Question

lets say a colleague working in the lab needs to create a solution containing 7.99e+1 grams of nacl. if she has a 3.0 m stock solution of nacl dissolved in water, how many liters of the stock solution would she need to have 7.99e+1 grams nacl? liters

Explanation:

Step1: Calculate the number of moles of NaCl

The molar mass of \(NaCl\) is \(M = 58.44\space g/mol\).
The mass of \(NaCl\), \(m=7.99\times10^{1}\space g\).
Using the formula \(n=\frac{m}{M}\), we have \(n=\frac{79.9\space g}{58.44\space g/mol}\approx1.37\space mol\).

Step2: Calculate the volume of the stock solution

The molarity formula is \(M=\frac{n}{V}\), where \(M = 3.0\space M\) and \(n = 1.37\space mol\).
Rearranging for \(V\), we get \(V=\frac{n}{M}\).
Substituting the values, \(V=\frac{1.37\space mol}{3.0\space mol/L}\approx0.46\space L\).

Answer:

\(0.46\)