120grams. Option B is correct
The formula for calculating the molarity of a solution is expressed as:
[tex]molarity=\frac{mole}{volume}[/tex]Given the following parameters
• Volume of solution = 1.5L
,• Molarity = 0.50M
Determine the moles of calcium nitrate
[tex]\begin{gathered} moles=molarity\times volume \\ moles=0.5M\times1.5L \\ moles=0.75moles \end{gathered}[/tex]Determine the mass of calcium nitrate
[tex]\begin{gathered} mass=mole\times molar\text{ mass} \\ mass=0.75\cancel{moles}\times\frac{164.088g}{\cancel{mol}} \\ mass\text{ of Ca\lparen NO}_3\text{\rparen}_2=123grams \\ mass\text{ of Ca\lparen NO}_3\text{\rparen}_2\approx120grams \end{gathered}[/tex]Hence the amount of calcium nitrate needed in correct significant figures is 120grams
