Question

How many grams of NaOH are present in 38.0 mL of a 6.20%(m/v) NaOH solution?

Please show all work. Please use sig figs in calculations. Please use units in calculations. :)

Answer 1

Please use sig figs in calculations. Please use units in calculation

Given- mass % = 6.20%

Volume of NaOH = 38.0 ml

6.20% (m/v) NaOH solution means 6.20 g of NaOH is present in 100 ml of NaOH solution

So, in 38 ml of NaOH solution mass of NaOH = 6.2 x (38/100) = 2.356 g

= 2.356 g = (4 sig figs)

Alternate method

Mass % = (mass of solute/volume of solution) x 100

Mass of solute = mass % x volume of solution /100

6.2 x (38/100 ) = 2.356 g

2.356 g of NaOH are present 38 mL solution.