182 
IOWA ACADEMY OF SCIENCES 
Action of Bromic Acid on Cadmium. Cadmium slowly dissolves in 
normal bromic acid, no hydrogen being set free. The bromine set free 
corresponded very nearly to the theoretical supposing that two atoms of 
bromine correspond to one of cadmium. 
1. .4507 gram cadmium gave .1240 gram bromine. Calculated .1280. 
2. .2935 grams cadmium gave .0840 grams bromine. Calculated .0835. 
Action of Bromic Acid on Copper. The copper used was in the form 
of line wire of the electrolytic metal. It dissolves readily, and its solu- 
tion takes place readily in the approximately normal acid. 
1. .3706 grams copper gave .1976 grams bromine. Calculated .1864. 
2. .3766 grams copper gave .2020 grams bromine. Calculated .1894. 
Action of Bromic Acid on Tin. Tin is slowly dissolved by bromic 
acid. There remains a very small amount in the form of undissolved 
oxide. The results indicate that the metal goes into the stannic condi- 
tion. 
1. .3365 grams of tin gave .1796 grams bromine. 
2. .3307 grams tin gave .1768 grams bromine. 
The calculated amounts of bromine supposing the tin completely 
oxidized to the stannic condition are .1809 and .1778 grams. 
Some study was made of the action of bromic acid on silver and bis- 
muth. Both are oxidized quite slowly in the cold. Of course the silver 
is soon coated with insoluble silver bromide and bromate. So far as 
investigated the action of bromic acid on silver is quite analogous to 
that of chloric acid; that is, the ratio of the silver as AgBr is to that 
as AgBrO^ as 1 to 5. Of course no bromine is given off in the cases 
of the other metals, the bromic acid being fixed as silver bromide as 
fast as formed. 
The action of bromic acid on metals is about as might have been 
anticipated from the knowledge of the action of chloric acid. Bromic 
acid is a less stable acid and more readily acts as an oxidizing agent. 
The cases are fewer in which it acts upon metals with the liberation of 
hydrogen, and the amounts of hydrogen are smaller in proportion to 
the metal attacked. Its ready reduction by hydrobromic acid, causes 
the latter to be oxidized as fast as formed with the liberation of practi- 
cally the full equivalent of bromine demanded by the equation already 
given. 
