A) 21.
2 g de NaCl en 135 mL de agua d H2O = 1 g / mLMm NaCl = 58.
45 g / mol1.
Calcular masa de solvente (agua)d = m / vmasa = 1 g / mL x 135 mLmasa = 135 gconvertir g a KgKg = 135 / 1000 = 0.
135 Kg2.
Calcular moles de soluto n = masa / Mmn = 21.
2 g / 58.
45 g / moln = 0.
362 moles de soluto3.
Calcular molalidad m = n / (Kg disolvente)m = 0.
362 mol / 0.
135 Kgm = 2.
68 molal4.
Calcular ΔTe = m x Ke Ke = 0.
52 ºC / mΔTe = 2.
68 m x 0.
52 ºC / mΔTe = 1.
40 ºC5.
Calcular Te = 100 ºC + ΔTeTe = 100 ºC + 1.
40 ºC Te = 101.
40 ºC6.
Calcular Punto de congelación ΔTc = m x Kc Kc = 1.
86 ºC / mΔTc = 2.
68 m x 1.
86 ºC / mΔTc = 4.
98 ºC7.
Calcular Tc = 0ºC - ΔTcTc = 0 ºC - 4.
98 ºCTc = - 4.
98 ºCb.
15. 4 g de urea en 66.
7 mL de agua.
Mm Urea = 60 g / mol1.
Calcular masa de solvente (agua)d = m / vmasa = 1 g / mL x 66.
7 mLmasa = 66.
7 gconvertir g a KgKg = 66.
7 / 1000 = 0.
0667 Kg2.
Calcular moles de soluto n = masa / Mmn = 15.
4 g / 60 g / moln = 0.
256 moles de soluto3.
Calcular molalidad m = n / (Kg disolvente)m = 0.
256 mol / 0.
0667 Kgm = 3.
83 molal4.
Calcular ΔTe = m x Ke Ke = 0.
52 ºC / mΔTe = 3.
83 m x 0.
52 ºC / mΔTe = 1.
99 ºC5.
Calcular Te = 100 ºC + ΔTeTe = 100 ºC + 1.
99 ºC Te = 101.
99 ºC6.
Calcular Punto de congelación ΔTc = m x Kc Kc = 1.
86 ºC / mΔTc = 3.
83 m x 1.
86 ºC / mΔTc = 7.
12 ºC7.
Calcular Tc = 0ºC - ΔTcTc = 0 ºC - 7.
12 ºCTc = - 7.
12 ºC.