Chapter-3-Chemistry-of-Nonmetals-1-1.docx - Chapter 3:...

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Chapter 3:Chemistry of NonmetalsNONMETALSObjectives:At the end of the module you should be able to:Discuss the occurrence, preparation and uses on nonmetals.Appreciate the importance of nonmetalsHYDROGENOccurrence of Hydrogen:occurs chiefly combined with oxygen, commonly known as water and with carbonas hydrocarbonsfound in volcanic gases and in natural gas, wood, coal and oilElemental hydrogen is very rare in our planet’s atmosphere, but it is the mostabundant of all elements in the universe as a whole (i.e., hydrogen comprises 75 %of the mass of the sun).Ranks ninth in abundance by mass among the chemical elements in the earth’ssurface environment.found in all acidsHydrogen is in nearly every compound in the human body. For example, it is inkeratin, the main protein that forms our hair and skin, and in the enzymes thatdigest food in our intestines.Hydrogen is in DNA, the molecules that code our genetic information and makeeach species of plant or animal unique (and every person unique).Hydrogen is in the molecules in food that provide energy: fats, proteins, andcarbohydrates.Preparation of Hydrogen:1.From acids by replacement.All acids contain hydrogen, which may be displaced by reaction with metals thatare above hydrogen in the activity series.Zn+2HCl2ZnCl2+H22.From water by replacement.2Na+2H2O2NaOH+H23.From water by electrolysis.During the electrolysis of water, a direct current is passed through waterOxygen gas is collected at the positive terminal (anode) and hydrogen gas thenegative terminal (cathode).Sulfuric acid is added to make the water a better conductor of electricity.4.From hydrocarbons.Hydrocarbons – compounds of hydrogen and carbonHydrocarbon reacts with steam in the presence of a nickel catalyst at atemperature of about 850 ºC.CH4+H2OCO(g)+3H2 (g)24
Chapter 3:Chemistry of Nonmetals5.From water by hot carbon.When steam is passed over red hot coal or coke, a mixture of gases called watergas*is formed.*consists mainly of hydrogen and carbon monoxideC+H2OCO(g)+H2 (g)Uses of Hydrogen:1.For the production of ammonia (NH3).Ammonia is used to produce ammoniumnitrate, a fertilizer2.In petroleum refining.*Hydrogen is used in refining thick sulfur-containing crude oil thus improving theoil’s quality as a fuel.3.For solidifying oils.*Some of the molecules in the liquid oil combine with hydrogen atoms to producea substance that issolid at room temperature but still a liquid at bodytemperature.4.As a reducing agent.*Hydrogen could be used as a reducing agent to separate the metals from theiroxide ores.5.As a fuel.*Nearly all fuels contain hydrogen, either free or combined with other elements.*Hydrogen is used as a fuel for the oxyhydrogen torch.

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Term
Spring
Professor
McFinster
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