Please help me ???

Question

Elizabeth wants to precipitate calcium ion in a CaCl₂ solution. She finds that calcium oxalate, CaC₂O₄, is very insoluble in water. Therefore, she decides to add sodium oxalate, Na₂C₂O₄, to precipitate the calcium ion from 45.0 mL of 0.140 M CaCl₂ solution. Show all your calculations for the following questions. 

a) Write a balanced equation for the reaction between CaCl₂ and Na₂C₂O₄.

b) What is the mole ratio between CaCl₂ and Na₂C₂O₄?

c) How many moles of CaCl₂ are in 45.0 mL of 0.140 M CaCl₂ solution?

d) How many moles of Na₂C₂O₄ are required to completely react with 45.0 mL of 0.140 M CaCl₂ solution?

e) What mass of Na₂C₂O₄ is required to precipitate the calcium ion from 45.0 mL of 0.140 M CaCl₂ solution?

Answer 1

a) CaCl₂(aq) + Na₂C₂O₄(aq) ==> CaC₂O₄(s) + 2NaCl(aq)

b) mole ratio is 1 : 1

c) 45.0 ml x 1 L/1000 ml x 0.140 mol/L = 0.00630 moles CaCl₂

d) 0.00630 moles Na₂C₂O₄ are needed because the mole ratio is 1 : 1

e) mass Na₂C₂O₄ = 0.00630 mols x 134 g Na₂C₂O₄/mol = 0.844 g Na₂C₂O₄

Answer 2

Use this video as a guide to answer this question.

https://youtu.be/n7mWr-FLA6Y