Question

При полном востоновлении 48 г оксида железа (lll) избытком алюминия выделилось 256,2 кДж теплоты . определите тепловой эффект реакции Fe2O3 + 2AI =2Fe + 2AI2O3

Answer 1

 48                                         256,2кДж
Fe2O3 + 2AI =2Fe +2AI2O3+Q
56*2+16*3                             х
160

48--------------256,2
160-------------х
х=256,2*160/48=854 кДж

Answer 2

Calculation of the Heat Effect of the Reaction Fe2O3 + 2Al = 2Fe + 2Al2O3

To determine the heat effect of the reaction Fe2O3 + 2Al = 2Fe + 2Al2O3, we need to calculate the heat released or absorbed during the reaction. This can be done using the concept of enthalpy change, which is the difference in enthalpy between the products and reactants.

The balanced equation for the reaction is: Fe2O3 + 2Al = 2Fe + 2Al2O3

To calculate the heat effect, we need to know the enthalpy change for each substance involved in the reaction. The enthalpy change for a reaction is typically given in units of kilojoules per mole (kJ/mol).

According to the information provided, when 48 g of iron(III) oxide (Fe2O3) is completely restored with an excess of aluminum (Al), 256.2 kJ of heat is released.

To calculate the heat effect of the reaction, we can use the following steps:

1. Convert the mass of Fe2O3 to moles using its molar mass. 2. Use the stoichiometry of the balanced equation to determine the moles of Al consumed and the moles of Fe and Al2O3 produced. 3. Calculate the heat effect using the enthalpy change per mole of reaction.

Let's perform the calculations:

1. Convert the mass of Fe2O3 to moles: - Molar mass of Fe2O3 = 2 * atomic mass of Fe + 3 * atomic mass of O - Molar mass of Fe2O3 = (2 * 55.845 g/mol) + (3 * 16.00 g/mol) = 159.69 g/mol - Moles of Fe2O3 = mass of Fe2O3 / molar mass of Fe2O3 - Moles of Fe2O3 = 48 g / 159.69 g/mol = 0.3008 mol

2. Use the stoichiometry of the balanced equation: - From the balanced equation, we can see that 2 moles of Al react with 1 mole of Fe2O3 to produce 2 moles of Fe and 2 moles of Al2O3. - Moles of Al consumed = 2 * moles of Fe2O3 = 2 * 0.3008 mol = 0.6016 mol - Moles of Fe produced = 2 * moles of Fe2O3 = 2 * 0.3008 mol = 0.6016 mol - Moles of Al2O3 produced = 2 * moles of Fe2O3 = 2 * 0.3008 mol = 0.6016 mol

3. Calculate the heat effect: - The heat effect is given as 256.2 kJ for the reaction of 0.3008 mol of Fe2O3. - Heat effect per mole of reaction = 256.2 kJ / 0.3008 mol = 850.9 kJ/mol

Therefore, the heat effect of the reaction Fe2O3 + 2Al = 2Fe + 2Al2O3 is 850.9 kJ/mol.

Please note that the calculation assumes that the reaction is carried out under standard conditions and that the heat effect is constant regardless of the amount of reactants used.