Question

Be sure to use proper significant figures for all remaining problems. how many grams of nacl are present in 350 ml of 0.020 m nacl solution? (remember that 1 mole nacl = 58.44 g/mole.)

Answer 1

The answer would be 0.41

Answer 2

Explanation:

Molarity is defined as number of moles of solute present in liter of solution.

Mathematically,        Molarity = $\frac{no. of moles}{volume in liter}$

It is known that 1000 mL equals 1 L so, 350 ml equals 0.35 L. Therefore, calculate no. of moles as follows.

                  Molarity = $\frac{no. of moles}{volume in liter}$

                        0.020 M = $\frac{no. of moles}{0.35 L}$

                 no. of moles = 0.007 mol

Also, it is known that no. of moles equal mass divided by molar mass. Molar mass of NaCl is 58.44 g/mol.

Thus, calculate mass of NaCl as follows.

                        No. of moles = $\frac{mass}{molar mass}$

                        0.007 mol = $\frac{mass}{58.44 g/mol}$

                             mass = 0.409 g

Thus, we can conclude that 0.409 grams of NaCl are present in 350 ml of 0.020 m nacl solution.