0.50 g of an organic compound was Kjeldahlished. The ammonia evolved was passed in 50 cm^(3) of 1N H_(2)SO_(4). The residual acid required 60 cm^(3) of N // 2 NaOH solution. Calculate the percentage of nitrogen in the compound.

0.50 g of an organic compound was Kjeldahlished. The ammonia evolved w

1.	0.50 g of an organic compound was Kjeldahlished. The ammonia evolved was passed in 50 cm^(3) of 1N H_(2)SO_(4). The residual acid required 60 cm^(3) of N // 2 NaOH solution. Calculate the percentage of nitrogen in the compound.
Answer» Solution :Step 1. CALCULATION of volume of unused acid `"Volume of NaOH solution required" = 60 cm^(3)` `"Normality of NaOH solution" =(1)/(2)N` `"Normality of" H_(2)SO_(4) "solution"= (1)/(N)` Volume of unused acid can be calculated by applying normality equation `underset("Acid")(underbrace(N_(1)V_(1)))=underset("BASE")(underbrace(N_(1)V_(1)))` `1 xx V=(1)/(2) xx 60 = 30 cm^(3)` Step II. Calculation of volume of acid used `"Volume of acid added" = 50 cm^(3)` `"Volume of unused acid" = 30 cm^(3)` `"Volume of acid used"= (50-30) = 20 cm^(3)` Step III. Calculation of percentage of NITROGEN Mass of compound = 0.50 g `"Volume of acid used"=20 cm^(3)` Normality of acid used = 1 N `"Percentage of N" = (1.4 xx "Volume of acid used" xx "Normality of acid used")/("Mass of the compound")` `=(1.4 xx 20 xx 1)/(0.50)=50%`