<u>Answer:</u> For the given equation, only iron has the value of
equal to 0 kJ.
<u>Explanation:</u>
Enthalpy change is defined as the difference in enthalpies of all the product and the reactants each multiplied with their respective number of moles. It is represented as 
The equation used to calculate enthalpy change is of a reaction is:
![\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f(product)]-\sum [n\times \Delta H^o_f(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f%28product%29%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%5Eo_f%28reactant%29%5D)
For the given chemical reaction:

The equation for the enthalpy change of the above reaction is:
![\Delta H^o_{rxn}=[(1\times \Delta H^o_f_{(Fe(s))})+(3\times \Delta H^o_f_{(CO_2(g))})]-[(3\times \Delta H^o_f_{(CO(g))})+(2\times \Delta H^o_f_{(Fe_2O_3(s))})]](https://tex.z-dn.net/?f=%5CDelta%20H%5Eo_%7Brxn%7D%3D%5B%281%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28Fe%28s%29%29%7D%29%2B%283%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28CO_2%28g%29%29%7D%29%5D-%5B%283%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28CO%28g%29%29%7D%29%2B%282%5Ctimes%20%5CDelta%20H%5Eo_f_%7B%28Fe_2O_3%28s%29%29%7D%29%5D)
The enthalpy of formation for the substances present in their elemental state is taken as 0.
Here, iron is present in its elemental state which is solid.
Hence, for the given equation, only iron has the value of
equal to 0 kJ.
Answer:
141 mL is the volume of a 2.30 mol/L solution of Na₂CO₃ that contains 0.325 mol of solute.
Explanation:
Molarity is a measure of concentration of a solution that indicates the amount of moles of solute that appear dissolved in each liter of the mixture.
So 2.30 mol / L indicates that 2.30 moles dissolve in 1 L of solution. You want to know in what volume is contained 0.325 mol of solute. For this you apply the following rule of three: if 2.30 moles of solute are present in 1 L of solution, 0.325 moles in how much volume is it?

volume= 0.141 L
Being 1L=1000 mL, then 0.141 L=141 mL
<u><em>141 mL is the volume of a 2.30 mol/L solution of Na₂CO₃ that contains 0.325 mol of solute.</em></u>
Answer:
260 kPa
Explanation:
To answer this problem we can use <em>Gay-Lussac's law</em>, which states that at a constant volume (such as is the case with a rigid container):
Where in this case:
- T₂ = 273 °C ⇒ 273 + 273.16 = 546 K
We <u>input the data</u>:
- 340 kPa * 546 K = P₂ * 713 K
And <u>solve for P₂</u>:
The pressure of the oxygen gas collected : 718 mmHg
<h3>Further explanation</h3>
Given
P tot = 748 mmHg
P water vapour = 30 mmHg
Required
P Oxygen
Solution
Dalton's law of partial pressures states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases
Can be formulated:
P tot = P1 + P2 + P3 ....
The partial pressure is the pressure of each gas in a mixture
P tot = P H₂O + P Oxygen
P Oxygen = 748 mmHg - 30 mmHg
P Oxygen = 718 mmHg
Most likely the transition metals