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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: FeuersternWaCa on March 25, 2022, 05:42:08 AM

Title: I need some advice about what is the right formula to use:
Post by: FeuersternWaCa on March 25, 2022, 05:42:08 AM
I need to find mass concentration (c) and I have M, density (p) and mass fraction w (only in percentage).
The two formula I think I can use are:
$$c=\frac {w*p}M$$
or
$$c=\frac pM$$

Title: Re: I need some advice about what is the right formula to use:
Post by: Borek on March 25, 2022, 06:42:56 AM
Will it help to assume you have exactly 1000 g of the solution? What would the volume be? What would be mass of the solute?
Title: Re: I need some advice about what is the right formula to use:
Post by: FeuersternWaCa on March 25, 2022, 07:32:38 AM
Will it help to assume you have exactly 1000 g of the solution? What would the volume be? What would be mass of the solute?
The only things I have are
$$p=1 \frac {kg}L$$
and
$$M=60 \frac {g}{mol}$$
and
w=0,1%
Title: Re: I need some advice about what is the right formula to use:
Post by: Borek on March 25, 2022, 10:43:33 AM
As I wrote: assume 1000g of solution. What volume does it have? (you know the density, it is a trivial application of the definition)

Finding mass of the solute is also a trivial application of the weight fraction definition.