Calculate AH for the following reaction. C2H4(g) + H2(g) → C2H6(g)
(ΔHf° for C2H4(g) = 52.5 kJ/mol; ΔHf° for C2H6(g) = -84.7 kJ/mol)
a. -137.2 kJ
b. -32.2 kJ
c. 32.2 kJ
d. 137.2 kJ

a.-137.2 kJ

Explanation:

If the first example symbol used is addition you can copy the plus and follow it how to solve the next!And also if the negative or positive sign.

each  column  of the  table  is called a group. elements in a group share similar properties. groups are  read  from  top  to  bottom. metal. metalloid. nonmetal. solid. liquid. gas. fe. hg. o.  2. 3. 4. 5. 6. 7. 8. 9.  2. beryllium. 9.012. 4.  sodium. 22.990.  11. 3.  magnesium. 24.305.  12.  potassium. 39.098.  19. 4.  calcium. 40.078.  20. i guess  i