22 -- Part 7: Chemistry of the Main Group Elements II:
As we contemplate the decline of fossil fuels, hydrogen becomes an attractive means of storing, transporting, and using energy.
When an automobile engine burns hydrogen instead of gasoline, its exhaust is pollution free.
The range of supersonic aircraft could be increased if they used liquid hydrogen as a fuel.
The space plane might become possible.
One method of using hydrogen that is already available combines H2 and O2 to form H2O in an electrochemical fuel cell, which converts Chemi cal energy directly to electricity.
The conversion of electrical energy to mechanical energy can be done more efficiently than the conversion of heat to mechanical energy.
Finding a cheap source of hydrogen is one of the basic problems.
It is possible to use hydrogen made by the electrolysis of seawater.
If nuclear fusion energy can be developed, this possibility requires an abundant energy source.
The thermal decomposition of water is an alternative.
The problem is that the water is only 1% decomposing.
No single reaction in the cycle would need a high temperature.
Another alternative is the use of solar energy to break down water.
The bulk of the gas makes it difficult to store.
The H21l2 needs to be stored at very low temperatures because of its low boiling point.
Out of contact with oxygen or air, hydrogen must be maintained.
One approach to dissolving H21g2 is in a metal or metal alloy.
Mild heating can release the gas.
The storage system would replace the gasoline tank in an automobile.
The heat needed to release hydrogen from the metal comes from the engine exhaust.
If the problems can be solved, hydrogen could be used to replace gasoline as a fuel for transportation and natural gas could be used for space heating.
Because H2 is a good reducing agent, it could replace carbon in metallurgical processes and, of course, it would be available for reaction with N2 to produce NH3 for the manufacture of fertilizers.
Ozone plays a vital role in protecting life on Earth because it absorbs potentially harmful ultraviolet radiation and also helps to maintain a heat balance in the atmosphere.
For a discussion of some ozone producing and ozone destroying reactions occurring in the atmosphere, and the impact made by human activities, go to the Focus On feature for Chapter 22, The Ozone Layer and Its Environmental Role.
The failure of fluorine to form stable fluorides changes from ionic bonding to covalent bond oxoacids.
The oxygen we pass through a group of elements that react with fluo family includes two reactive nonmetals rine to give network covalent compounds.
As we move left to right and second member of the group, the acid-base char notes the difference in properties between the first acter of the oxides and the second acter.
It is possible to form across the table.
The important acids H2SO4 are derived from elements in groups 2 and 13.
The progression of properties of F and O is shown in the chemistry of this 22-5 Group 15: The Nitrogen Family.
The istry of nitrogen and phosphorus is wide and diverse.
Some of the noble gases are impli ing the phosphates.
A reduction element that does not fit into any group has electrode potentials.
There are several differences between the first and ing nonpolluting means of storing, transporting, and using higher members of a group of the periodic table.
Data from the Edegcell reaction must be carefully prepared for use in analytical chemistry.
The solutions must be Figure 22-13.
The Edeg value for the reduction is given by that figure.
Decreases into SO21g2 and S 81s2.
When a solution of Na2S2O3 is acidified, the 2 S 2-1aq2 + 2 H sulfur is formed.
The basic solution has a V of 0.400 V tion.
Edegcell can be calculated now.
Write the half-equations and an overall equa Edegcell for the disproportionation reaction.
Determine Edegcell to find out if the reaction is spontaneously for standard-state conditions in acidic solution.
The disproportionation is likely to be more random or less random in acidic solution.
Increasing OH-4, as would be the case in making the solution basic, means decreasing 3H+4.
Assume that there are standard-state conditions.
Assume that there are standard-state conditions.
For these fluorides, you can describe the bismuth(III) as P4O6, Sb4O6, and Bi2O3.
As we move from these oxides, there is only one variation in bonding.
Which of these were left to right.
The oxides of selenium and tellurium are dation states.
One of these oxides is amphoteric P, S, and Cl, which gives the formula of the highest oxidation and one is acidic.
As we move from left to right, there is a variation in bonding.
There is a 55 L cylinder with Ar.
The XeF4 minimum volume of air must have been liquefied to yield XeO3, Xe, O2, and HF as products.
Write an equation for the hydrolysis in alka by volume.
XeF + 5.
