174 





A, J. Ewavt 



,* 









Water 

 250 



c.c. of 10°; 

 OatrCT.; 



0.0 



,Nu 



z.Q. of 3.57, 

 HO required 



27.7 



Per cent, of f 

 pol^ine 



8 



250 



0.1 





23.9 







20 



250 



0.2 





)S.8 







34 



249.5 



0.5 





17.5 







42 



2i9 



1 .'-> 





14.1 







54 



248 



2.0 





11.6 







62 



247.5 



2.5 





1].2 







62 



246.5 



3.5 





10.1 







66 



245 



5.0 





9.8 







68 



240 



10.0 





9.8 







68 



235 



15.0 





9.8 







68 



230 



20.0 





9.7 







68 



210 



40.0 





9.7 



- 





68 



iformaldehyde, forming calcium formate and polymerising a por- 

 .tion to sugar. No sugar condensation is produced by boiling for- 

 maldehyde with either calcium or^ sodium formates. 



From the equation 2 NaHO + Ca(C00H)2 =CaHij02 + 2 NaCOOH 

 ^0 grams of soda =130 grams of calcium formate .. 10 c.c. of 3.5% 

 NaHO = 5.7 c!c. of 10% calcium formate or 9.8 c.c.% of NaHO = 

 -5.5 c.c. of 10% calcium formate. Hence maximum polymerisa- 

 tion is reached at a point where the soda and calcium formate are 

 approximately equivalent. After that point an excess of calcium 

 formate causes no increase in the percentage polymerisation. 

 When still less calcium formate is present, the amount of soda re- 

 quired rises, more sodium formate being produced and less sugar. 



An addition of 20 c.c. of 10% calcium formate causes an appreci- 

 able rise of the boiling point, and may be responsible for a slight 

 loss of formaldehyde either as vapour or in the form of by-products 

 other than sugar, and not involving any reaction with the calcium 

 hy"drate. Hence the slight decrease in the amount of soda required, 

 which is in fact easily within the limits of error of the method 

 used. In a further series of tests, the percentage of calcium for- 

 mate was kept constant, and the amount of formaldehyde varied, 

 245 c.c. of water and 5 c.c. of 10%^~-6tr€O-^ were used in each experi- 



Tinent. 



C^i^OL )fj^ 



c.c. of 31.. S per cent. 

 CHaO 



1 



4 

 5 



5.5 



6 



7 



c.c. of 3.5 per cent. 

 NallO required 



4.8 





Per cent, of CH .^ 

 polymerized 



20 



6.3 



- 



65 



5.7 



- 



68 



7.9 





67.5 



9.8 



. 



68 



14.3 



- 



56 



18.0 



- 



50 



29.0 



. 



31 



