= 2.66 mol
As we know that
1 mol of C produces 1 mol of CO
So, for 2.66 mol, the mass of CO is
= 74.6 g
Basically we applied the above equation so that we can reach to the answer
Answer:
A theory doesn’t change into a scientific law because of new or better evidence.
Explanation:
A theory will always remain a theory, and i law will remain a law. The reason being that theories and laws may differ on account of newfound countervailing evidence. Remember, theories and laws are very different from hypotheses.
Answer:
Explanation: Catalysis is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst. Catalysts are not consumed in the reaction and remain unchanged after it.