CaF2 is the main source of fronine.
The by-product of a plausible chemical reaction can be fluoroine.
2 HOCl1aq2 HClO21aq2 + H+1aq2 + Cl-1aq2 Gen elements, F2, Cl2, or I2, will be written for standard halogens from a solution of halide ion.
There is a method that could be used to extract fluorine from the water.
A Lewis structure is not very stable in a solution.
Ozone is a powerful oxidizer.
Write equations to represent oxidation of structure on page 432 and estimate the average bond energy in O31g2 from the oxidant.
O3 has diamagnetic properties.
O21g2 5 * 1012 O3 molecule cm-3 is produced by each of the following compounds.
A temperature of 220 K is assumed.
Oxygen gas can be obtained in the laboratory but not in the water.
O21g2 was collected at 20.0 degC at an oxygen partial of oxygen, which was measured at 25 degC and 101 kPa.
The British chemist was credited with water.
The discovery of oxygen in 1774.
O2(aq) is a strong base in water.
Give an example of a chemical equation that reduced in size.
A sample of natural gas was measured at 25 degrees.
If a white solid is Na2SO4 or Na2S2O3 what is the oxidation state of sulfur?
Information from this chapter and previous tant commercial reactions involving nitrogen can be used to write chemical equations.
When heated, each of the following substances break down to the products indicated.
Balance nitrogen and dinitrogen monoxide equations are needed for these reactions.
The unsymmetrical dimethylhydrazine, 1CH322NNH2 reaction requires a balanced equation.
The concentration of HNO31aq2 used in laboratories is usually a mixture of sodium dihydrogenphosphate and 15 M HNO3 and has a density of 1.41 g mL-1.
What is it called?
Draw plausible Lewis structures for these two and nitrogen monoxide to produce gaseous nitrogen substances.
Edeg is the reduction of 102.5 degC.
The struc N2O4 should be rationalized in an acidic solution.
The only group 15 element that does not form a trifluoride is the NF3 molecule Gen.
Provide an explanation.
The boiling points of oxygen and argon are 755 and 189 degrees Centigrade, with H2O1g2 and collected at 23 and 755 degrees Centigrade, respectively.
The solution is 20.5mmHg.
There is excess hydrogen added to the mixture.
The results shown are different.
The hot copper(II) oxide is passed over the mixture.
The dehydrated material is passed over the mixture from step 2.
Estimate the bond angles by drawing Lewis structures.
If no attempt is made to separate the H21g2 and O21g2 produced by the water, what will happen?
The NH Appendix D can be used to estimate the percent dissociation of Cl21g2 into NH31g2 at 1 atm total pressure and 1000 K.
The unreacted HCl can be measured with NaOH.
A sample of nitrate solution was oxidation by H2O2.
It is treated with zinc in the basic solution.
Oxygen atoms are an important component of the arrangement of N and Si atoms.
At 1500 K, propose bonding lational kinetic energy of O atoms.
C 3.5 was treated with Cl21g2.
Write a bal of the seawater adjusted with H2SO4 and the anced equation for the reaction of dini trogen monoxide.
Despite the fact that it has a higher mass.
Give a plausible explanation for the observation.
The text says that bromine would be taken from the explosion hazard with the help of an Ammonia perchlorate.
The reaction that occurs is represented by 2 tion(s).
The solution is still acidic.
The data can be used to explain why XeF2 is more stable than 2.
Polonium is the only element that can be seen in the oxidation-reduction equation.
In this structure, the inter ation of XeF4 to Xe and XeO3 in acidic solu atomic distance between a Po atom and each of its tion.
Six nearest neighbors are 335 pm and Xe and XeO3 are produced in a 2 mole ratio.
O21g2 is also produced if you use this description.
The Edeg value is given in a handbook.
The following species H2S1g2 is arranged in Figure 11-25.
The basis of your expectation should be stated.
Some of the chlorine is found in the destruction of the ozone layer.
Edeg's phate of lime was -3.09 V.
Edeg is for the reduction of HN3 to NH4 in acidic 2.185.
The central halogen atom, X, assigns formal charges to the atoms in your structures.
Refer to Figure 22-3 to construct Draw Lewis structures and predict the geometries of diagram for forming XeO31g2 from Xe(g) and O21g2.