These are homework exercises to accompany the Textmap created for "Chemistry" by OpenStax. Complementary General Chemistry question banks can be found for other Textmaps and can be accessed here. In addition to these publicly available questions, access to private problems bank for use in exams and homework is available to faculty only on an individual basis; please contact Delmar Larsen for an account with access permission. In the following drawing, the green spheres represent atoms of a certain element.
The purple spheres represent atoms of another element. If the spheres of different elements touch, they are part of a single unit of a compound. Which one? The starting materials consist of one green sphere and two purple spheres.
The products consist of two green spheres and two purple spheres. When grams of solid calcium carbonate is heated, 44 grams of carbon dioxide and 56 grams of calcium oxide are produced.
Do these data provide example s of the law of definite proportions, the law of multiple proportions, neither, or both?
What do these data tell you about compounds X, Y, and Z? Thus, the concept of isotopes, in which an element has different masses, was a violation of the original idea. To account for the existence of isotopes, the second postulate of his atomic theory was modified to state that atoms of the same element must have identical chemical properties.
Both have approximately the same mass. Protons are positively charged, whereas neutrons are uncharged. In what way are isotopes of a given element always different? In what way s are they always the same? Open the Build an Atom simulation and click on the Atom icon. There are six electrons in a neutral 12 C atom. The net charge of such a neutral atom is zero, and the mass number is Other answers for this exercise are possible if a different element of isotope is chosen.These are homework exercises to accompany the Textmap created for "Chemistry" by OpenStax.
Complementary General Chemistry question banks can be found for other Textmaps and can be accessed here.
In addition to these publicly available questions, access to private problems bank for use in exams and homework is available to faculty only on an individual basis; please contact Delmar Larsen for an account with access permission.
The protons in the nucleus do not change during normal chemical reactions.
Only the outer electrons move. Positive charges form when electrons are lost. Explain why a sample of iron III sulfate is uncharged.
Which of the following atoms would be expected to form negative ions in binary ionic compounds and which would be expected to form positive ions: P, I, Mg, Cl, In, Cs, O, Pb, Co? P, I, Cl, and O would form anions because they are nonmetals.
Mg, In, Cs, Pb, and Co would form cations because they are metals. Which of the following atoms would be expected to form negative ions in binary ionic compounds and which would be expected to form positive ions: Br, Ca, Na, N, F, Al, Sn, S, Cd? Predict the charge on the monatomic ions formed from the following atoms in binary ionic compounds:. Write the electron configuration for the monatomic ions formed from the following elements which form the greatest concentration of monatomic ions in seawater :.
Write out the full electron configuration for each of the following atoms and for the monatomic ion found in binary ionic compounds containing the element:. From the labels of several commercial products, prepare a list of six ionic compounds in the products. For each compound, write the formula. You may need to look up some formulas in a suitable reference. Predict which of the following compounds are ionic and which are covalent, based on the location of their constituent atoms in the periodic table:.
Explain the difference between a nonpolar covalent bond, a polar covalent bond, and an ionic bond. From its position in the periodic table, determine which atom in each pair is more electronegative:. From their positions in the periodic table, arrange the atoms in each of the following series in order of increasing electronegativity:.
Many monatomic ions are found in seawater, including the ions formed from the following list of elements. Write the Lewis symbols for the monatomic ions formed from the following elements:. Write the Lewis symbols of the ions in each of the following ionic compounds and the Lewis symbols of the atom from which they are formed:.
In the Lewis structures listed here, M and X represent various elements in the third period of the periodic table. Write the formula of each compound using the chemical symbols of each element:.
Write the Lewis structure for the diatomic molecule P 2an unstable form of phosphorus found in high-temperature phosphorus vapor. In this case, the Lewis structure is inadequate to depict the fact that experimental studies have shown two unpaired electrons in each oxygen molecule.
Thus, all of the valence electrons in PbCl 2 are located on the Cl — ions, and all of the valence electrons in a HCl molecule are shared between the H and Cl atoms. Two of the valence electrons in the HCl molecule are shared, and the other six are located on the Cl atom as lone pairs of electrons. Methanol, H 3 COH, is used as the fuel in some race cars. Both methanol and ethanol produce CO 2 and H 2 O when they burn. Write the chemical equations for these combustion reactions using Lewis structures instead of chemical formulas.
Write the Lewis structures for each of these molecules. Carbon tetrachloride was formerly used in fire extinguishers for electrical fires.What does it mean to say an equation is balanced?
Why is it important for an equation to be balanced? Write a balanced molecular equation describing each of the following chemical reactions. Write a balanced equation describing each of the following chemical reactions.
Colorful fireworks often involve the decomposition of barium nitrate and potassium chlorate and the reaction of the metals magnesium, aluminum, and iron with oxygen. Write an equation for the reaction. Fill in the blank with a single chemical formula for a covalent compound that will balance the equation:. Aqueous hydrogen fluoride hydrofluoric acid is used to etch glass and to analyze minerals for their silicon content.
