A crayon melting in the sun is it chemical or physical change

How much would the freezing point of water decrease if 4 mol of sugar were added to 1 kg of water(k=1.86 c/mol/kg for water and i=1 for sugar

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.

Plz ill give u brainliest which of the following steps is not likely to take place during cellular respiration? a.oxygen combines with carbon of simple sugar. b. energy molecule transfers energy to cells. d. energy is used up.