Plant cells use energy from sunlight for photosynthesis. Which row describes and explains the energy change that occurs?
|
| type of energy change | explanation |
| A | endothermic | less energy is released making bonds than is absorbed to break bonds |
| B | endothermic | more energy is released making bonds than is absorbed to break bonds |
| C | exothermic | less energy is released making bonds than is absorbed to break bonds |
| D | exothermic | more energy is released making bonds than is absorbed to break bonds |
1 During an exothermic reaction, heat is given out.
2 The temperature of an endothermic reaction goes up because heat is taken in.
3 Burning methane in the air is an exothermic reaction.
For which reactions would this be an appropriate diagram?
1 CH 4 + 2O 2 → CO 2 + 2H 2 O
2 H 2 + O 2 → 2H 2 O
3 C + O 2 → CO 2
Which statement describes the reaction?
Which type of reaction and energy level diagram apply to the latter reaction?
X 2 (g) + Y 2 (g) → 2XY(g)
The bond energies are shown in the table.
5 g of sodium chloride is dissolved in the water in beaker X. The temperature changes to 18.0 °C.
5 g of calcium oxide is dissolved in the water in beaker Y. The temperature changes to 29.4 °C.
Which types of process are occurring in beakers X and Y?
The equation for the reaction is shown.
N 2 + 3H 2 → 2NH 3
The bond energies are shown in the table.
What is the energy given out during this reaction?
H 2 (g) + Cl 2 (g) → 2HCl (g)
The reaction is exothermic.
The bond energies are shown in the table.
2H 2 O 2 (g) → 2H 2 O(g) + O 2 (g)
The bond energies are shown in the table. The reaction is exothermic.
The bond energies are shown in the table.
What is the energy change for the reaction?
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