# Chemistry

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How many cm3 solution of 36% HCl with density 1.183g/cm3 should be taken to prepare 250cm3 solution with concentration of 0.215 g/dm3.

• Chemistry - ,

First determine the concn of the 36% HCl then use the dilution formula to make whatever concn you need from that.
1.183 g/cc x 1000 cc x 0.36 x (1 mol/36.5g) = ?M HCl for the 36% stuff. You should get approximately 12M
I would convert 0.215 g to mols; 0.215/36.5 = about 0.0059

Then c1v1 = c2v2
12M x v(in cc) = 0.0059 x 250cc
Solve for v.

• Chemistry - ,

DrBob222 can you explain one by one.. i didn't get it

• Chemistry - ,

First you want to determine the molarity of the 36% HCl. M = mols/L.
The density is 1.183 g/cc.
How much does 1000 mL weigh? That's 1.183 x 1000 mL = ?grams = mass 1 L.
How much of that is HCl? 36%. So
? grams x 0.36 = ? g HCl. The rest of it is water.
How many mols HCl is that?
mols HCl = grams HCl/molar mass HCl and molar mass HCl is about 36.5.

Then follow the c1v1 = c2v2 I gave above.

• Chemistry - ,

DrBob222 thanks for answering.Can it be solved this way:

0.250dm3 x 0.215g/dm3 / 1.183g/cm3 x 0.36 = 0.1262 cm3