Question

A student was carrying out an investigation for which he wanted to make 0.5M, 200 cm3 solution.
Calculate the mass of (Caustic Soda NaOH), that would be required to make a 0.5M, 200 cm3 solution? [Atomic mass of Sodium: 23.0, Atomic mass of Oxygen: 16.0, Hydrogen=1.0]

Answer 1

Given: The Moles=0.5M,Volume=200cm³ solution and atomic masses of Sodium=23.0,Oxygen=16.0,Hydrogen=1.0

To find:The mass of NaOH required to produce 0.5M,200cm³ solution

Solution:

The atomic mass of NaOH will be 40(∴Atomic mass of Sodium+Atomic mass of Oxygen+Atomic mass of Hydrogen=23.0+16.0+1.0)

The formula to calculate the mass of NaOH is,

N= $\frac{Atomic mass X Moles}{10}$,Mass=$\frac{N X Volume}{100}$

Now substitute the values in the above formula,

N=$\frac{40 X 0.5}{10}$=2

Mass=$\frac{2 X 200}{100}$=4

The mass of NaoH that would be required to make a 0.5M,200cm³ is 4g.