Question

g . Calculate the molar concentration for each of the following solutions. (a) 1.50 g NaCl in 100.0 mL of solution (b) 1.50 g K2Cr2O7 in 100.0 mL of solution (c) 5.55 g CaCl2 in 125 mL of solution (d) 5.55 g Na2SO4 in 125 mL of solution

Answer 1

(a)
`M=0.257M`

(b)
`M=0.0510M`

(c)
`M =0.500M`

(d)
`M= 0.391M`

Step-by-step explanation:

Hello,

In this case, since the molarity or molar concentration of a solution is computed by dividing the moles of solute by the volume of solution in liters, we proceed as follows:

(a) The molar mass of sodium chloride is 58.45 g/mol and the volume in liters is 0.100 L, therefore, the molarity is:

`M=(1.50gNaCl)/(0.100L) *(1molNaCl)/(58.45gNaCl) =0.257M`

(b) The molar of potassium dichromate is 294.2 g/mol and the volume in liters is 0.100 L, therefore, the molarity is:

`M=(1.50gK_2Cr_2O_7)/(0.100L) *(1molK_2Cr_2O_7)/(294.2gK_2Cr_2O_7) =0.0510M`

(c) The molar of calcium chloride is 111 g/mol and the volume in liters is 0.125 L, therefore, the molarity is:

`M=(5.55gCaCl_2)/(0.100L) *(1molCaCl_2)/(111gCaCl_2) =0.500M`

(d) The molar of sodium sulfate is 142 g/mol and the volume in liters is 0.125 L, therefore, the molarity is:

`M=(5.55gNa_2SO_4)/(0.100L) *(1molNa_2SO_4)/(142gNa_2SO_4) = 0.391M`

Best regards.