Answer:
are there any options for us to choose from? or is it just fill in the blank
OK, so to answer this question, you will simply use the molality equation which is as follows:
<span>M1V1 = M2V2
In the givens you have:
M1 = 2M
V1 is the unknown
M2 = 0.4M
V2 = 100 ml
</span>plug in the givens in the above equation:
<span>2 x V1 = 0.4 x 100
</span>therefore:
V1 = 20 ml
Based on this: you should take 20 ml of the 2 M solution and make volume exactly 100 ml in a volumetric flask by diluting in water.
Answer:
1.635 M
Explanation:
Given:
10 mL of 20 volumes Hydrogen Peroxide
Here,
20 volumes of Hydrogen Peroxide means that on decomposition of 1 mL of H₂O₂ 20 mL of O₂ is obtained
also,
means 1 dm³ of H₂O₂ solution produces 20 dm³ oxygen
Now,
at 298K and 1 atm
20 dm³ oxygen =
moles
or
= 0.817 moles
also,
2H₂O₂ → 2H₂O + O₂
thus,
1 dm³ of solution must contain 2 × moles of O₂ as moles of H₂O₂
thus,
Number of moles of H₂O₂ = 2 × 0.817
or
Number of moles of H₂O₂ = 1.635 moles
Hence,
For 20 volume hydrogen peroxide is 1.635 M