There is 11 valence electrons in sodium (Na)
Answer: It's colder.
Explanation: Well for starters Valparaiso is further away from the equator, and Australia is already really hot. But say that Valparaiso is further from the equator should be good enough.
1.66 M is the concentration of the chemist's working solution.
<h3>What is molarity?</h3>
Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution. Molarity is also known as the molar concentration of a solution.
In this case, we have a solution of Zn(NO₃)₂.
The chemist wants to prepare a dilute solution of this reactant.
The stock solution of the nitrate has a concentration of 4.93 M, and he wants to prepare 620 mL of a more dilute concentration of the same solution. He adds 210 mL of the stock and completes it with water until it reaches 620 mL.
We want to know the concentration of this diluted solution.
As we are working with the same solution, we can assume that the moles of the stock solution will be conserved in the diluted solution so:
=
(1)
and we also know that:
n = M x 
If we replace this expression in (1) we have:
x
=
x 
Where 1, would be the stock solution and 2, the solution we want to prepare.
So, we already know the concentration and volume used of the stock solution and the desired volume of the diluted one, therefore, all we have to do is replace the given data in (2) and solve for the concentration which is
:
4.93 x 210 = 620 x
= 1.66 M
This is the concentration of the solution prepared.
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Answer:
Molality = <u>10.300 m</u>
<u>Molarity = 6.5970 M</u>
<u>mole fraction = </u>0.156549
Explanation:
39.0 % = ethylene glycol
61.0 % = water
imagine the total mass = 100g
39.0% ethylene glycol = 39g
61.0 % water = 61g
1) Molality = number of moles / mass of solvent (kg)
Molar mass of ethylene glycol = 62.07g/mole
mole = 39g / 62.07g/mole = 0.6283 moles
Molality = moles / mass of solvent = 0.6283 moles / 0.061kg = <u>10.300 m</u>
<u />
<u>2) Molarity</u> = number of moles / volume of solution
Since we know the density of the solution = 1.05g /ml
⇒ volume = 100g / 1.05g /mL = 95.24 mL = 0.09524 L
Molarity = 0.6283 moles / 0.09524 L = <u>6.5970 M</u>
3) Mole fraction
moles water = 61g / 18.02g/mole = 3.38513 moles
Total number of moles = moles of ethylene glycol + moles of water = 0.6283 + 3.38513 = 4.0134276 moles
Mole fraction = 0.6283/ 4.0134276 = 0.156549