1132 
Sunlight Diffused light Darkness 
3'— 40" 5'—-45" 18 
= 
Then 5 c.c. Vi LMnO, added in each of the bottles; colour dis- 
appears after 
2! 5'—20" 11'—30" 
N NE 
2) Hee. = citrie acid and 5 ee. a KMnO, ; colour disappears 
) 
after 
2585 Lbb 12'—45". 
D. Permanganate and Malie acid. 
N Na ; 
1) 10 cc. — Malie acid and 10 ec. 0 KMnO,; colour disappears 
) 
after 
Sunlight Diffused light Darkness 
6'—10" 10'—15" 28' 
iN é Ni ; : 
2) 10 ec. — malic acid and 3 c.c. Th KMnO,; colour disappears after 
o 
Sunlight Diffused light Darkness 
3—5" 5'—10" 9'—20". 
E. Permanganate and lactic acid. 
N N 
df 3 
1) 10 ee. > lactic acid and 7.5 cc. 0 KMnO,; colour disappears 
after 
8'—40' 25'— 13" 54! 
N N 
2) 10 ee. > lactic acid and 1S ce.c ioe MnO,; colour disappears 
after 
10'—10" 30'—15" Gil: 
F. _Permanganate and Malonic acid. 
N es 4 : 
1) 20c.c. — Malonie acid and 5 ce. — ‚; colour disappears 
— KMnO 
0 
5 1 
after 
Sunlight Diffused light Darkness 
20' 30'—40" 40'—10". 
N N € 
2) 25 e.e. — Malonic acid and 2.5 c.c. Ti KMnO,; colour dis- 
0 
appears after 
15'—20" 25'— 20" 38'—20". 
It is well known that manganese ions (Mn°°) act as a positive 
catalyst in the oxidation of oxalic acid by permanganate. 
