Question

un volumen de 2,00 litros de un gas medidos en condiciones normales tiene una masa de 5,7 gramos. Calcular la masa molecular de dicho gas. [ R:64.0 g/mol

Answer 1

aplicar ley de los gases ideales

V x P = n x R x t

V = 2,00  L

P = 1 atm

R = 0.0821 (L atm /molK)

T = 273 K

n = ?

1. . calcular n = ?

n = (2,00 L x 1 atm) / ( 0.0821 (L atm /molK) x 273 K)

n = 0.089 moles

2. calcular Mm de NH3

n = masa / Mm

Mm = masa/n

Mm = 5.7 g / 0.089 mol

Mm = 64.04 g/mol

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   otra manera:

1. calcular moles

1 mol ----- 22.4 L

     x  -----2,00 L

X = 0.089 mol de gas

2. calcular Mm del gas

n = masa / Mm

Mm = masa/n

Mm = 5.7 g / 0.089 mol

Mm = 64.04 g/mol