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 $\Delta H^o$

The equation used to calculate enthalpy change is of a reaction is:

$\Delta H^o_{rxn}=\sum [n\times \Delta H^o_f(product)]-\sum [n\times \Delta H^o_f(reactant)]$

For the given chemical reaction:

$3CO(g)+2Fe_2O_3(s)\rightarrow Fe(s)+3CO_2(g)$

The equation for the enthalpy change of the above reaction is:

$\Delta H^o_{rxn}=[(1\times \Delta H^o_f_{(Fe(s))})+(3\times \Delta H^o_f_{(CO_2(g))})]-[(3\times \Delta H^o_f_{(CO(g))})+(2\times \Delta H^o_f_{(Fe_2O_3(s))})]$

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 $\Delta H_f$ equal to 0 kJ.

7 0

3 years ago

Which of the following is an example of qualitative

vichka [17]

Answer:

Option =C each mouse in the study has brown ears.

Explanation:

Qualitative:

Qualitative properties are those that can be only observed but not measured in numerical values. These are observed through senses: touch, sight, smell, taste and hear.

For example:

Color, odor, brittleness, taste etc.

Quantitative:

Quantitative properties can be measured in numerical values.

For example:

Melting point, boiling point, conductivity, viscosity, density, hardness and solubility.

In short we can say that qualitative is a measure of quality while the quantitative is a measure of quantity.

4 0

3 years ago

Which arrows represents the phase transitions in which he's energy is gained

ipn [44]

The correct answer would be the first option. The arrows 1, 2 and 3 represent the phase transitions where heat energy is gained. As heat energy is gained the kinetic energy of the molecules in a substance is increased which would cause them to change phases from solid to liquid and to gas.

3 0

4 years ago

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