`#bot`

1.

`C_2H_6+Cl_2 -> C_2H_5Cl+HCl`

khi đó:

`Delta_r H_(298)^@=E_b (C_2H_6)+E_b (Cl_2)-E_b(C_2H_5Cl)-E_b(HCl)`

`=6E_(b(H-C))+E_(b(C-C))+E_(b(Cl-Cl))-5E_(b(H-C))-E_(b(C-C))-E_(b(C-Cl))-E_(b(H-Cl))`

`=6*413+347+243-5*413-347-339-427`

`=-110(kJ)`

`=>Delta_r H_(298)^@<0=>` p/ứng tỏa nhiệt

2.

`C_3H_6+Cl_2->C_3H_6Cl_2`

khi đó:

`Delta_r H_(298)^@=E_b(C_3H_6)+E_b(Cl_2)-E_b(C_3H_6Cl_2)`

`=6E_(b(H-C))+E_(b(C=C))+E_(b(C-C))+E_(b(Cl-Cl))-2E_(b(C-C))-2E_(b(C-Cl))-6E_(b(H-C))`

`=6*413+614+347+243-2*347-2*339-6*413`

`=-168(kJ)`

`=>Delta_r H_(298)^@<0=>` p/ứng tỏa nhiệt

3.

`C_3H_6O+4O_2->3CO_2+3H_2O`

khi đó:
`Delta_r H_(298)^@=E_b(C_3H_6O)+4E_b(O_2)-3E_b(CO_2)-3E_b(H_2O)`

`=6E_(b(H-C))+E_(b(C=O))+2E_(b(C-C))+4E_(b(O=O))-3*2E_(b(C=O))-3*2E_(b(H-O))`

`=6*413+745+2*347+4*498-6*745-6*467`

`=-1363(kJ)`

`=>Delta_r H_(298)^@<0=>` p/ứng tỏa nhiệt

4.

`C_4H_(10)+13/2 O_2->4CO_2+5H_2O`

khi đó:

`Delta_r H_(298)^@=E_b(C_4H_(10))+13/2 E_b(O_2)-4E_b (CO_2)-5E_b (H_2O)`

`=10E_(b(H-C))+3E_(b(C-C))+13/2E_(b(O=O))-4*2E_(b(C=O))-5*2E_(b(H-O))`

`=10*413+3*347+13/2 *498-8*745-10*467`

`=-2222(kJ)`

`=>Delta_r H_(298)^@<0=>` p/ứng tỏa nhiệt
__________

dựa vào phụ lục ta có ( tất cả đều đơn vị `kJ//m o l` )

`E_(b(H-Cl))=427`

`E_(b(H-C))=413`

`E_(b(O=O))=498`

`E_(b(C-C))=347`

`E_(b(C=C))=614`

`E_(b(C-Cl))=339`

`E_(b(C=O))=745`

`E_(b(Cl-Cl))=243`

tổng quát, có: `Delta_r H_(298)^@=sum E_b (c đ)-sum E_b (s p)`