Question

Determine the mass of CaBr2 needed to create a 500. ml solution with a concentration of 1.15 M.

Answer 1

Answer:

$m_{CaBr_2}=115gCaBr_2$

Explanation:

Hello,

In this case, we remember molarity is defined as the ratio of the moles of the solute to the volume of the solution in litres, therefore, for the given concentration and volume, we should solve the moles of calcium bromide to subsequently compute the mass, as shown below:

$M=\frac{n}{V}\\ \\n=M*V=1.15\frac{mol}{L} *500mL*\frac{1L}{1000mL}=0.575mol$

Next, since molar mass of calcium bromide is 200 g/mol, we can compute the mass:

$m_{CaBr_2}=0.575mol*\frac{1mol}{200g} \\\\m_{CaBr_2}=115gCaBr_2$

Regards.