please help!!! 50 POINTS
1) The diagram below models the energy involved in a reaction that changes methane gas and oxygen into carbon dioxide and water.
The graph shows a certain level of energy of reactants C H2 + 2 O2, which increases on the breaking of bonds as the atoms are separated. The energy is then consumed when the making of bonds decreases the energy of products, C O2 + 2 H2 O, to a level much lower than the energy of reactants. The energy change of negative delta H depicts the exothermic reaction.
Which observations about the energy released in making the bonds are correct?
a) It is greater than the energy absorbed in breaking the bonds. The excess is converted to chemical energy.
b) It is greater than the energy absorbed in breaking the bonds. The excess is converted to thermal energy.
c) It is less than the energy absorbed in breaking the bonds. The excess is converted to thermal energy.
d) It is less than the energy absorbed in breaking the bonds. The excess is converted to chemical energy.
2) Carbon dioxide is an example of a molecule where the component atoms of carbon and oxygen are held together by chemical bonds. Which statement correctly describes the reason for these chemical bonds?
a) The nuclei and electrons of the atoms are attracted to each other.
b) The strong nuclear energy bonds the atoms together.
c) The combination of chemical energy stored in each atom makes the bonds strong.
d) The structure of atoms increases their atomic energy, which creates the bonds.
3) When burning fuel for cooking, the pan and the food absorb energy and heat up. In this process, which form of energy is chemical energy converted into?(1 point)
a) thermal energy
b) atomic energy
c) mechanical energy
d) radiant energy
4) Which of the following statement/s about the energy involved in a chemical reaction is/are correct?
I. The energy stored in chemical bonds is kinetic energy.
II. The total energy is conserved during a chemical reaction.
III. Chemical energy can be converted to other forms of energy.
IV. Energy is needed to both break bonds and form new bonds.
a) III and IV only
b) II and III only
c) II, III, and IV only
d) I only
5) Burning coal results in several energy transformations to generate electricity. Which statement is correct about the chemical energy stored in chemical bonds between atoms when coal is burned?
a) It allows the bonds to form and then break.
b) It helps transform kinetic energy to potential energy.
c) It increases the number of atoms.
d) It converts to thermal energy.
thank you!!
