Energy changes Flashcards
What is exothermic energy?
It is a chemical reaction, where
- heat energy is released to the surroundings
-reactants lose energy
- temp. of surroundings increase
What is Endothermic energy?
It is a chemical reaction where
- heat energy is absorbed from the surroundings
- reactant gain energy
- temp. of surroundings decreases
What are some examples of Exothermic energy?
- burning in oxygen/ combustion
- oxidization
- neutralization (of acid & alkali)
What are some examples of Endothermic energy?
- melting of ice
- photosynthesis
- dissolving ammonium chloride/ potassium nitrate in water
Temperature change for Exothermic energy
+ve, positive!
https://drive.google.com/file/d/1KKVuw-gdmlXfsr4WfU0BPtqU5wTDdj0N/view?usp=drivesdk
Temperature change for Endothermic energy
-ve, negative!
https://drive.google.com/file/d/18RatleK0Km-BhY4R4CwXWw2lyWk7SdxF/view?usp=drivesdk
How does the temperature time graph of a Exothermic energy change look like?
(hint: exothermic >gain energy)
https://drive.google.com/file/d/1RdMsKvTC0IFiLou4DrydxIOddN2acRw0/view?usp=drivesdk
How does the temperature time graph of a Endothermic energy change look like?
(hint: endothermic >lose energy)
https://drive.google.com/file/d/1GPEqoe2BP_TvG0t2KxKOYl64OOIH7Cbu/view?usp=drivesdk
Which of the following is an endothermic reaction?
A) Burning of charcoal
B) Adding sodium hydroxide to sulfuric acid
C) Magnesium reacting in air
D) photosynthesis
Answer: D
A) Burning of charcoal (exothermic>combustion)
B) Adding sodium hydroxide to sulfuric acid ( exothermic> neutralization-acid+alkali)
C) Magnesium reacting in air(exothermic> burning in O2)
D) photosynthesis (endothermic)
Provide an example of an exothermic reaction and explain why it is classified as exothermic.
Combustion reactions, such as the burning of methane (CH4), are examples of exothermic reactions. When methane burns in the presence of oxygen, it produces carbon dioxide (CO2) and water (H2O), releasing a significant amount of heat energy. This is considered exothermic because it results in the release of energy in the form of heat.
