What is the concentration of o2(g), in parts per million, in a solution that contains 0.008 gram of o2(g) dissolved in 1000. grams of h2o(l)?

concentration of O₂ dissolved in H₂O can be written as ppm

ppm stands for parts per million - mg/kg

the amount of mg in 1 kg of solution

the mass of O₂ - 0.008 g

1000 mg equivalent to 1 g

therefore mass of O₂ in mg - 0.008 g x 1000 mg/g = 8 mg

the mass of water is 1000 g

1000 g is equivalent to 1 kg

mass of water in kg - 1000 g / 1000 g/kg = 1 kg

there's 8 mg of O₂ in 1 kg of water

therefore concentration of O₂ is - 8 mg/kg

also can be written as 8 ppm

answer is 8 ppm

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