The formula for finding the molarity of a solute is #"Molarity" = frac("moles of solute")("volume of solution")#.
We are already provided with the molarity, but we still need to find the number of moles of solute:
#Rightarrow n = frac(m)(M)#
#Rightarrow n = frac(6.94 " g")((40.08 + 2 times 35.45) " g mol"^(- 1))#
#Rightarrow n = frac(6.94)(110.98 " mol"^(- 1))#
#Rightarrow n = 0.0625# #"mol"#
Then, let's substitute all relevant values into the formula for molarity:
#Rightarrow 0.250 "M" = frac(0.0625 " mol")("volume of solution")#
#Rightarrow 0.250 "mol L"^(- 1) = frac(0.0625 " mol")("volume of solution")#
#Rightarrow "Volume of solution" = frac(0.0625 " mol")(0.250 " mol L"^(- 1))#
#Rightarrow "Volume of solution" = 0.250# #"L"#
#therefore "Volume of solution" = 250# #"mL"#
Therefore, the volume of the calcium chloride solution is #250# #"mL"#.
