Chemistry Chemistry Practice Problems Solutions Library

Stoichiometry Solutions Library

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333 solutions

Stoichiometry

Q. If 12.0g of MgSO4 • 7H2O is thoroughly heated, what mass of anhydrous magnesium sulfate will remain? Express your answer to three significant figur...

Solved • Mar 18, 2020

Stoichiometry

Q. When heated, KCIO3 decomposes into KCI and O2. 2KCIO3 → 2KCl+ 3O2 If this reaction produced 50.6 g of KCI, how much O2 was produced (in grams)?

Solved • Mar 17, 2020

Stoichiometry

Q. In a chemical reaction, exactly 2 mol of substance A react to produce exactly 3 mol of substance B. 2 A → 3B How many molecules of substance B are ...

Solved • Mar 17, 2020

Stoichiometry

Q. Determine the mass of oxygen in a 7.2-g sample of Al2(SO4)3. Express the mass in grams to two significant figures.

Solved • Mar 17, 2020

Stoichiometry

Q. Automotive air bags inflate when sodium azide, NaN3, rapidly decomposes into its component elements:2 NaN3(s) → 2 Na(s) + 3 N2(g)How many grams of ...

Solved • Nov 28, 2019

Stoichiometry

Q. How many grams of oxygen are formed when 5.30 moles of KOH are formed?4 KO(s) + 2 H2O(l) → 4 KOH(s) + O2(g) A) 21.2 g O2B) 84.8 g O2C) 170 g O2D) 5...

Solved • Oct 25, 2019

Stoichiometry

Q. Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements:2NaN3(s) → 2Na(s) + 3N2(g)How many grams of sodium...

Solved • Oct 25, 2019

Stoichiometry

Q. The formation of ammonia can be written as N2(g) + 3 H2(g) → 2NH3(g)How much ammonia is produced if 14.0 g of N2(g) is reacted with excess hydrogen...

Solved • Oct 3, 2019

Stoichiometry

Q. Consider the following reaction: 2 Al + 6 HCl → Al2Cl6 + 3 H2How many moles of HCl are required to produce 2.6 moles of hydrogen? Assume that there...

Solved • Oct 2, 2019

Stoichiometry

Q. Calcium carbide, CaC2, is an important preliminary chemical for industries producing synthetic fabrics and plastics. CaC2 may be produced by heatin...

Solved • Oct 1, 2019

Stoichiometry

Q. How many individual ions are in 18.2 grams of Al2S3?A. 7.30 × 1023 ions      B. 1.85 × 10 23 ions      C. 9.28 × 10 23 ions      D. 3.65 × 10 23 io...

Solved • Sep 18, 2019

Stoichiometry

Q. Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2): CaC2 (s) + 2 H2O (g) → Ca(OH)2 (s) + C2H2 (g)Production of 13 g of C2H2 requi...

Solved • Sep 13, 2019

Stoichiometry

Q. Given the following reaction:2H2O2 → 2H2O + O2How many moles of H2O will be produced from 42.0 g of H 2O2?_____ moles (round to three significant f...

Solved • Aug 25, 2019

Stoichiometry

Q. Balance the equation and solve the following questions.CH3CH3 + O2 → CO2 + H2Oa) How many moles of CH3CH3 are in 13.50g of CH3CH3b) If 13.50g of CH...

Solved • Aug 6, 2019

Stoichiometry

Q. How many grams of Li3N can be formed from 1.75 moles of Li? Assume an excess of nitrogen.6 Li(s) + N2(g) → 2 Li3N(s)a. 18.3 g Li3Nb. 58.3 g Li3Nc. ...

Solved • Aug 2, 2019

Stoichiometry

Q. Potassium hydroxide and phosphoric acid react to form potassium phosphate and water according to the equation.3KOH(aq) + H3PO4(aq) → K3PO4(aq) + 3H...

Solved • Jul 9, 2019

Stoichiometry

Q. When hydrochloric acid reacts with barium hydroxide, barium chloride and water are produced. The balanced equation for this reaction is: 2HCl (aq) ...

Solved • Jul 9, 2019

Stoichiometry

Q. Sodium reacts with oxygen to form sodium oxide and has the following balanced chemical equation: 4 Na + O2 → 2 Na 2O.How many mole(s) of oxygen gas...

Solved • Jul 9, 2019

Stoichiometry

Q. Chlorine reacts with oxygen to form Cl2O7 (l).PrefixMeaningMono-1Di-2Tri-3Tetra-4Penta-5Hexa-6Hepta-7Octa-8Nona-9Deca-10Write a balanced equation f...

