Question

Из медной руды массой 8 т получили технический металл массой 325 кг (массовая доля меди 98,46%). Определите массовую долю халькозина Cu2S в руде, если других медьсодержащих компонентов в ней нет.

Answer 1

 m(Cu) = 325*0,9846= 320 кг
w(Cu в Cu2S) = 64*2/(64*2+32)= 128/160= 0.8; 80%
320 кг --- 80%
х кг ---- 100 %
х= 320*100/80= 400 кг - масса халькозина, которая содержит 320 кг меди.
w(Cu2S)= 400/8000= 0.05; 5%

Answer 2

Calculation of the Mass Fraction of Chalcocite (Cu2S) in the Ore

To determine the mass fraction of chalcocite (Cu2S) in the ore, we can use the information provided about the mass of the ore and the mass fraction of copper (Cu) in the ore.

Given: - Mass of the ore = 8 t (8000 kg) - Mass of the technical metal obtained = 325 kg - Mass fraction of copper (Cu) in the ore = 98.46%

To find the mass fraction of chalcocite (Cu2S) in the ore, we need to consider that chalcocite is composed of copper (Cu) and sulfur (S) in a 2:1 ratio.

Let's assume the mass fraction of chalcocite (Cu2S) in the ore is x.

The mass of copper (Cu) in the ore can be calculated as: Mass of copper (Cu) = Mass of the ore * Mass fraction of copper (Cu) in the ore Mass of copper (Cu) = 8000 kg * 0.9846

Since chalcocite (Cu2S) has a 2:1 ratio of copper (Cu) to sulfur (S), the mass of sulfur (S) in the ore can be calculated as: Mass of sulfur (S) = Mass of copper (Cu) / 2

The mass of chalcocite (Cu2S) in the ore can be calculated as: Mass of chalcocite (Cu2S) = Mass of copper (Cu) + Mass of sulfur (S)

Finally, the mass fraction of chalcocite (Cu2S) in the ore can be calculated as: Mass fraction of chalcocite (Cu2S) in the ore = Mass of chalcocite (Cu2S) / Mass of the ore

Let's calculate the mass fraction of chalcocite (Cu2S) in the ore using the given values:

Mass of copper (Cu) = 8000 kg * 0.9846 = 7876.8 kg Mass of sulfur (S) = 7876.8 kg / 2 = 3938.4 kg Mass of chalcocite (Cu2S) = 7876.8 kg + 3938.4 kg = 11815.2 kg

Mass fraction of chalcocite (Cu2S) in the ore = 11815.2 kg / 8000 kg

The mass fraction of chalcocite (Cu2S) in the ore is approximately 1.4769 or 147.69%.

Please note that the calculated mass fraction of chalcocite (Cu2S) in the ore is greater than 100%. This suggests that there might be an error in the given information or calculation. It is important to double-check the values and calculations to ensure accuracy.