C3f-Energy Flashcards
What is an endothermic reaction?
One in which energy is taken from the surroundings
Absorbs energy
What kind of reaction is bond making?
Exothermic
What kind of reaction is bond breaking?
Endothermic process
Describe a calorimetric method for comparing energy transferred per gram of fuel combusted
1) 100cm3 of water
2) put it calorimeter
2) light spirit burner
3) stir water until temperature rises by 20c
4) continue stirring until highest temperature is reached
What is the formula for energy transferred?
M x c x 🔺t
What is m in the energy transferred equation?
Mass of water heated
What is c in energy transferred?
Specific heat capacity
What is 🔺t ?
Temperature change
The formula for energy per gram?
Energy released/ mass of fuel burnt
What is an exothermic reaction?
One in which energy is transferred into the surroundings
Releases energy
Explain why a reaction is exothermic in terms of bond breaking
More energy is given out to make bonds than taken in to break bonds
Explain how a reaction is endothermic in terms of bond breaking
More energy is taken in to break bonds than given out to make bonds
What do you have to measure in the calorimetric method?
1) weigh spirit burner before burning
2) record temperature of water before burning
3) weigh spirit burner after
4) record highest temperature reached
