Sea water contains 2% salt (NaCl) by weight. Given that water has a density of 1g/mL. Determine the concentration of salt in:

(a) mg/L , (b) ppm.

a) Concentration of salt in mg/L = 2g/100mL

b) concentration in ppm = 20000 ppm

Explanation:

Percentage composition of salt by weight in water = 2%

Density of water = 1 g/mL

100 mL of water will has a mass of 100 g

Mass of salt in 100 g of water = 2% ×100 g = 2 g

Therefore, 2 g of salt is dissolved in 100 mL of solution

Concentration of salt in 100 mL of solution = 2g/100mL

a) Concentration in mg/L

Mass of salt = 2 g = 2000 mg

Volume of solution = 100 mL = 0.1 L

Concentration in mg/L = 2000 mg/0.1 L

Concentration in mg/L = 20000 mg/L

b) Concentration in ppm

1 ppm = 1mg/L

Therefore, concentration in ppm = 20000 ppm

answer:

the answer is 6 valence electrons.

explanation:

valence is the # of electrons on the outer most shell of an atom.

oxygen has 6.

although, the valency of oxygen is 2, because it only needs to make 2 covalent bonds, or gain 2 electrons, to achieve the stable octet configuration of a noble gas.

that's it!

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~ trueboss72