endothermic and exothermic reactions Flashcards
what is enthalpy??
enthalpy is the total chemical potential energy of a chemical system
what is change in enthalpy?
Change in enthalpy is the difference between the enthalpy of the reactants and the products
what is exothermic
heat taken out
what is endothermic
heat taken out
in a chemical reaction where does the energy used used to break bonds come from?
from the kinetic energy of the molecules
when new bonds are formed, what happens to the energy that is being released?
it changes back to kinetic energy that is released
what is a catalyst
a substance that promotes which promotes a chemical reaction without undergoing any permanent change
what is the effect of using a catalyst in a reaction?
increases the rate of a chemical reaction but it is not used up (remains chemically unchanged at the end). … It provides an alternative reaction pathway of lower activation energy.
how does the energy of a single bond between 2 atoms compare with that of a double bond between the same 2 atoms?
the bond energy of a double bond is higher than that of a single bond
draw an energy diagram of an endothermic reaction
see page 209
draw an energy diagram of an exothermic reaction
see page 209
what is combustion?
a chemical reaction between substances, usually including oxygen and usually accompanied by the generation of heat and light in the form of flame.
what is respiration??
Respiration is the chemical process by which organic compounds release energy. The compounds change into different ones by exergonic reactions.
what is photosynthesis??
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism’s activities
what is the formula for change in energy?
energy taken in -energy taken out
