Question

Afla formula moleculara a substantei cu densitatea fata de aer 2,785, stiind ca 20,125 g substanta formeaza in urma analizei elementale 22g CO2, 11,25g H2O si 35,875 g AgCl

Answer 1

-Calculez masa molara a substantei din densitate si M,aer=29g/mol
d= M,subst/M,aer..........................M sau miu
2,785= M/29---> M=80,76g/mol
- calculez moli substanta, moli CO2, moli H20, moli AgCl
n(niu)= m/M
n= 20,125g/80,76g/mol=0,25mol substanta
n= 22g/44g/mol= 0,5molCO2=0,5molC
n= 11,25g/18g/mol=0,625molH2O-----> n= 1,25molH
n= 35,875g/ 143,5g/mol=0,25mol AgCl = 0,25molCl