Hydrogen fluoride will also react with sand silicon dioxide. Solid calcium fluoride can also be prepared by the reaction of aqueous solutions of calcium chloride and sodium fluoride, yielding aqueous sodium chloride as the other product.
Write complete and net ionic equations for this reaction. A novel process for obtaining magnesium from sea water involves several reactions.
Write a balanced chemical equation for each step of the process. From the balanced molecular equations, write the complete ionic and net ionic equations for the following:.
7: Chemical Bonding (Exercises)
Silver can be separated from gold because silver dissolves in nitric acid while gold does not. Is the dissolution of silver in nitric acid an acid-base reaction or an oxidation-reduction reaction?
Explain your answer. Determine the oxidation states of the elements in the compounds listed. None of the oxygen-containing compounds are peroxides or superoxides. Classify the following as acid-base reactions or oxidation-reduction reactions:. Identify the atoms that are oxidized and reduced, the change in oxidation state for each, and the oxidizing and reducing agents in each of the following equations:. Complete and balance the following oxidation-reduction reactions, which give the highest possible oxidation state for the oxidized atoms.
Complete and balance the equations for the following acid-base neutralization reactions. If water is used as a solvent, write the reactants and products as aqueous ions.
In some cases, there may be more than one correct answer, depending on the amounts of reactants used. They burn! Write the balanced equation for this reaction. The military has experimented with lasers that produce very intense light when fluorine combines explosively with hydrogen.
What is the balanced equation for this reaction? Write the molecular, total ionic, and net ionic equations for the following reactions:.
Great Lakes Chemical Company produces bromine, Br 2from bromide salts such as NaBr, in Arkansas brine by treating the brine with chlorine gas.
Write a balanced equation for the reaction of NaBr with Cl 2. In a common experiment in the general chemistry laboratory, magnesium metal is heated in air to produce MgO. MgO is a white solid, but in these experiments it often looks gray, due to small amounts of Mg 3 N 2a compound formed as some of the magnesium reacts with nitrogen. Write a balanced equation for each reaction.
Lithium hydroxide may be used to absorb carbon dioxide in enclosed environments, such as manned spacecraft and submarines. Hint: Water is one of the products.Write equations that show NH 3 as both a conjugate acid and a conjugate base.
What is the conjugate acid of each of the following? What is the conjugate base of each? State which of the following species are amphiprotic and write chemical equations illustrating the amphiprotic character of these species:. State which of the following species are amphiprotic and write chemical equations illustrating the amphiprotic character of these species. Is the self-ionization of water endothermic or exothermic?
The ionization constant for water K w is 2. The ionization constant for water K w is 9. What are the pH and pOH of a solution of 2. What are the hydronium and hydroxide ion concentrations in a solution whose pH is 6.
Calculate the hydrogen ion concentration and the hydroxide ion concentration in wine from its pH. See Figure Calculate the hydronium ion concentration and the hydroxide ion concentration in lime juice from its pH. The hydronium ion concentration in a sample of rainwater is found to be 1.15. Hydrocarbons - Exercise Solutions (Part 2) : Chemistry Class 11th Mahrashtra State Board New
What is the concentration of hydroxide ions in the rainwater? The hydroxide ion concentration in household ammonia is 3. What is the concentration of hydronium ions in the solution?
Explain why the neutralization reaction of a strong acid and a weak base gives a weakly acidic solution.
Explain why the neutralization reaction of a weak acid and a strong base gives a weakly basic solution. Use this list of important industrial compounds and Figure List, in order of descending concentration, all of the ionic and molecular species present in a 1- M aqueous solution of this acid.
Household ammonia is a solution of the weak base NH 3 in water. List, in order of descending concentration, all of the ionic and molecular species present in a 1- M aqueous solution of this base.
Gastric juice, the digestive fluid produced in the stomach, contains hydrochloric acid, HCl. Milk of Magnesia, a suspension of solid Mg OH 2 in an aqueous medium, is sometimes used to neutralize excess stomach acid. Write a complete balanced equation for the neutralization reaction, and identify the conjugate acid-base pairs. Nitric acid reacts with insoluble copper II oxide to form soluble copper II nitrate, Cu NO 3 2a compound that has been used to prevent the growth of algae in swimming pools.
Predict which acid in each of the following pairs is the stronger and explain your reasoning for each. Predict which compound in each of the following pairs of compounds is more acidic and explain your reasoning for each. Rank the compounds in each of the following groups in order of increasing acidity or basicity, as indicated, and explain the order you assign.
