The Student Room Group

Determination of formula, experimental procedure question and mass spectrometer

A porcelain boat was weighed. After a sample of the oxide of a metal M, of Ar =119, was placed in the boat, the boat was reweighed. Then the boat was placed in a reduction tube, and heated while a steam of hydrogen was passed over it. The oxide was reduced to the metal M. The boat was allowed to cool with hydrogen still passing over it, and then reweighed. Then it was reheated in hydrogen, cooled again and reweighed. The following results were obtained.

Mass of boat = 6.10 g
Mass of boat + metal oxide = 10.63 g
Mass of boat + metal (1) = 9.67 g
Mass of boat + metal (2) = 9.67 g

1. Explain why hydrogen was passed over the boat while it was cooling.
2. Explain why the boat + metal was reheated.

Also would it be possible to calculate the ratio of the peaks in the mass spectrum for chlorine supposing I was told the RAM was 35.45 and peaks occurred at 35, 37, 70, 72 and 74.
supreme


1. Explain why hydrogen was passed over the boat while it was cooling.


So that the metal did not reoxidise.


2. Explain why the boat + metal was reheated.



To ensure oxidation was complete and that no further mass loss occured.