<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.
<u>Answer</u>:
Electric evaporator has been used to clean up the Chernobyl and 3 mile island accident.
<u>Explanation</u>:
About 14 years back, there was a puff of radioactive steam from the evaporator used in the "Three-mile island" nuclear plant. It took two years for the electric evaporator to clean up the 2.2 million gallons of water that have been destroyed because of the nuclear power plant accident.
The steam that came out of the electric evaporator carried a radioactive form of hydrogen and tritium with itself. Cost of clean up was $1 billion.
There are spaces between particles of matter. The average amount of empty space between molecules gets progressively larger as a sample of matter moves from the solid to the liquid and gas phases. There are attractive forces between atoms/molecules, and these become stronger as the particles move closer together.
Explanation:
Advantages of Common Names
The main advantage of using common plant names is ease of usage and common understanding in certain geographical areas and, conversely, the prevention of confusion among the laymen who do not understand Latin
.What are the disadvantages of common names?
These names may not be same every where in all places so in order to have universally similar name.
Creates confusion among different languages.
Cannot identify one particular species by common names.
