The volume of the stock solution needed is 213.88 mL to get new concentration.
<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.
Determination of the volume of stock solution.
Volume of diluted solution (V₂) =550 mL
Molarity of diluted solution (M₂) =0.70 M
Molarity of stock solution (M₁) = 1.8 M
Volume of stock solution needed (V₁) =?
M₁V₁ = M₂V₂
1.8 M × V₁ = 0.70 M × 550 mL
V₁ = 213.88 mL
Thus, the volume of the stock solution needed is 213.88 mL.
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The periodic law is a law relating the properties of the element with their
atomic numbers.
The element is <u>potassium, K</u>.
Reason:
By atomic mass, potassium is 39.10 g, while argon is 39.10 g.
Going by the atomic mass alone, potassium should come before argon in
the periodic table and therefore should be an halogen and not an alkali
metal.
However, the number of protons in the potassium is 19, and therefore larger
than the number of protons in argon, which is argon.
Therefore, the element is <u>potassium, K</u>.
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a) chemical energy
b) by electricity
c)
(i) Light
(ii) thermal transfer
<em>By </em><em>Benjemin</em>
The given question is incorrect. The correct question is as follows.
If 20.0 g of 
and 4.4 g of 
are placed in a 5.00 L container at 
, what is the pressure of this mixture of gases?
Explanation:
As we know that number of moles equal to the mass of substance divided by its molar mass.
Mathematically, No. of moles = 
Hence, we will calculate the moles of oxygen as follows.
No. of moles =
Moles of = 
= 0.625 moles
Now, moles of 
= 0.1 moles
Therefore, total number of moles present are as follows.
Total moles = moles of + moles of
= 0.625 + 0.1
= 0.725 moles
And, total temperature will be:
T = (21 + 273) K = 294 K
According to ideal gas equation,
PV = nRT
Now, putting the given values into the above formula as follows.
P = 
= 
= 
atm
= 3.498 atm
or, = 3.50 atm (approx)
Therefore, we can conclude that the pressure of this mixture of gases is 3.50 atm.
C is the correct answer because density is mass per unit volume and when you divide it we that volume is greater than mass so density is less density density is directly proportional to Mass Density is inversely proportional to volume