Solved • Nov 12, 2018

Stoichiometry

Q. The organic molecules shown beloware derivatives of benzene in which additional six-membered rings are "fused" at the edges of the hexagons. The co...

Solved • Nov 12, 2018

Stoichiometry

Q. When magnesium metal is burned in air, two products are produced. One is magnesium oxide, MgO. The other is the product of the reaction of Mg with ...

Solved • Nov 12, 2018

Stoichiometry

Q. Potassium superoxide, KO2, is often used in oxygen masks (such as those used by firefighters) because KO2 reacts with CO2 to release molecular oxyg...

Solved • Nov 12, 2018

Stoichiometry

Q. Potassium superoxide, KO2, is often used in oxygen masks (such as those used by firefighters) because KO2 reacts with CO2 to release molecular oxyg...

Solved • Nov 12, 2018

Stoichiometry

Q. The ionic substance strontium oxide, SrO, forms from the direct reaction of strontium metal with molecular oxygen. The arrangement of the ions in s...

Solved • Nov 12, 2018

Stoichiometry

Q. An element X reacts with F2(g) to form the molecular product shown here. Write a balanced equation for this reaction (do not worry about the phase...

Solved • Nov 12, 2018

Stoichiometry

Q. Propane, C3H8, is a common fuel used for cooking and home heating. What mass of O2 is consumed in the combustion of 1.00 g of propane?

Solved • Oct 31, 2018

Stoichiometry

Q. The diagram  represents a high-temperature reaction between CH4 and H2O.Based on this reaction, find how many moles of CO can be obtained starting ...

Solved • Oct 31, 2018

Stoichiometry

Q. The diagram represents a high-temperature reaction between CH4 and H2O.Based on this reaction, how many moles of H2 can be obtained starting with 6...

Solved • Oct 31, 2018

Stoichiometry

Q. When a compound containing C, H, and O is completely combusted in air, what reactant besides the hydrocarbon is involved in the reaction?What produ...

Solved • Oct 31, 2018

Stoichiometry

Q. The decomposition of ZnCO3(s) into ZnO(s) and CO2(g) at constant pressure requires the addition of 71.5 kJ of heat per mole of ZnCO3.Write a balanc...

Solved • Oct 31, 2018

Stoichiometry

Q. Gasoline is composed primarily of hydrocarbons, including many with eight carbon atoms, called octanes. One of the cleanest-burning octanes is a co...

Solved • Oct 31, 2018

Stoichiometry

Q. Diethyl ether, C4H10O (l), a flammable compound that has long been used as a surgical anesthetic, has the structureCH3 - CH2 - O - CH2 - CH3The com...

Solved • Oct 31, 2018

Stoichiometry

Q. Burning methane in oxygen can produce three different carbon-containing products: soot (very fine particles of graphite), CO(g), and CO2(g).Write b...

Solved • Oct 31, 2018

Stoichiometry

Q. The source of oxygen that drives the internal combustion engine in an automobile is air. Air is a mixture of gases, which are principally N2 (~79%)...

Solved • Oct 31, 2018

Stoichiometry

Q. If an automobile travels 230 mi with a gas mileage of 21.5 mi/gal , how many kilograms of CO2 are produced? Assume that the gasoline is compose...

Solved • Oct 31, 2018

Stoichiometry

Q. A particular coal contains 2.5% sulfur by mass. When this coal is burned, the sulfur is converted into sulfur dioxide gas. The sulfur dioxide react...

Solved • Oct 31, 2018

Stoichiometry

Q. The fat stored in the hump of a camel is a source of both energy and water.Calculate the mass of H2O produced by metabolism of 2.2 kg of fat, assum...

Solved • Oct 31, 2018

Stoichiometry

Q. A mixture of N2 (g) and H2 (g) reacts in a closed container to form ammonia, NH3 (g). The reaction ceases before either reactant has been totally c...

Solved • Oct 31, 2018

Stoichiometry

Q. If 1.5 mol C2H5OH, 1.5 mol C3H8, and 1.5 mol CH3CH2COCH3 are completely combusted in oxygen, which produces the least number of moles of H2O? Explain.

Solved • Oct 31, 2018

Stoichiometry

Q. If 1.5 mol of each of the following compounds is completely combusted in oxygen, which one will produce the largest number of moles of H2O?C2H5OH, ...

