7. 1 point
The cooling curve below represents the uniform cooling of a substance, starting at a temperature above its boiling point.

During which time interval does the substance exist as both a liquid and a solid?

(1) min 2 to min 4

(2) min 4 to min 5

(3) min 5 to min 7

(4) min 7 to min 9

Liv sheldon given the balanced equation for an organic reaction: c2h2 + 2cl2 → c2h2cl4 this reaction is best classified as *

Answer asap need 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 moles of no2 will form when 3.3 moles of cu are reacted with excess hno3?