Calculate the molarity of a 23.55-ml solution which contains 28.24 mg of sodium sulfate (used in dyeing and printing textiles, = 139.04 g/mol).

The first thing to do is to convert the mass of sodium sulfate to moles. Since the given is in milligrams convert it to grams which would be 0.02824 grams. The number of moles can be calculated by dividing the converted weight with the given molar mass which is 139.04 g/mol. The number of mols in the solution is 2.03x10^-4 mols. Then divide the number of moles with 0.02355 L. The molarity of the solution is 0.00862 M. 

answer: option (4) is the correct answer.

explanation:

areas which are at low altitudes and near the equator tend to receive direct sunlight from the sun. hence, heat energy or radiations from the sun make these areas warmer and they have warmest water.

whereas areas which are at high altitudes and away from the equator do no receive direct sunlight. hence, no direct contact from the sun makes these regions colder and thus, they have colder water.

thus, we can conclude that the statement areas at low latitudes near the equator have the warmest water because they receive the most direct sunlight best explains the relationship between an area's geography and the temperature of its surface water.

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year