Question

Determine a massa molar das seguintes substancias NO2, NH3, PH3, C2H4

Answer 1

massa molar: N---14g/mol P---31g/mol o---16g/mol C----12g/mol H----1g/mol 
logo:
NO2--- 14g/mol+2.16g/mol=44g/mol
PH3----31g/mol+3.1g/mol=34g/mol
NH3----14g/mol+3.1g/mol=17g/mol
C2H4=2.12g/mol+4.1g/mol=28g/mol