Solved • Oct 31, 2018

Stoichiometry

Q. A 1.800-g sample of solid phenol (C6H5OH(s)) was burned in a bomb calorimeter, which has a total heat capacity of 11.66 kJ/oC. The temperature of t...

Solved • Oct 31, 2018

Stoichiometry

Q. Calcium hydride reacts with water to form calcium hydroxide (aqueous) and hydrogen gas.How many grams of calcium hydride are needed to form 4.750 g...

Solved • Oct 31, 2018

Stoichiometry

Q. When 1.57 mol O2 reacts with H2 to form H2O, how many moles of H2 are consumed in the process?

Solved • Oct 31, 2018

Stoichiometry

Q. Magnesium hydroxide, the active ingredient in milk of magnesia, neutralizes stomach acid, primarily HCl, according to the reaction: Mg(OH)2(aq) + 2...

Solved • Oct 31, 2018

Stoichiometry

Q. Calculate how many moles of NH3 form when each quantity of reactant completely reacts according to the equation:3N2H4 (l) → 4NH3(g) + N2(g)63.8 g N2H4

Solved • Oct 31, 2018

Stoichiometry

Q. People sometimes use sodium bicarbonate as an antacid to neutralize excess hydrochloric acid in an upset stomach.What mass of hydrochloric acid (in...

Solved • Oct 31, 2018

Stoichiometry

Q. Consider the following balanced equation:2 N2H4(g) + N2O4(g) → 3 N2(g) + 4 H2O(g)Complete the following table showing the appropriate number of mol...

Solved • Oct 31, 2018

Stoichiometry

Q. Consider the following balanced equation:2 N2H4(g) + N2O4(g) → 3 N2(g) + 4 H2O(g)Complete the following table showing the appropriate number of mol...

Solved • Oct 31, 2018

Stoichiometry

Q. Under certain conditions sodium can react with oxygen to form sodium oxide according to the reaction: 4 Na(s) + O2(g) → 2 Na2O(s)A flask contains t...

Solved • Oct 31, 2018

Stoichiometry

Q. Consider the balanced equation:SiO2(s) + 3C(s) → SiC(s) + 2CO(g)Complete the following table showing the appropriate number of moles of reactants a...

Solved • Oct 31, 2018

Stoichiometry

Q. Consider the balanced equation:SiO2(s) + 3C(s) → SiC(s) + 2CO(g)Complete the following table showing the appropriate number of moles of reactants a...

Solved • Oct 31, 2018

Stoichiometry

Q. Consider the balanced equation:SiO2(s) + 3C(s) → SiC(s) + 2CO(g)Complete the following table showing the appropriate number of moles of reactants a...

Solved • Oct 31, 2018

Stoichiometry

Q. The world burns approximately 3.7 x 1012 kg of fossil fuel per year.Use the combustion of octane as the representative reaction and determine the m...

Solved • Oct 31, 2018

Stoichiometry

Q. Hydrolysis of the compound B5H9 forms boric acid, H3BO3. Fusion of boric acid with sodium oxide forms a borate salt, Na2B4O7.Without writing comple...

Solved • Oct 31, 2018

Stoichiometry

Q. Manganese(IV) oxide reacts with aluminum to form elemental manganese and aluminum oxide:3 MnO2 + 4Al → 3 Mn + 2 Al2O3What mass of Al is required to...

Solved • Oct 31, 2018

Stoichiometry

Q. An important reaction that takes place in a blast furnace during the production of iron is the formation of iron metal and CO2 from Fe2O3 and CO.Fi...

Solved • Oct 31, 2018

Stoichiometry

Q. A mixture of C3H8 and C2H2 has a mass of 2.6 g. It is burned in excess O2 to form a mixture of water and carbon dioxide that contains 1.6 times as ...

Solved • Oct 31, 2018

Stoichiometry

Q. A particular kind of emergency breathing apparatus-often placed in mines, caves, or other places where oxygen might become depleted or where the ai...

Solved • Oct 31, 2018

Stoichiometry

Q. The reaction of NH3 and O2 forms NO and water. The NO can be used to convert P4 to P4O6, forming N2 in the process. The P4O6 can be treated with wa...

Solved • Oct 31, 2018

Stoichiometry

Q. Toilet bowl cleaners often contain hydrochloric acid to dissolve the calcium carbonate deposits that accumulate within a toilet bowl.What mass of c...

Solved • Oct 31, 2018

Stoichiometry

Q. The combustion of gasoline produces carbon dioxide and water. Assume gasoline to be pure octane (C8H18) and calculate the mass (in kg) of carbon di...

