Group 2 Experiment No. Determining the boiling point and the melting point of a compound helps you to characterize an unknown solid in a quick, easy and cheap way.
Isotopes of lead Natural lead consists of four stable isotopes with mass numbers of,and and traces of five short-lived radioisotopes. This distinction formerly fell to bismuthwith an atomic number of 83, until its only primordial isotopebismuth, was found in to decay very slowly.
Three of the stable isotopes are found in three of the four major decay chains: As uranium decays into lead, their relative amounts change; this is the basis for uranium—lead dating.
Uranium—lead dating and lead—lead dating on this meteorite allowed refinement of the age of the Earth to 4. Apart from the stable isotopes, which make up almost all lead that exists naturally, there are trace quantities of a few radioactive isotopes.
One of them is lead; although it has a half-life of only Lead,and are present in the decay chains of uranium, thorium, and uranium, respectively, so traces of all three of these lead isotopes are found naturally.
Minute traces of lead arise from the very rare cluster decay of radium, one of the daughter products of natural uranium, and the decay chain of neptunium, traces of which are produced by neutron capture in uranium ores. Lead is particularly useful for helping to identify the ages of samples by measuring its ratio to lead both isotopes are present in a single decay chain.
Lead II carbonate is a common constituent;    the sulfate or chloride may also be present in urban or maritime settings. The reaction with chlorine is similar but requires heating, as the resulting chloride layer diminishes the reactivity of the elements.
Compounds of lead Lead shows two main oxidation states: The tetravalent state is common for the carbon group. The divalent state is rare for carbon and siliconminor for germanium, important but not prevailing for tin, and is the more important of the two oxidation states for lead.
The result is a stronger contraction of the lead 6s orbital than is the case for the 6p orbital, making it rather inert in ionic compounds.
The inert pair effect is less applicable to compounds in which lead forms covalent bonds with elements of similar electronegativity, such as carbon in organolead compounds.
In these, the 6s and 6p orbitals remain similarly sized and sp3 hybridization is still energetically favorable. Lead, like carbon, is predominantly tetravalent in such compounds. Even strong oxidizing agents like fluorine and chlorine react with lead to give only PbF2 and PbCl2. As the chloride salt is sparingly soluble in water, in very dilute solutions the precipitation of lead II sulfide is achieved by bubbling hydrogen sulfide through the solution.
Litharge is the most commonly used inorganic compound of lead. Lead sulfide is a semiconductora photoconductorand an extremely sensitive infrared radiation detector.
The other two chalcogenides, lead selenide and lead tellurideare likewise photoconducting. They are unusual in that their color becomes lighter going down the group.
The relative insolubility of the latter forms a useful basis for the gravimetric determination of fluorine. The difluoride was the first solid ionically conducting compound to be discovered inby Michael Faraday.
Lead II nitrate and lead II acetate are very soluble, and this is exploited in the synthesis of other lead compounds.TECHNOLOGY LEVELS A useful concept in science fiction gaming is the technology level (or “tech level”), denoting what a given world .
How does the impurity in water makes its boiling point to increase and freezing point to decrease? Update Cancel. Answer Wiki. 5 Answers.
Elevation in Boiling point: Boiling point is the temperature at which vapour pressure (vp) of the liquid impurities fills the voids btw molecules and hence make it denser and since they possess. Feb 10, · Impurities with a volatility lower than the main component increase the boiling point.
Yeah, that makes more sense. However, is the reason my boiling point is lower than the true value because of an azeotrope?
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Sep 29, · I know that impurities in a solution will cause it to decrease its vapor pressure, have a higher boiling point, and a lower freezing point, but what is . Project Report on Effect of Impurities on the Boiling Point and Freezing Point of A liquid Introduction Project Report Boiling Point and Freezing Point: Generally, on cooling a liquid its temperature falls gradually till it starts freezing.
At this point the temperature remains constant till whole of the liquid changes into solid.