Ec - activities
bryanna
bl195552
mastery assess it_5 school year > week 18 > day 87
target due: 1/29/20
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materials
1. a scientist counts 5.62 x 1024 molecules of nacl. how many moles of nacl are in the sample? show your work in
space below.
8.16 moles
11.33 moles
9.33 moles
10.5 moles

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.