Question

4. A student was given a sample of MgSO4.7H20 and asked to determine the % water of hydration by a procedure similar to the one which you used. The following data were obtained. Using this data complete the table showing the calculations for the % water in the hydrate. Mass of crucible and hydrate (before heating) 28.45 g 25.40 g Mass of beaker Mass of hydrate Mass of beaker and anhydrous salt (after heating) 27.16 g Mass of water lost from hydrate % water in hydrate (Show calculations below) 4A. Calculate the theoretical % H2O in MgSO4.7H20. (Show calculations below) 4B. Calculate the percent error for the experiment.

Answer 1

Q.4 Mass of crucible and hydrate = 28.45 g Mass of beaker = 25.4og Mass of hydrates 28.45 – 25:40 - 3.054) Mass Os beaker and anhydrous salt = 27.169] Mass of water last from hydrate a 28.45 -27.16 -11-2991 % water in hydrate - mass of water lost from hydrate - 1.29 xico mass of hydrate 3,05^1 = 142.29%) 4(A) Theortical %. Ho in mg SOA 7420 Molar Mass of Mason &H2O = 246.47 olmal Molor mass of 7H2oo7818 = 126 g/mol & Theortical Y. H2O= H20 X 100 Molor mass of 7 H2O Molar McI}} 0+ Mg 30, +H2O huntico 15112% 126 246.47 61.12 - 42:29 x 1co 4B) Purcent error for the experiment 1 l experimental - exact! - x 100 a exact 51.12 - Bills Y100 = 117.27%)