Answer:
Molality = 1.13 m
Explanation:
Molality is defined as the moles of the solute present in 1 kilogram of the solvent.
Given that:
Mass of 
= 26.5 g
Molar mass of = 32.04 g/mol
The formula for the calculation of moles is shown below:
Thus,
Mass of water = 735 g = 0.735 kg ( 1 g = 0.001 kg )
So, molality is:
<u>Molality = 1.13 m</u>
C i think because new info can be found to make a new idea
Answer:
Explanation:
This question seeks to test the knowledge of separation techniques.
From the narration in the question, the first separation to be done is the removal of Iron fillings by the use of magnet (magnetic separation). Since Iron is magnetic, the iron fillings will be attracted by the magnet hence removing the iron fillings from the mixture.
The second constituent to be removed will be the copper pieces by the use of a sieve (sieving). Copper pieces have relatively larger sizes than sand and common salt, hence a sieve (which separates particles based on size) can be used to remove the copper pieces from the mixture.
What will be left in the mixture after the processes above will be salt and water. This mixture will have to be dissolved in water; the salt will dissolve in water while the sand will not. After which, filtration will be done to remove the sand which will be collected on the filter paper as filtride and the salt solution will pass through the filter paper as filtrate.
The salt solution can then be evaporated to dryness to retrieve the solid salt from the solution.
The amount of salt in the mixture can then be measured using a weighing balance.
Some of safety measures to be taken during the course of this experiment includes performing the experiment in an airtight and controlled environment. Lab coat and hand gloves should be worn during the course of the experiment. The evaporation to dryness should not be done close to an inflammable material/substance
1 μL = 10^-6 L by definition
So...
82 μL = 82x10^-6 L = 8.2x10^-5 L
Beryllium Oxide has a molecular formula Be-O
% covalent character in Be-O = 100 - % ionic character in Be-O
Now,
% ionic character = {1 - exp[(-0.25)(E(Be)-E(O))²]}*100
where,
E(Be) and E(O) are the electronegativity values of Be and O
Based on the Paulings scale:-
E(Be) = 1.57
E(O) = 3.44
% ionic = {1 - exp[(-0.25)(1.57-3.44)²]}*100 = 58.28%
Therefore, % covalent = 100 -58.28 = 41.72%
Ans: b) 41 percent
