Дано:
w(Br2O5)
___________
w(O)-?
____________
Mr(Br2O5)=2×80+5+16=239
Mr(O)=16
w(O)=16÷239+100%=0.06%
Ω(в-ва)= масса вещества/масса раствора х 100%
<span><span><span>3C2H</span><span><span>2 </span><span><span><span><span /><span /></span></span></span><span> </span></span><span>C6H6</span></span></span>
<span><span>X--------------62,4г</span></span>
<span /><span><span>3х26---------78</span></span>
<span><span>Х<span>=62,4</span>г</span></span>
<span /><span><span><span>62,4г----------100</span>%</span></span>
<span /><span><span><span>х-----------------80% х</span><span>=49.92</span>г</span>
</span>
C2H5CI+NaOH--водн. р-р--> CH3CH2-OH+NaCI
M(C2H5CI)=64,5г/моль
n(C2H5CI)=m/M=129/64,5=2моль
n(C2H5CI)=n(C2H5-OH)=2моль
M((C2H5-OH)=46г/моль
m((C2H5-OH))=n*M=2*46=92гр
n(этта)=m(практическая)/m(теоретическую)*100=
85/95*100=89,5%