Question

define a mole of a substancea standard solution of naoh is prepared by dissolving 4 g of the dilute in 250cm3 determine the molarity of the solution​

Answer 1

Answer: The moles of substance present is 0.1 mol and molarity of the solution is 0.4 M.

Step-by-step explanation:

Given: Mass = 4 g

Volume = 250
`cm^(3)` (1
`cm^(3)` = 0.001 L) = 0.250 L

Moles is the mass of a substance divided by its molar mass.

So, moles of NaOH (molar mass = 40 g/mol) is calculated as follows.

`Moles = (mass)/(molar mass)\\= (4 g)/(40 g/ml)\\= 0.1 mol`

Molarity is the number of moles of a substance present in liter of a solution.

Hence, molarity of given NaOH solution is as follows.

`Molarity = (moles)/(Volume (in L))\\= (0.1 mol)/(0.250 L)\\= 0.4 M`

Thus, we can conclude that moles of substance present is 0.1 mol and molarity of the solution is 0.4 M.