# Does molarity change if you decrease volume?

For example if the solute of the solution contains $$\pu{0.5 mol}$$ and the total volume is $$\pu{0.5 L}$$, the molarity would be $$\pu{1M}$$. But if I take a portion of that solution, let's say $$\pu{0.1 L}$$, would that molarity be still $$\pu{1M}$$? If it were that way, the solute would be $$\pu{0.1 mol}$$ too.

Or, do the moles of the solute stay the same $$\pu{0.5 moles}$$ and the molarity would change to $$\pu{5M}$$?

So my question is, does the solute decrease when the volume decreases too?

• If the concentration of the whole soln is 1M, then a portion taken out remains 1M unless you do something to it. – Waylander Nov 27 '18 at 18:06
• So the solute would be 0,1 moles in 0,1L of the the dissolution, right? Because the concentration would be 1M? – Sirena S. C. Nov 27 '18 at 18:08
• Correct. If you concentrate it down to dry you would expect to get 0.1 moles of the solute – Waylander Nov 27 '18 at 18:22
• Or if I take out a portion of it to mix it with another dissolution, right? – Sirena S. C. Nov 27 '18 at 18:24
• Exactly so. If you take out 50ml to react with something else, that 50ml is at a concentration of 1M – Waylander Nov 27 '18 at 18:25