The molality of a 0.677 m ethanol ( c 2 h 5 o h ) solution whose density is 0.588 g/ml.
What is molality and molarity?
The number of solvent moles per kilogram is known as molality. Because the mass of the solute and solvent in the solution remains constant, molality is the preferred concentration transfer method.
Molarity, also referred to as molar concentration, is the quantity of a material expressed as moles per litre of solution. Solutions marked with a molar concentration have a capital M. One mole of solvent per litre is present in a 1.0 M solution.
Molar mass (w) of C2H5OH = 46g
Molarity(M) = 0.677M
Density(D) = 0.588g/mol
<u>Molality(m)</u><u> = M/D * (1000 + w*M)</u>
<u>= 1187.2m</u>
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Correct question: A tool used for vegetable strainer,it is essential for various tasks from cleaning vegetables to straining pasta or tin contents.
Answer: The tool is called COLANDER.
Explanation:
In the kitchen, there are different types of equipments and utensils which makes work easier and faster. Examples of such equipment/ utensils includes:
--> graters,
--> cutleries ( spoon, fork, knife)
--> colanders
--> Pots
--> Blenders
These utensils are made up of rubber, plastics, wood, ceramics and stainless steel.
A Colander is an important kitchen utensil, a type of strainer with perforated holes. The holes allows fluid to drain leaving behind the solid part. It is usually bowl - shaped. It helps in performing the following roles in the kitchen:
--> cleaning vegetables
--> straining of pasta
--> straining of tin contents
Colanders are usually made of stainless steel, plastics and ceramics.
1) we calculate the molar mass of He (helium) and Kr (Krypton).
atomic mass (He)=4 u
atomic mas (Kr)=83.8 u
Therefore the molar mass will be:
molar mass(He)=4 g/mol
molar mass(Kr)=83.8 g/mol.
1) We can find the next equation:
mass=molar mass x number of moles.
x=number of moles of helium
y=number of moles of helium.
(4 g/mol) x +(83.8 g/mol)y=103.75 g
Therefore, we have the next equation:
(1)
4x+83.8y=103.75
2) We can find other equation:
We have 30% helium atoms and 70% Kryptum atoms, therefore we have 30% Helium moles and 70% of Krypton moles.
1 mol is always 6.022 * 10²³ atoms or molecules, (in this case atoms).
Then:
x=number of moles of helium
y=number of moles of helium.
(x+y)=number of moles of our sample.
x=30% of (x+y)
Therefore, we have this other equation:
(2)
x=0.3(x+y)
With the equations(1) and (2), we have the next system of equations:
4x+83.8y=103.75
x=0.3(x+y) ⇒ x=0.3x+0.3y ⇒ x-0.3x=0.3y ⇒ 0.7 x=0.3y ⇒ x=0.3y/0.7
⇒x=3y/7
We solve this system of equations by substitution method.
x=3y/7
4(3y/7)+83.8y=103.75
lower common multiple)7
12y+586.6y=726.25
598.6y=726.25
y=1.21
x=3y/7=3(1.21)/7=0.52
We have 0.52 moles of helium and 1.21 moles of Krypton.
1 mol=6.022 * 10²³ atoms
Total number of particles=(6.022 *10²³ atoms /1 mol) (number of moles of He+ number of moles of Kr).
Total number of particles=6.022 * 10²³ (0.52+1.21)=6.022 * 10²³ (1.73)=
=1.044 * 10²⁴ atoms.
Answer: The sample have 1.044 * 10²⁴ atoms.
Answer:
false, Potassium and fluorine are not halogens.
only fluorine here is halogen.
potassium is an alkali earth metal it doesn't comes under category of halogens, but fluorine
is a non metal which comes under halogen family.
It speeds up chemical reactions
