Answer to Question #124316 in Organic Chemistry for Mohammed Jebril

Question

When heated, calcium carbonate decomposed part of the substance. At the same time 4.48 liters of gas were released. The mass of the solid residue was 33.2 g. This residue was added to 300 g of hydrochloric acid, taken in excess. Determine the mass fraction of salt in the solution.

Answer 1

WHEN Heated Calcium Carbonate Decomposed gives CaO and CO₂ .

THIS CaO Is Solid Residue And React with 2mol of HCl Gives CaCl₂ (s) and H₂O(l) .

CaCl₂ is as a salt .

moles of CaO = 33.2 /56 . mol ..

left moles of CaO = 0 .

Moles of HCl reacted = 66.4 / 56 .mol ..

left moles of HCl = (300 / 65) - ( 66.4 /56 ) .

Moles of CaCl₂ formed = 33.2 /56 = 0.592 mol..

Moles of H₂O formed = 33.2 /56 mole ..

mass of salt formed =( 0.592 * 111 ) gm = 65.712 gm .

mass of H₂O formed =( 33.2 *18 ) /56 . = 10.671 gm.

mass of HCl formed =( 7.034 * 36.5 ) gm .

Total Mass of solution left after reaction =( 65.712 + 10.67 + 256 .74 ) gm ...... = 333.124 gm ....

Mass fraction of salt in solution = mass of salt / mass of solution =

65.712 / 333.12 = 0.1972 . Answer .