Question

How many moles of NaCl are contained in each solution?

1.7 L of a 1.4 M NaCl solution

Express your answer using two significant figures.

0.478 L of a 0.95 M NaCl solution

Express your answer using two significant figures.

149 mL of a 1.95 M NaCl solution

Express your answer using three significant figures.

Answer 1

1)   no of mol of NaCl = M*v

                  = 1.4*1.7 = 2.38 mol

no of molecules of NaCl = n*Na

                        = 2.38*6.023*10^23

                        = 1.43*10^24 molecules

2) no of mol of NaCl = M*v

                  = 0.95*0.478 = 0.4541 mol

no of molecules of NaCl = n*Na

                        = 0.4541*6.023*10^23

                        = 2.73*10^24 molecules

3) no of mol of NaCl = M*v

                  = 0.149*1.95 = 0.29 mol

no of molecules of NaCl = n*Na

                        = 0.29*6.023*10^23

                        = 1.75*10^24 molecules