High School

A solution (100 mL) that contains 409.5 mg of NaCl/100 mL has how many mEq of Na and Cl-? [It's the same number.] The molecular weight of NaCl is 58.5.

Answer :

The number of meq of Na and Cl is 0.007.

We know that 1 milliequivalent (meq) of a substance is the amount of substance equal to its molecular weight divided by the valency.

Now, Number of moles of NaCl = Mass of NaCl/Molecular weight of NaCl

Mass of NaCl = 409.5 mg = 0.4095 g .

Number of moles of NaCl = 0.4095/58.5 = 0.007 mol .

Number of meq of Na+ = Number of moles of Na+ x Valency,

Valency of Na+ = 1 (since Na+ has a valency of 1)

Number of meq of Na+ = 0.007 x 1 = 0.007 meq.

Number of meq of Cl- = Number of moles of Cl- x Valency ,

Valency of Cl- = 1 (since Cl- has a valency of 1 )

Number of meq of Cl- = 0.007 x 1 = 0.007 meq.

Therefore, the number of meq of na and cl is 0.007.

To know more about meq visit:

https://brainly.com/question/27753964

#SPJ11

Final answer:

To determine the milliequivalents of Na+ and Cl- in the solution, convert the mass of NaCl to moles using its molar mass, and then multiply by 1000 to convert from moles to meq. Therefore, The solution contains 7 meq each of Na+ and Cl-.

Explanation:

To find the meq of Na+ and Cl-, first we need to know the molar mass of NaCl, which is 58.5 g/mol.

Since there are 1000 mg in 1 g, 409.5 mg of NaCl is equivalent to 0.4095 g.

We then convert grams to moles by dividing by the molar mass: 0.4095 g ÷ 58.5 g/mol = 0.007 moles of NaCl.

Since NaCl dissociates into equal numbers of Na+ and Cl-, we have 0.007 moles of each ion.

To convert moles to milliequivalents, we use the fact that 1 eq of Na or Cl is the same as 1 mole, and thus 1 meq is 1/1000th of a mole.

Therefore, we have: 0.007 moles × 1000 meq/mole = 7 meq of Na+ and likewise, 7 meq of Cl-.