Question

При взаимодействии 30,93 г руды,содержащей карбонат железа(3),с избытком соляной кислоты выделилось 4,48 л углекислого газа.Определить массовую долю карбоната железа в руде?

Answer 1

FECO3+2hcl=Fecl2+Co2+h2o

Vm(co2)=V / Vm=4.48  / 22.4=0.2 моль    (22.4- молярный объём газов при н.у.)

по уравн видно что n(feco3)=n(co2) значит n(Feco3)=0.2 моль

m(Feco3)=n*M=0.2*116=23.2 г

W(Feco3)=m(Feco3) / m(руды)=23.2 / 30.93=0.75- 75% 

Answer 2

Calculation of the Mass Fraction of Iron Carbonate in the Ore

To determine the mass fraction of iron carbonate in the ore, we can use the stoichiometry of the reaction between iron carbonate (FeCO3) and excess hydrochloric acid (HCl). The balanced chemical equation for the reaction is as follows:

FeCO3 + 2HCl -> FeCl2 + H2O + CO2

From the given information, we know that 30.93 g of ore containing iron carbonate reacted with excess hydrochloric acid, resulting in the production of 4.48 L of carbon dioxide gas (CO2).

To calculate the mass fraction of iron carbonate in the ore, we need to find the amount of iron carbonate that reacted. We can use the ideal gas law to convert the volume of carbon dioxide gas to moles:

PV = nRT

Where: P = pressure (assume constant) V = volume of gas (4.48 L) n = number of moles of gas R = ideal gas constant T = temperature (assume constant)

Since the pressure, ideal gas constant, and temperature are assumed to be constant, we can rewrite the equation as:

n = PV / RT

Now, we can calculate the number of moles of carbon dioxide gas produced:

n(CO2) = (4.48 L) / (22.4 L/mol) # Assuming standard temperature and pressure (STP)

Next, we use the stoichiometry of the balanced chemical equation to relate the moles of carbon dioxide gas to the moles of iron carbonate:

1 mol FeCO3 produces 1 mol CO2

Therefore, the number of moles of iron carbonate that reacted is equal to the number of moles of carbon dioxide gas produced.

Now, we can calculate the molar mass of iron carbonate (FeCO3) using the atomic masses of iron (Fe), carbon (C), and oxygen (O):

Molar mass of FeCO3 = (atomic mass of Fe) + (atomic mass of C) + 3 * (atomic mass of O)

Finally, we can calculate the mass fraction of iron carbonate in the ore using the following formula:

Mass fraction of FeCO3 = (mass of FeCO3 / mass of ore) * 100

Let's perform the calculations step by step.

Step 1: Calculate the number of moles of carbon dioxide gas produced

Using the ideal gas law, we can calculate the number of moles of carbon dioxide gas produced:

n(CO2) = (4.48 L) / (22.4 L/mol) # Assuming standard temperature and pressure (STP)

n(CO2) = 0.2 mol

Step 2: Calculate the molar mass of iron carbonate (FeCO3)

The atomic masses of iron (Fe), carbon (C), and oxygen (O) are as follows:

Atomic mass of Fe = 55.845 g/mol Atomic mass of C = 12.011 g/mol Atomic mass of O = 15.999 g/mol

Molar mass of FeCO3 = (55.845 g/mol) + (12.011 g/mol) + 3 * (15.999 g/mol)

Molar mass of FeCO3 = 115.853 g/mol

Step 3: Calculate the mass of iron carbonate (FeCO3)

The mass of iron carbonate (FeCO3) can be calculated using the number of moles of carbon dioxide gas produced and the molar mass of FeCO3:

Mass of FeCO3 = n(CO2) * Molar mass of FeCO3

Mass of FeCO3 = 0.2 mol * 115.853 g/mol

Mass of FeCO3 = 23.171 g

Step 4: Calculate the mass fraction of iron carbonate in the ore

The mass fraction of iron carbonate in the ore can be calculated using the following formula:

Mass fraction of FeCO3 = (mass of FeCO3 / mass of ore) * 100

Given that the mass of the ore is 30.93 g, we can calculate the mass fraction:

Mass fraction of FeCO3 = (23.171 g / 30.93 g) * 100

Mass fraction of FeCO3 ≈ 74.9%

Therefore, the mass fraction of iron carbonate in the ore is approximately 74.9%.

Please note that the calculations provided are based on the given information and assumptions.