Question

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

Answer 1

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* volume \\ moles\text{ of NaCl}=(0.5mol)/(L)*0.05L \\ moles\text{ of NaCl=0.025moles} \end{gathered}`

Calculate the mass of NaCl needed

`\begin{gathered} Mass\text{ of NaCl}=moles* molar\text{ mass} \\ Mass\text{ of NaCl}=0.025moles*58.44(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.