Use the bond energies to answer the question.
H–H = 432
H–O = 467
O–O = 146
O=O = 495
H2 (H–H) combines with O2 (O=O) to become hydrogen peroxide (H2O2) bonded as such: H–O–O–H. Which option shows the difference in total bond energy between the reactants and the products?
1,0801
−153
153
−927
Water (H2O) has two O–H bonds. The electronegativity of oxygen is 3.5, whereas hydrogen is 2.1. Which statement best describes the type of bond this molecule has and how the electrons behave?(1 point)
O–H bonds are nonpolar covalent, and oxygen pulls the shared electrons toward it.
O–H bonds are polar covalent, and hydrogen pulls the shared electrons toward it.
O–H bonds are nonpolar covalent, and hydrogen pulls the shared electrons toward it.
O–H bonds are polar covalent, and oxygen pulls the shared electrons toward it.
H2 + O2 ==> H2O2
H-H bond broken = 432
O=O bond broken = 495
Total bonds broken = ?
O-H formed x 2 = 467 x 2 = ?
O-O formed = 146
Total bonds formed = ?
dH = Bond Energy bonds broken - Bond Energy bonds formed = ?
If dH is - it is exothermic; if + it is endothermic
#2 question.
If electronegativity (EN) for O is 3.5 vs H EN is 2.1, that means O has a stroger pull for electrons than H. The difference in EN is 3.5-2.1 = 1.4 which makes it a polar covalent bond. So O-H is a polar covalent bond with the electrons drawn closer to O than H. Looks like d to me.
Post your work if you get stuck.
To calculate the difference in total bond energy between the reactants and the products, we need to find the total bond energy of the reactants and the total bond energy of the products.
Reactants: H2 + O2
Total bond energy of H2 = 2 * H-H = 2 * 432 = 864
Total bond energy of O2 = 1 * O=O = 1 * 495 = 495
Total bond energy of reactants = 864 + 495 = 1359
Product: H2O2
Total bond energy of H2O2 = H-O + O-O + O-H
= 1 * H-O + 1 * O-O + 1 * O-H + 1 * H-O
= 1 * 467 + 1 * 146 + 1 * 467 + 1 * 467
= 1867
Difference in total bond energy = Total bond energy of the products - Total bond energy of the reactants
= 1867 - 1359
= 508
Therefore, the difference in total bond energy between the reactants and the products is 508. The correct option is 508.
To answer the first question, we need to calculate the total bond energy of the reactants (H2 and O2) and compare it to the total bond energy of the product (H2O2).
The reactant, H2, has one H–H bond with a bond energy of 432 kJ/mol. The reactant, O2, has one O=O bond with a bond energy of 495 kJ/mol.
So, the total bond energy of the reactants is:
H2 = 432 kJ/mol
O2 = 495 kJ/mol
Now let's calculate the total bond energy of the product, H2O2. The product, H2O2, has two H–O bonds.
H2O2 = 2(H–O) = 2(467 kJ/mol) = 934 kJ/mol
To find the difference in total bond energy between the reactants and the products, we subtract the total bond energy of the reactants from the total bond energy of the products.
Difference = Total bond energy of products - Total bond energy of reactants
= 934 kJ/mol - (432 kJ/mol + 495 kJ/mol)
= 934 kJ/mol - 927 kJ/mol
= 7 kJ/mol
Therefore, the difference in total bond energy between the reactants and the products is 7 kJ/mol. The correct option is 7.
For the second question, we need to consider the electronegativity difference between oxygen and hydrogen to determine the type of bond and how the electrons behave in the O–H bond in water (H2O).
The electronegativity of oxygen is 3.5, whereas hydrogen is 2.1.
The electronegativity difference between oxygen and hydrogen is 3.5 - 2.1 = 1.4.
A difference in electronegativity greater than 0.4 but less than 1.7 indicates a polar covalent bond.
Since the difference in electronegativity between oxygen and hydrogen is 1.4, the O–H bond in water is a polar covalent bond.
In a polar covalent bond, the shared electrons are pulled more towards the atom with higher electronegativity, which in this case is oxygen.
Therefore, the correct statement is: O–H bonds are polar covalent, and oxygen pulls the shared electrons toward it.