H2(g) +C2H4(g)→C2H6(g)
H-H +H2C =CH2→H3C-Ch3
2C -H bonds and one C-C bond are formed while enthalpy change (dH) of the reaction,
H-H: 432kJ/mol
C=C: 614kJ/mol
C-C: 413 kJ/mol
C-C: 347 kJ/mol
dH is equal to sum of the energies released during the formation of new bonds or negative sign, and sum of energies required to break old bonds or positive sign.
The bond which breaks energy is positive.
432+614 =1046kJ/mol
Formation of bond energy is negative
2(413) + 347 = 1173 kJ/mol
dH reaction is -1173 + 1046 =-127kJ/mol
Answer:
The periodic table has gone through many changes since Dmitri Mendeleev drew up its original design in 1869, yet both the first table and the modern periodic table are important for the same reason: The periodic table organizes elements according to similar properties so you can tell the characteristics of an element just by looking at its location on the table
Explanation:
hope it helps you
Answer:
Nitrogen
Explanation:
Elements in period two includes lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine and neon.
According to periodic trends, the electro negativity values are expected to increase across the period up to fluorine. Hence, as we go right wards, we encounter elements with higher electronegative values.
While lithium has an electronegative value of 1 , the electronegative value of element nitrogen is thrrr times this which is equal to three
The crust
1. divergent (moves away from each other)
2. convergent (moves towards each other)
3. transform (slides past each other)
Answer:
At the top of Group 11 above silver and gold.
Period 4
Explanation: