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:
Economic value can be described as a measure of the benefit from a good or service to an economic agent. It is typically measured in units of currency. Another interpretation is that economic value represents the maximum amount of money an agent is willing and able to pay for a good or service.
Explanation:
Answer:THINNER contains more effective for measurin
Explanation:
Something like that wouldn't dissolve in oil
Answer:
e. all of these
Explanation:
Let us check all the given options one by one:
a.The nucleus is positively charged.
Yes it is correct since nucleus contain protons and neutrons and protons are positively charged.
b.The nucleus contains both charged and uncharged particles.
Yes because protons are positively charged and neutrons are neutral in nature.
c.The electrons contribute very little to the total mass of the atom.
Yes we know all the mass of the atom is considered in center and mass of electron is negligible as compared to protons and neutrons.
d.The electrons are located in the atomic space outside the nucleus.
Yes, its a known fact.
e. All of these.
Since , all given options are correct .
Therefore , option e. is right .