McCrum Prob. 1. 1 Define precision and atomic weights > Digits:=4:H:=1:C:=12: unprotect(0):0:=16:F:=19:c1:=35.5: Calculate relative molar masses(RMM) (1) polybutene >"RMM"=1000*(C+日*2+C+日+(C*2+H*5)); 尺MM=56000 (2)polyvinyl fluoride >RMM=1000*(C+H+2+C+H+F); RMM=46000 (3)polyviny liden chloride >"RMM=1000*(c+H*2+C+c1*2) RMM=97000 (4)polybutyl >·RMNM=1000*(C+H*2+C+(C+日*3)*2); RMM=56000 (5)polyvinyl alcohol >·RMM=1000*(C+H*2+C+H+O+H) RMM=44000 (6) polymethacrylate >RMM"=1000*(C+H*3+C+O+O+C+H+C+H*2); RMM=86000