Scientists use different types of models to study the composition of matter and how matter behaves. Three different types of molecular models and their uses are shown. Match each type of model with its use.

shows how several water molecules are
oriented in space relative to one another
in addition to showing relative size
and number of atoms in a molecule
arrowBoth
shows the relative size and number of
atoms in a water molecule and how the
atoms are joined to one another
arrowBoth
represents only the type and number
of atoms in a water molecule; used
to represent substances in a
chemical equation
arrowBoth

Answer asap need to be answered by wednesday morning explain how a buffer works, using an ethanoic acid / sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.