Solved • Oct 31, 2018

Stoichiometry

Q. Many home barbeques are fueled with propane gas (C3 H8 ).What mass of carbon dioxide (in kg) is produced upon the complete combustion of 18.9 L of ...

Solved • Oct 31, 2018

Stoichiometry

Q. Calculate how many moles of NO2 form when each quantity of reactant completely reacts.2N2O5(g) → 4NO2(g) + O2(g)3.01 kg N2O5

Solved • Oct 31, 2018

Stoichiometry

Q. Hydrobromic acid dissolves solid iron according to the following reaction:Fe(s) + 2HBr(aq) → FeBr2(aq) + H2(g)What mass of HBr (in g) would you nee...

Solved • Oct 31, 2018

Stoichiometry

Q. For each of the following precipitation reactions, calculate how many grams of the first reactant are necessary to completely react with 55.3 g of ...

Solved • Oct 31, 2018

Stoichiometry

Q. For each of the following precipitation reactions, calculate how many grams of the first reactant are necessary to completely react with 55.3 g of ...

Solved • Oct 31, 2018

Stoichiometry

Q. Consider the unbalanced equation for the combustion of hexane:C6H14(g) + O2(g) → CO2(g) + H2O(g)Determine how many moles of O2 are required to reac...

Solved • Oct 31, 2018

Stoichiometry

Q. Consider the unbalanced equation for the neutralization of acetic acid:HC2H3O2(aq) + Ba(OH)2(aq) → H2O(l) + Ba(C2H3O2)2(aq)Determine how many moles...

Solved • Oct 31, 2018

Stoichiometry

Q. Calculate how many moles of NO2 form when each quantity of reactant completely reacts.2N2O5(g) → 4NO2(g) + O2(g)2.6 mol N2O5

Solved • Oct 31, 2018

Stoichiometry

Q. Calculate how many moles of NO2 form when each quantity of reactant completely reacts.2N2O5(g) → 4NO2(g) + O2(g)7.0 mol N2O5

Solved • Oct 31, 2018

Stoichiometry

Q. Calculate how many moles of NO2 form when each quantity of reactant completely reacts.2N2O5(g) → 4NO2(g) + O2(g)16.2 g N2O5

Solved • Oct 31, 2018

Stoichiometry

Q. A mixture of carbon and sulfur has a mass of 9.0 g. Complete combustion with excess O2 gives 24.6 g of a mixture of CO2 and SO2.Find the mass of su...

Solved • Oct 31, 2018

Stoichiometry

Q. The combustion of 987.0 g of methane in the presence of excess oxygen produces 1.543 kg of carbon dioxide. What is the percent yield? (a) 56.8% (b)...

Solved • Oct 24, 2018

Stoichiometry

Q. When copper(II) sulfate pentahydrate (CuSO4•5H2O) is heated, it decomposes to the dehydrated form. The waters of hydration are released from the so...

Solved • Oct 24, 2018

Stoichiometry

Q. Calculate the mass (in g) of O2 consumed in the complete combustion of 41.6 g sample of C4H8O. (Hint, write the balanced equation.)

Solved • Oct 24, 2018

Stoichiometry

Q. Green plants use light from the Sun to drive photosynthesis. Photosynthesis is a chemical reaction in which water (H2O) and carbon dioxide (CO2) ch...

Solved • Oct 23, 2018

Stoichiometry

Q. How many moles of NaOH will react with 1 mole of H2SO4 in the below unbalanced reaction? NaOH + H2SO4 → H2O + Na2SO4 

Solved • Oct 23, 2018

Stoichiometry

Q. Coal power plants burn large amounts of coal, C(s), in an O2(g) atmosphere to generate electricity. The chemical reaction responsible for producing...

Solved • Oct 22, 2018

Stoichiometry

Q. What mass of Ca(OH)2 will react with 25.0 g of butanoic to form the preservative calcium butanoate according to the equation?

Solved • Oct 19, 2018

Stoichiometry

Q. A sample of gallium bromide, GaBr3, weighing 0.165 g was dissolved in water and treated with silver nitrate, AgNO3, resulting in the precipitation ...

Solved • Oct 19, 2018

Stoichiometry

Q. The toxic pigment called white lead, Pb3(OH)2(CO3)2, has been replaced in white paints by rutile, TiO2. How much rutile (g) can be prepared from 37...

