236 C. W. R. POWELL. 
The effect of manganese sulphate as indicated by these 
experiments is to considerably increase the initial velocity 
of reaction. A comparison was made between the figures 
by tabulating the times taken to decompose definite frac- 
tions for tbe various concentrations of manganese sulphate. 
Table F. 
Concentration of Time taken to proceed (at 15° C.) 
MnSO,. One-eighth. One-sixth. Half-way. 
0000 31 37 63 
0008 N. 7 20 45 
0040 ,, (3) (4) 12 
The velocity of reaction, however, still increases as the 
reaction proceeds, although not to the same extent as when 
no manganese sulphate is present. A more complete series 
of experiments was made with solutions having an acid 
concentration of °58N. in which the addition of manganese > 
sulphate was continued until no further accelerative effect 
was obtained. 
16. Temperature 15° C. Sulphuric acid ‘58 N. Manganese 
sulphate ‘0008 N. 
t n 2 (a-x) (b-«x) k, k, 
ep 6:3 am 073) “Ol s BA we 
5 6:5 "0001 0730 «© 0112 = °0018 -0000025 
15, 2 10-2 ‘0031 ‘0700 -0082 -0208 0000238 
bea 2 0038 -0693 -0075 , -0229. ‘0000sz0 
22: 126 70049 -0682 -0064 ~<°0253 )-00005GT% 
Did. ib Aey 70066 »=-0665 = 0047) — -0320 = -0000468 
3 ee ba 0099s -0632=—_ -0014 «= 0522 »=— -0000766 
e JOO ‘Hii. “0618 
17. Temperature 15° C. Sulphuric Bab ‘58 N. Manganese 
sulphate ‘004 N. 
t n x (a—x) (b-2x) k, ke 
1 5:3 ne ‘0731 4g pOlis “> iu 
l H235 4. 20001 0730 =6:0112 »=-0090 -0000123 
3 6:2 0007 = 0724 «= 0106 ~=— 0210 §=-0000293 
6 9-0 0028 0703 -0085 0471 -0000662 
8 10°4 0036 0693 -0075 -0518 0000720 
£2) oe9 0058 -0673 -0055 -0588  -0000858 
LG my dG-2 0074 :0657 :0039 -0676 -0000967 
20 Aged 0090s 0641 »=—:0033)- 0772 = :000118 
oc 20°3 ‘OMS .-Dols 
