Which option correctly describes a reactant? 1 substance that is burned and destroyed during a chemical reaction 2 substance that enters into a chemical reaction and is changed by that reaction 3 substance that is present during a chemical reaction but is not affected by that reaction 4 substance that forms as a result of a chemical reaction

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 many atoms or molecules are there in a mole of a substance?

The chemical formula for emerald is be3al2(sio3)6.an emerald can be decided as