Question

Un estudiante debe preparar una disolución 2M de NaCl (58,44 g/mol) en un recipiente de 7L. ?Cuántos gramos de NaCl debe agregar?

Answer 1

Answer:

818.2 g.

Explanation:

• Molarity is the no. of moles of solute per 1.0 L of the solution.

M = (no. of moles of NaCl)/(Volume of the solution (L))

M = 2.0 M.

no. of moles of NaCl = ??? mol,

Volume of the solution = 7.0 L.

∴ (2.0 M) = (no. of moles of NaCl)/(7.0 L)

∴ (no. of moles of NaCl) = (2.0 M)*(7.0 L) = 14.0 mol.

• To find the mass of NaCl, we can use the relation:

no. of moles of NaCl = mass/molar mass

∴ mass of NaCl = (no. of moles of NaCl)*(molar mass) = (14.0 mol)*(58.44 g/mol) = 818.2 g.