Question

How many grams are need to make 50 ml of a 0.5M NaCl solution? (numbers only, to nearest 0.01)

Answer 1

Answer:

1.46 grams.

Explanations:

Given the following parameters from the question.

Molarity of NaCl = 0.5M

Volume of NaCl = 50ml = 0.05L

Determine the moles of NaCl

$\begin{gathered} moles\text{ of NaCl}=molarity\times volume \\ moles\text{ of NaCl}=\frac{0.5mol}{L}\times0.05L \\ moles\text{ of NaCl=0.025moles} \end{gathered}$

Calculate the mass of NaCl needed

$\begin{gathered} Mass\text{ of NaCl}=moles\times molar\text{ mass} \\ Mass\text{ of NaCl}=0.025moles\times58.44\frac{g}{mol} \\ Mass\text{ of NaCl}\approx1.46grams \end{gathered}$

Hence the number of grams needed to make 50 ml of a 0.5M NaCl solution to the nearest 0.01 is 1.46 grams.