題組內容

31. The questions from 31a to 31d share the same conditions. The experiment of determining the chemical formula of magnesium oxide.

31a. The reaction in (a) was carried out in a crucible with a lid and the following data was recorded. Calculate the amount of magnesium, in mol, that was used. [1 mark] 
Mass of crucible and lid = 47.372 ±0.001 g 
Mass of crucible, lid and magnesium ribbon before heating = 53.726 ±0.001 g
 Mass of crucible, lid and product after heating = 56.941 ±0.001 g65fba70775cfb.jpg