Lever rule. It is used to determine the percent of liquid and solid phases for a given binary composition and temperature that is between the liquidus and solidus line. In an alloy with two phases, α and β, which themselves contain two elements, A and B, the lever rule states that the weight percentage of the α phase is.
Q. How is the phase diagram of a system defined?
Q. What is the law of the lever?
This is the law of the lever, which was proven by Archimedes using geometric reasoning. It shows that if the distance a from the fulcrum to where the input force is applied (point A) is greater than the distance b from fulcrum to where the output force is applied (point B), then the lever amplifies the input force.
Q. What is the application of lever rule in phase diagram Slideshare?
20. Lever Rule • To determine compositions of phases and the relative proportions of phases to each other in Binary diagrams the LEVER RULE is used. Using the lever rule one can determine quantitatively the relative composition of a mixture in a two-phase region in a phase diagram.
Table of Contents
- Q. How is the phase diagram of a system defined?
- Q. What is the law of the lever?
- Q. What is the application of lever rule in phase diagram Slideshare?
- Q. What is lever rule and its significance?
- Q. How is the lever rule used in chemistry?
- Q. When do you draw a tie line on a phase diagram?
- Q. How is the fraction of a phase determined?
Q. What is lever rule and its significance?
The lever rule is a tool used to determine weight percentages of each phase of a binary equilibrium phase diagram. It is used to determine the percent weight of liquid and solid phases for a given binary composition and temperature that is between the liquidus and solidus.
Archimedes and the Law of the Lever. “Give me a place to stand on, and I will move the earth.”
Q. How is the lever rule used in chemistry?
Phase diagramis a graphical representation of all the equilibriumphases as a function of temperature, pressure, and composition. For one component systems, the equilibrium state of the system is defined by two independent parameters (P and T), (T and V), or (P and V). Phase diagram Pressure-temperature phase diagram for H2O:
Q. When do you draw a tie line on a phase diagram?
Binary phase diagrams. Before any calculations can be made, a tie line is drawn on the phase diagram to determine the percent weight of each element; on the phase diagram to the right it is line segment LS. This tie line is drawn horizontally at the composition’s temperature from one phase to another (here the liquid to the solids).
Q. How is the fraction of a phase determined?
Fraction of a phase is determined by taking the length of the tie line to the phase boundary for the other phase, and dividing by the total length of tie line The lever rule is a mechanical analogy to the mass balance calculation. The tie line in the two-phase region is analogous to a lever balanced on a fulcrum.