The phenol group an OH group bonded to an aromatic ring also acts as an acid but a much weaker acid. List, in order of descending concentration, all of the ionic and molecular species present in a 0.Write a sentence that describes how to determine the number of moles of a compound in a known mass of the compound using its molecular formula.
Which contains the greatest mass of oxygen: 0. Explain why. How are the molecular mass and the molar mass of a compound similar and how are they different? Calculate the empirical or molecular formula mass and the molar mass of each of the following minerals:.
Determine the number of moles of compound and the number of moles of each type of atom in each of the following:. Determine the number of moles of the compound and determine the number of moles of each type of atom in each of the following:. The approximate minimum daily dietary requirement of the amino acid leucine, C 6 H 13 NO 2is 1. What is this requirement in moles? A kg woman has 7. How many hemoglobin molecules is this? What is this quantity in grams?
Determine the number of atoms and the mass of zirconium, silicon, and oxygen found in 0. Determine which of the following contains the greatest mass of hydrogen: 1 mol of CH 40. Diamond is one form of elemental carbon. An engagement ring contains a diamond weighing 1. How many atoms are present in the diamond? The Cullinan diamond was the largest natural diamond ever found January 25, How many carbon atoms were present in the stone?
How many moles and atoms of sodium are in the recommended daily allowance? A certain nut crunch cereal contains How many servings of this cereal must be eaten to consume 0. A tube of toothpaste contains 0. What information is needed to determine the molecular formula of a compound from the empirical formula? Determine the empirical formulas for compounds with the following percent compositions:. A compound of carbon and hydrogen contains What is its molecular formula? Dichloroethane, a compound that is often used for dry cleaning, contains carbon, hydrogen, and chlorine.
Analysis of a sample shows that it contains Determine the empirical and molecular formula for chrysotile asbestos. Chrysotile has the following percent composition: Dead-HeatsWhere two selections dead-heat half the stake money is lost and the full odds are paid to the other half. If more than two dead-heat the stake is proportioned accordingly. FavouritesWagers will be accepted win only at starting price for 1st and 2nd favourites.
The Place part of any wager inadvertently accepted for unnamed favourites will be settled as a Win stake. In the event of two selections starting joint favourites then stakes are divided equally. Where three or more selections start co-favourites stakes will be divided proportionately. However, if such joint favourites or co-favourites are returned at a price whereby, irrespective of result, no profit could be accrued by the backer of the favourite, the unnamed favourite will be treated as a non-runner, in both single and accumulative bets.
Should the favourite be withdrawn before coming under starter's orders but too late for a new market to be formed then bets on the favourite in that particular race are void.
In the event a joint or co-favourite being withdrawn then the proportion of stakes on that selection will be void and the remaining proportion of stakes will be divided equally on the selections that do run. Forecast BettingForecasts are accepted for all races of 3 or more actual runners and will be settled as a straight forecast (selections to finish 1st and 2nd in correct order) in accordance with the computer straight forecast dividend.
If there are less than 3 actually running in a race then all forecasts for that race will be void. In the event of no straight forecast dividend being declared then forecasts will be settled in accordance with the NSL straight forecast chart provided that 3 or more actually run in that race.
You may take early prices or show prices in straight forecasts when available, in a fixed price forecast. Where a client selects combination forecasts A B C and stakes for 6 bets this will be settled as 6 straight forecasts as follows:Should any forecast contain a non-runner then the total stake will be placed to Win on the other selection.
In fixed price forecasts the remaining selection will be settled at SP. In races where a horse finishes alone and no forecast dividend is returned then all forecast bets nominating that horse to finish first will be settled as a Win single at SP on the winning horse.
All other forecast bets in the race are lost. In the event of two or more horses dead-heating for first or second place then separate dividends will be declared and paid to each qualifying forecast.
In fixed price forecasts the full odds will be paid with the stake split according to the number of horses which dead-heat. Tricast BettingYou may take early prices or show prices in straight Tricasts when available, in a fixed price Tricast.
This is available on all horse races of 8 or more runners. However, if no computer Tricast dividend is declared (e. The following applies to both Tricasts and fixed price Tricasts: if one selection is a non-runner then the bet will be settled as a straight forecast at the computer forecast dividend. If there are two non-runners then the bet will be settled as an SP single on the remaining selection.
In the event of two or more horses dead-heating for first, second or third place then separate dividends will be declared and paid to each qualifying tricast. In fixed price tricasts the full odds will be paid with the stake split according to the number of horses which dead-heat.
Tricasts are accepted for singles only. Rule 4 (Deductions) will apply. ReservesIn races with reserves, any bets taken prior to a reserve horse being declared to run and if the reserve was not priced up at the time the bet was placed, then any such bets will be settled on the result 'without the reserve runner(s)'.
Each way bets settled on the result "without the reserve runner(s)" will be based on the number of runners, excluding reserves, that start the race.Breakfasts at all hotels excellent.
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