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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: sig646 on April 01, 2015, 03:18:34 PM

Title: I cannot solve these pretty easy excersises on molarity...
Post by: sig646 on April 01, 2015, 03:18:34 PM

I have been trying for more than an hour on these 2 problems... Could someone please help me?

The first one:
Calculate the new concentration when 25 ml of 1.2 mole/Litre C2H4O2 is thinned with 30 ml of water.

the second:
In a supply closet stands a bottle with 0.5 litre of NaCl. The concentration is 0.53 mole/litre. You need to have a solution (kitchen salt solution it says which can contain 7 grams/litre. Calculate how much litres solution you can make at the maximum if you utilise the full supply of the bottle.

Title: Re: I cannot solve these pretty easy excersises on molarity...
Post by: thetada on April 01, 2015, 03:24:13 PM

With question 1, does it help if you rephrase it the volume increases from 25 to 55ml?

Title: Re: I cannot solve these pretty easy excersises on molarity...
Post by: sig646 on April 01, 2015, 03:36:38 PM

Not really, sorry, I'm really lost.

Title: Re: I cannot solve these pretty easy excersises on molarity...
Post by: sig646 on April 01, 2015, 03:41:21 PM

Oh wait... I was just able to solve the first one!
So if anyone could just help me with the seconde one, that would be awesome. Thanks.

Title: Re: I cannot solve these pretty easy excersises on molarity...
Post by: Borek on April 01, 2015, 04:07:00 PM

Would it help if you convert 7 g of NaCl per liter to moles per liter?