Will mark
a substance has a melting point of 80 °c. which of the following is true for the substance? it will also change from a liquid to a solid at 80 °c while the liquid gains energy.

it will also change from a liquid to a gas at 80 °c while the liquid gains energy.

it will also change from a liquid to a gas at 80 °c while the liquid loses energy.

it will also change from a liquid to a solid at 80 °c while the liquid loses energy.

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.