IOWA ACADEMY OF SCIENCES 
181 
Action of Bromic Acid on Zinc. The zinc was of excellent quality, 
of the same lot described in the paper on chloric acid. Any adherent 
oxide was removed with emery paper. Pure zinc and bromic acid give 
off no hydrogen. The zinc simply goes into solution rapidly and at ordin- 
ary room temperatures. The liberated bromine was aspirated into potas- 
sium iodide solution as described and the free iodine was titrated. 
1. .6010 grams of zinc gave .2792 grams of bromine. Calculated .2979. 
2. .5131 grams zinc gave .2371 grams of bromine. Calculated .2512. 
3. .5808 grams zinc gave .2664 grams bromine. Calculated .2841 
4. .4252 grams zinc gave .2048 grames bromine. Calculated .2093. 
Action of Bromic Acid on Aluminum. Unlike zinc aluminum dis- 
solves in bromic acid with the liberation of considerable quantities of 
hydrogen. It was not deemed practicable to determine the hydrogen and 
the bromine set tree in the same experiment. In one experiment in 
v/hich .2082 gram of aluminum and 23 c. c. of bromic acid of sp. gr. 1.25 
w’ere taken the hydrogen began to come off at the rate of about one bub- 
ble to five seconds, increased to one bubble a second and then gradually 
decreased, practically ceasing after several hours, when 0.1578 gram of 
the metal had dissolved. The hydrogen collected corresponded to .0225 
gram or about 15 per cent of the metal dissolved. 
Two other experiments in which the bromine alone w^as determined 
resulted as follows: 
1. .3113 grams aluminum gave .4632 grams bromine. 
2. .3278 grams aluminum gave .4836 grams bromine. 
If the hydrogen was given off in the same proportion as in the above 
experiment the theoretical amount of bromine corresponding to the 
metal used in reducing the bromic acid are 4753 and 4994. 
Action of Bromic Acid on Magnesium. Bromic acid acts upon mag- 
nesium wuth the rapid evolution of hydrogen at first, but soon free brom- 
ine begins to appear and the hydrogen then slackens as in the case of 
the solution of aluminum. In one experiment .1315 grams 'of magnesium 
wholly dissolved and gave off a volume of hydrogen corresponding to 
37.6 per cent, of the metal. 
Action of Bromic Acid on Iron. Iron rapidly disolved in bromic acid, 
going as might be expected into the ferric condition. Apparently in the 
beginning of the reaction there is a trace of hydrogen set free, but it is 
entirely too small to admit of measurement. 
1. .2469 grams of iron gave .2132 grams of bromine. Calculated .2116. 
2. .2479 grams of iron gave .2088 grams bromine. Calculated .2125. 
Action of Bromic Acid on Sodium. As stated in a former paper 
chloric acid is only very slightly reduced by sodium or potassium amal- 
gam. Bromic acid on the other hand is very readily reduced. In two 
experiments in each of which 5 c. c. of 1.25 normal acid were diluted to • 
20 c. c. and treated with 20 grams , of 2 per . cent amalgam, very little 
hydrogen appeared at first and no bromine. After about an hour the 
hydrobromic acid produced was determined by weighing as silver brom- 
ide. The amounts of bromine in the silver bromide were .1507 and .2196 
grams. 
