What volume of this solution is required to make 1.25 L

[fghtffyrdmns]

Homework Statement

An aqueous stock solution is 85.0% H2SO4 by mass and its density is 1.83 g/mL. What volume of this solution is required to make 1.25 L of 2.75 mol/L H2SO4(aq)? Give your answer in millilitres, accurate to three significant figures.

Homework Equations

$$c1v1=c2v2$$

The Attempt at a Solution

What I did was multiply 0.85 by the density, then to convert to liters, multiplied by 1000. To get the concentration, I just divided by the molar mass of H2SO4 (98.086).

Then I could solve for the volume by using the equation.

 

[Borek]

Sounds reasonable.

Where is the base?

 

[fghtffyrdmns]

Sounds reasonable.

Where is the base?

That's what's confusing me. If I do this, I get the wrong answer.

 

[Borek]

Show numbers, hard to tell what you are doing not seeing details.

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[fghtffyrdmns]

$$(0.85)(1.83 g/mL)(1000 mL/L)(1 mol/98.086 g)$$

This gives you the concentration

Then you can simply find the volume with c1v1=c2v2.

 

[Borek]

That should give you correct molarity of the solution.

You have shown only part of the calculations, so no way anyone can tell you what and where went wrong. If you expect reasonable help, you have to give reasonable amount of information.

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[fghtffyrdmns]

$$v1 = c2v2/c1 v1 = (1.25 L)(2.75 mol/L)/(15.8585 mol/L) = 0.217 L.$$

 

[Borek]

Looks OK to me. The only problem is that density of 85% sulfuric acid is not 1.83 g/mL, but if it was given to you you should use it.

You have earlier wrote that you are getting wrong answer, but I have no idea why do you think so - so I can't help further. Really, if you want to be helped, you need to be more elaborate.

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