Solved • Oct 19, 2018

Stoichiometry

Q. A compact car gets 37.5 miles per gallon on the highway. If gasoline contains 84.2% carbon by mass and has a density of 0.8205 g/mL, determine the ...

Solved • Oct 18, 2018

Stoichiometry

Q. In an accident, a solution containing 2.5 kg of nitric acid was spilled. Two kilograms of Na2CO3 was quickly spread on the area and CO2 was release...

Solved • Oct 18, 2018

Stoichiometry

Q. Urea, CO(NH2)2, is manufactured on a large scale for use in producing urea-formaldehyde plastics and as a fertilizer. What is the maximum mass of u...

Solved • Oct 18, 2018

Stoichiometry

Q. Automotive air bags inflate when a sample of sodium azide, NaN3, is very rapidly decomposed.2NaN3(s) ⟶ 2Na(s) + 3N2(g)What mass of sodium azide is ...

Solved • Oct 18, 2018

Stoichiometry

Q. Carborundum is silicon carbide, SiC, a very hard material used as an abrasive on sandpaper and in other applications. It is prepared by the reactio...

Solved • Oct 18, 2018

Stoichiometry

Q. What mass of silver oxide, Ag 2O, is required to produce 25.0 g of silver sulfadiazine, AgC10H9N4SO2, from the reaction of silver oxide and sulfadi...

Solved • Oct 18, 2018

Stoichiometry

Q. Silver is often extracted from ores such as K[Ag(CN)2] and then recovered by the reaction 2K[Ag(CN)2](aq) + Zn(s) ⟶ 2Ag(s) + Zn(CN)2(aq) + 2KCN(aq)...

Solved • Oct 18, 2018

Stoichiometry

Q. I2 is produced by the reaction of 0.4235 mol of CuCl2 according to the following equation: 2CuCl2 + 4KI ⟶ 2CuI + 4KCl + I 2.(b) What mass of  I2 is...

Solved • Oct 18, 2018

Stoichiometry

Q. I2 is produced by the reaction of 0.4235 mol of CuCl2 according to the following equation: 2CuCl2 + 4KI ⟶ 2CuI + 4KCl + I 2.(a) How many molecules ...

Solved • Oct 18, 2018

Stoichiometry

Q. Determine the number of moles and the mass requested for each reaction in each of the following:(c) The number of moles and the mass of sodium nitr...

Solved • Oct 18, 2018

Stoichiometry

Q. The zinc in a 1.343-g sample of a foot powder was precipitated as ZnNH  4PO4. Strong heating of the precipitate yielded 0.4089 g Zn2P2O7. Calculate...

Solved • Oct 17, 2018

Stoichiometry

Q. Consider the following unbalanced chemical equation for the combustion of pentane (C5H12):C5H12 (l) + O2 (g) → CO2 (g) + H2O (l)If 20.4 g of pentan...

Solved • Oct 17, 2018

Stoichiometry

Q. You have seven closed containers, each with equal masses of chlorine gas (Cl 2). You add 10.0 g of sodium to the first sample, 20.0 g of sodium to ...

Solved • Oct 17, 2018

Stoichiometry

Q. A 0.755-g sample of hydrated copper(II) sulfateCuSO4 • x H2Owas heated carefully until it had changed completely to anhydrous copper(II) sulfate (C...

Solved • Oct 17, 2018

Stoichiometry

Q. Aspirin (C9H8O4) is synthesized by reacting salicylic acid (C7H6O3) with acetic anhydride (C4H6O3). The balanced equation isC7H6O3 + C4H6O3 → C9H8O...

Solved • Oct 17, 2018

Stoichiometry

Q. Elixirs such as Alka-Seltzer use the reaction of sodium bicarbonate with citric acid in aqueous solution to produce a fizz:3 NaHCO3 (aq) + C6H8O7 (...

Solved • Oct 17, 2018

Stoichiometry

Q. The reusable booster rockets of the U.S. space shuttle employ a mixture of aluminum and ammonium perchlorate for fuel. A possible equation for this...

Solved • Oct 17, 2018

Stoichiometry

Q. When powdered zinc is heated with sulfur, a violent reaction occurs, and zinc sulfide forms: Zn(s) + S8(s) ⟶ZnS(s) [unbalanced] Some of the reactan...

Solved • Oct 16, 2018

Stoichiometry

Q. Ethanol (CH3CH2OH), the intoxicant in alcoholic beverages, is also used to make other organic compounds. In concentrated sulfuric acid, ethanol for...

Solved • Oct 16, 2018