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1 year ago

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-You wish to make a 0.203 M hydrochloric acid solution from a stock solution of 6.00 M hydrochloric acid. How much concentrated

acid must you add to obtain a total volume of 175 mL of the dilute solution?
mL

-In the laboratory, a student dilutes 20.3 mL of a 8.20 M hydrochloric acid solution to a total volume of 200.0 mL. What is the concentration of the diluted solution?

Concentration =
M
-How many milliliters of 9.36 M perchloric acid solution should be used to prepare 1.50 L of 0.700 M ?

mL

1 answer:

lubasha [3.4K]1 year ago

8 0

For all three questions, we will use the fact that

molarity = (moles of solute)/(liters of solution)

1) For 175 mL of solution at 0.203 M, this means that:

0.203 = (moles of solute)/0.175
moles of solute = 0.035523 mol

Considering the hydrochloric acid solution, if we have 0.035523 mol, then:

6.00 = 0.035523/(liters of solution)
liters of solution = 0.035523/6.00 = 0.0059205 = <u>5.92 mL (to 3 sf)</u>

<u />

2) If there is 20.3 mL = 0.0203 L, then:

8.20 = (moles of solute)/0.0203
moles of solute = 0.16646 mol

This means that the molarity of the diluted solution is:

0.16646/(0.200) = <u>0.832 M (to 3 sf)</u>

<u />

3) If we need 1.50 L of 0.700 M solution, then:

0.700 = (moles of solute)/1.50
moles of solute = 1.05 mol

Considering the 9.36 M acid solution, from which we need 1.05 mol of perchloric acid from,

9.36 = 1.05/(liters of solution)
liters of solution = 1.05/9.36, which is 0.11217948717949 L, or <u>112 mL (to 3 sf)</u>

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Using ideal gas equation :

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V = Volume of gas = ?

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R = Gas constant = 0.0821 L.atm/mol.K

T = Temperature of gas = $14.0^oC=273+14.0=287K$

Putting values in above equation, we get:

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