Max wants to find out what variables affect the rate at which sugar dissolves in water. He records different information about four containers of water and sugar, as shown in the table below. Which two containers should Max choose to investigate the effects that different temperatures have on the rate at which sugar dissolves?

1 and 2

1 and 3

2 and 3

2 and 4

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o