A student has a petri dish and several marbles. Which of the following activities should the student perform to demonstrate phase transition from a liquid to solid? (1 point)
-Placing a few marbles in the petri dish and shaking them vigorously to represent removal of energy
-Packing the petri dish with two layers of marbles and slowly jiggling them to represent removal of energy
-Packing the petri dish with two layers of marbles and slowly jiggling them to represent addition of energy -Placing a few in the petri dish and shaking them vigorously to represent addition of energy

How many grams of aluminum will there be in 98g of al2o3?

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.

How do you determine the percent yield of a chemical reaction