STAINING, PRACTICAL AND THEORETICAL 



As regards the dye, X = 0-5 ml. and Y = 5 ml. Therefore, to 

 make 100 ml., a quantity of 5 ml. of the 5% safranin is needed. But 

 the final solution has to be in 70% alcohol. 



As regards the alcohol, which has to be diluted from absolute alcohol, 

 X = 70 and Y = 100. 



Therefore 5 ml. of 5% safranin plus 70 ml. of absolute alcohol and 

 25 ml. of water are required to prepare 100 ml. of 0-5% of the dye in 

 70% alcohol. 



3. To prepare 0-03% sodium carbonate from a 10% solution. 

 Here X = 0-03 and Y = 10, so 0-3 ml. of the 10% solution has to 

 be diluted to 100 ml. with water. 



ATOMIC WEIGHTS 



574 



