week 3 Flashcards
what is a ‘pure’ substance
this is a substance that has a fixed chemcial composition throughout
4 examples of a pure substance
water, nitrogen, helium and carbon dioxide
can a pure substancebe made of more than a single elemnt or compound?
yes, it can be made from a mixture of various chemcial elements and compounds
is air a pure substance, even through its mixed with several gases
yes because it has a uniform chemical composition
is a mixutre of water and oil a pure substance
no because they will create 2 seprate regions, and oil isn’t soluble in water
are 2 different forms of substance like air and liquid a pure substance
no because they are no the same type of form
is a mixture of 2 or more phases of a pure substance still a pure substance or not
yes an example is ice and water, also because both phases have the same chemical composition
is liquid, vapour and ice still a pure substance
yes because they still have the same chemical compostion
forms of energy are divided into what 2 groups?
macroscopic and microscopic
what is a macroscopic form of energy
this is the potential and kinetic energy
what is a microscopic form of energy
this is a the sum of all microscopic form of energy called internal energy
what is internal energy
the sum of all microscope form of energy in a system
what is enthalpy
the total heat content of a system
what is a subcooled liquid
a liquid under the boiling point
