Related Questions
In zone refining method, the molten zone :
contains impurities
contains purified metal only
contains more impurity than the original
moves to either side
The Ellingham diagram suggests that the reduction of alumina () by magnesium (Mg) is feasible. Which of the following statements best explains this feasibility?
The Gibbs free energy change for the overall reaction is positive.
The enthalpy change for the reaction is positive.
The entropy change for the reaction is negative.
The Gibbs free energy change for the overall reaction is negative.
Which method of purification is represented by the following equation:
Zone refining
Cupellation
Polling
Van Arkel
In an Ellingham diagram, a line with a more negative slope than another indicates:
A larger increase in entropy during the reaction.
A smaller increase in entropy during the reaction.
A more negative enthalpy change for the reaction.
A less negative enthalpy change for the reaction.
What does a line with a positive slope on an Ellingham diagram represent?
An increase in entropy
A decrease in entropy
An increase in enthalpy
A decrease in enthalpy
In an Ellingham diagram, the slope of the line for the formation of a metal oxide is positive. This indicates that:
The entropy change for the reaction is negative.
The reaction becomes less spontaneous at higher temperatures.
The free energy change becomes more negative at higher temperatures.
The enthalpy change for the reaction is positive.
Which metal, among the following, has the greatest potential to reduce alumina () based on the Ellingham diagram, considering the most negative Gibbs free energy change for the overall reduction process?
Mg
Fe
Zn
Ca
Consider the Ellingham diagram. Which metal oxide among the following can be reduced by coke at a temperature of 1500 K but not at 1200 K?
MgO
Al₂O₃
ZnO
FeO
Which of the following statements is true regarding the Ellingham diagram?
It shows the temperature dependence of the standard Gibbs free energy change for the formation of metal oxides.
It shows the pressure dependence of the standard Gibbs free energy change for the formation of metal oxides.
It shows the concentration dependence of the standard Gibbs free energy change for the formation of metal oxides.
It shows the entropy change for the formation of metal oxides.
For the reaction , the Ellingham diagram shows a negative slope. This is primarily because:
The number of gaseous molecules increases during the reaction.
The reaction is exothermic.
Carbon is a good reducing agent.
Carbon monoxide is a stable gas.
