Question

Вычислите массу известняка который надо взять для получения гашеной извести массой 500 килограмм если массовая доля карбоната кальция в известняке составляет 90%

Answer 1

Вся смесь - 500 килограмм. Если массовая доля карбоната кальция - 90%, то массовая доля известняка - 10%
500/100 *10 = 50кг

Answer 2

Calculating the Mass of Limestone

To calculate the mass of limestone needed to obtain 500 kilograms of hydrated lime with a mass fraction of 90% calcium carbonate, we can use the following steps:

1. Determine the Chemical Equation: - The chemical equation for the reaction of limestone (calcium carbonate) to produce hydrated lime (calcium oxide) is: CaCO3(s) → CaO(s) + CO2(g)

2. Calculate the Molar Mass: - The molar mass of calcium carbonate (CaCO3) is approximately 100.09 g/mol.

3. Use the Mass Fraction to Calculate the Mass: - The mass fraction of calcium carbonate in limestone is given as 90%. - This means that in 100 grams of limestone, 90 grams are calcium carbonate.

4. Calculate the Mass of Limestone: - We can use the mass fraction to calculate the mass of limestone needed to obtain 500 kilograms of hydrated lime with a mass fraction of 90% calcium carbonate.

- Let's calculate the mass of limestone required:

- Mass of calcium carbonate in 100 grams of limestone = 90 grams - Mass of calcium carbonate in x grams of limestone = (90/100) * x - Given that the mass of hydrated lime is 500 kilograms (500,000 grams) and the mass fraction of calcium carbonate is 90%, we can set up the following equation: (90/100) * x = 500,000 - Solving for x: x = (500,000 * 100) / 90

- Therefore, the mass of limestone needed to obtain 500 kilograms of hydrated lime with a mass fraction of 90% calcium carbonate is approximately 555,555.56 grams or 555.56 kilograms.

Conclusion

To obtain 500 kilograms of hydrated lime with a mass fraction of 90% calcium carbonate, approximately 555.56 kilograms of limestone should be taken.

I hope this helps! If you have any other questions, feel free to ask.