Having problems figurring out my math part of chemistry. Please someone help me.

(Headbang) stressed.

How many moles of NaCl are dissolved in 395 mL of a 1.20M NaCl solution?i am not sure how i am to write this problem out.

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- June 29th 2009, 07:32 AMtroubledmindbasic chemistry formulas
*Having problems figurring out my math part of chemistry. Please someone help me.*

(Headbang) stressed.

**How many moles of NaCl are dissolved in 395 mL of a 1.20M NaCl solution?***i am not sure how i am to write this problem out.* - June 29th 2009, 08:09 AMRaoh
hi(Hi)

In general we have :

here you have and

you do the math(Happy) - June 29th 2009, 08:34 AMalexmahone
mol/litre

litre

Number of moles= =0.474 - June 29th 2009, 08:36 AMtroubledmindomg
you have to be kidding. here i was trying so hard and it was just that easy.

you are the bomb. thank you - June 29th 2009, 08:51 AMtroubledmindi have several questions
how many moles of Al(NO3)3 would be contained in a 15.5 cc sample of a 0.250 M Al(NO3)3 solution> ? ok now will i need to get the atom mass of the element to use in this problem? will i use the mole 6.022 x1023?

how will it write it. i am online chemistr but lab 6 hrs on monday. only see teacher for those 6 hrsx. but busi with lab and no time for problem solving

(Happy) - June 29th 2009, 09:22 AMe^(i*pi)
You can use latex to represent chemical formulae here: . If you have any more chemistry questions there is also CHF (there is a link in my sig)

For this question you do not need to use Avogadro's number because it's asking for a value of moles rather than molecules. You do not need the atomic mass of either since the question asks for the moles and the formula used give you a molar answer.

To solve this you may either use the method outlined in post 2 or you can use the formula:

Where

- is the number of moles
- is the molarity in
- is the volume in

Plugging in the numbers gives: - June 29th 2009, 02:26 PMmr fantastic
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