What is the mass percent concentration of a solution containing 29.0 g NaCl and 115.0 mL of water? Assume a density of 1.00 g/mL for water.

Mass percent concentration: 25,2% m/m

Explanation:

The percentage mass by mass indicates the grams of solute in 100 grams of solution. We convert the ml of water into g from the density formula:

δ= m/v    m=δx v= 1 g/ml x 115 ml= 115 g

115g solution29 g NaCl

100g solutionx=(100g solutionx29 g NaCl)/115g solution

x=25,2173913 g NaCl

since electrons are negative the answer is neagtaive

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