Answer to Question #175844 in General Chemistry for Emmanuel

Question

Ada was required to standardize a solution of HCL using o.125 mol dm-3 Na2CO3 solution.

Ada titrated the acid against 20.0cm3 portions of the Na2CO3 solution using Phenolphthalein indicator, and got the titre value 25.45cm3,

Using this titre value of 25.45cm3,

1. Write a balanced equation for the solution

2. determine the concentration of the HCL in mol dm-3.

3. Calculate the mass of anhydrous Na2CO3 required to prepared 250cm3 of 0.125mol dm-3 Na2CO3 solution.

Bonus tip: (C=12.0, O = 16.0, Na = 23.0).

 

Answer 1

1)Na2CO3 + 2 HCl → 2 NaCl + H2CO3

 2) number of moles HCl= 25.45/36.5= 0.697moles

Therefore 0.0697mol are in 1dm3

3)C=12.0, O = 16.0, Na = 23.0).