A Buna-N sample is made from acrylonitrile (CH2=CH-CN, 53) and buta-1,3-diene (C4H6, 54) and contains 8.70% nitrogen by mass (N 14). The mole ratio of acrylonitrile to butadiene units is

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A Buna-N sample is made from acrylonitrile ( $CH X_{2} = CH - CN$ , 53) and buta-1,3-diene ( $C X_{4} H X_{6}$ , 54) and contains $8.70%$ nitrogen by mass (N 14). The mole ratio of acrylonitrile to butadiene units is

Let the ratio be

x : 1

. N percent

= 14 x / (53 x + 54) \times 100

. For

x = 1/2

7/ (26.5 + 54) = 7/80.5 = 8.70%

. The ratio

1 : 1

would give

13.1%

and

1 : 3

would give

6.5%