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Airida [17]
2 years ago
3

Para regular el contenido de minerales en el agua destinada a la producción de una cerveza se emplean soluciones de cloruro de c

alcio. Si se dispone de una solución de CaCl2 5,00 % m/V, y se desea obtener 4,00 L de una solución 5,00x10-3 M en aniones cloruro, ¿qué volumen de solución concentrada se necesita, expresado en mililitros?
Chemistry
1 answer:
lara31 [8.8K]2 years ago
8 0

Answer:

22.2mL de la solución concentrada se requieren

Explanation:

Lo primero que debemos hacer para solucionar este problema es convertir el 5.00% m/v de CaCl₂ a molaridad de Cl⁻:

5g/100mL = 50g/L

Masa molar CaCl₂: 110.98g/mol.

50g * (1mol / 110.98g) = 0.45 moles CaCl₂/L = 0.45M* 2 = 0.90M Cl⁻ (Se multiplica por dos ya que son dos moles de Cl⁻ por mol de CaCl₂

Ahora, si deseas 4.00L de una solución 5.00x10⁻³M, necesitas:

4.00L * (5.00x10⁻³ moles Cl⁻ / L) = 0.02 moles Cl⁻

Como estas moles vienen de la solución 0.90M:

0.02 moles Cl⁻ * (1L / 0.90 moles) = 0.0222L =

<h3>22.2mL de la solución concentrada se requieren</h3>
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Calculate the cell potential E at 25°C for the reaction 2 Al(s) + 3 Fe2+(aq) → 2 Al3+(aq) + 3 Fe(s) given that [Fe 2+] = 0.020 M
Elodia [21]

Answer:

1.18 V

Explanation:

The given cell is:

Al(s)/Al^{3+}(0.10M)||Fe^{2+}(0.020M)/Fe(s)

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n = number of electrons exchanged = 6

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