Having problems figurring out my math part of chemistry. Please someone help me.
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.
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
You can use latex to represent chemical formulae here: $\displaystyle Al(NO_3)_3$. 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 $\displaystyle Al(NO_3)_3$ 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:
$\displaystyle n = \frac{MV}{1000}$
Where
- $\displaystyle n$ is the number of moles
- $\displaystyle M$ is the molarity in $\displaystyle mol \: dm^{-3}$
- $\displaystyle V$ is the volume in $\displaystyle cm^3$
Plugging in the numbers gives: $\displaystyle n = \frac{0.250 \times 15.5}{1000} = 3.875\times 10^{-3} \text {{ mol }}$
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