Chemistry Chapters 8&9

The decomposition of potassium chlorate, KClO3, into KCl and O2, is used as a source of oxygen in the laboratory. How many moles of potassium chlorate are needed to produce 15 mol of oxygen gas?

10 mol KClO3

Decomposition reaction

a compound breaks down into 2 or more simpler substances -only one reactant AB > A + B *products: -binary: break into elements -others: hard to tell Ex.) 2H2O(l) > 2H2(g) + O2(g)

Combustion reaction

the burning of any substance in O2 to produce heat A + O2 > B *products: -contain oxygen -hydrogcarbons form CO2 + H2O Ex.) CH4(g) + 2O2(g) > CO2(g) + 2H2O(g)

What mass of aluminum is produced by the decomposition of 5.0 kg Al2O3?

2.6 kg Al

Methanol can be produced through the reaction of CO and H2 in the presence of a catalyst. CO(g) + 2H2(g) ⟶ catalyst CH3OH(l) If 75.0 g of CO react to produce 68.4 g CH3OH, what is the percentage yield of CH3OH?

79.7%

When magnesium burns in air, it combines with oxygen to form magnesium oxide according to the following equation. 2Mg(s) + O2(g) > 2MgO(s) What mass in grams of magnesium oxide is produced from 2.00 mol of magnesium?

80.6 g MgO

Write balanced equation: solid calcium reacts with water to produce aqueous calcium hydroxide and hydrogen gas.

Ca(s) + 2H2O(l) > Ca(OH)2(aq) + H2(g)

Write word and equation: Solid calcium reacts with solid sulfur to produce solid calcium sulfide.

Calcium + sulfur > calcium sulfide Ca(s) + S(s) > CaS(s)

Hydrazine, N2H4, is used as rocket fuel. Hydrazine reacts violently with oxygen to produce gaseous nitrogen and water. Write balances equation.

N2H4(l) + O2(g) > N2(g) + 2H2O(l)

Identify the element that displaced hydrogen from acids but cannot displace Tin from its compounds.

Pb

Using activity series predict whether the reactions will occur. For these reactions write products and balance equation

Pt(s) + O2(g) > No

Aluminum reacts with excess copper(II) sulfate according to the reaction given below. If 1.85 g of Al react, and the percentage yield of Cu is 56.6%, what mass of Cu is produced? Al(s) + CuSO4(aq) → Al2(SO4)3(aq) + Cu(s) (unbalanced)

3.70 g Cu

Translate into words: FeS(s) + HCL(aq) > FeCl2(s) + H2S(g)

Solid iron(II) sulfide and aqueous solution of hydrochloric acid react to produce solid iron(II) chloride and gaseous hydrogen sulfide.

Write word, formula, and equation: Solid magnesium and aqueous hydrochloric acid react to produce aqueous magnesium chloride and hydrogen gas.

Word: magnesium + hydrochloric acid > magnesium chloride + hydrogen Formula: Mg(s) + HCL(aq) > MgCl2(aq) + H2(g) Balanced: Mg(s) + 2HCL(aq) > MgCl2(aq) + H2(g)

Single Replacement

one element replaces another in a compound -metal replaces metal -nonmetal replaces nonmetal A + BC > B + AC *products: -metal > metal -nonmetal > nonmetal -free element must be more active Ex.) Cu(s) + 2AgNO3(aq) > Cu(NO3)2(aq) + 2Ag(s)

Solid calcium metal reacts with water to form aqueous calcium hydroxide and hydrogen gas. Write a balanced chemical quark in for this reaction.

Ca(s) + 2H2O(l) > Ca(OH)2(aq) + H2(g)

Using activity series predict whether the reactions will occur. For these reactions write products and balance equation

Cd(s) + 2HBr(aq) > Yes; Cd(s) + 2HBr(aq) > CdBr2(aq) + H2(g)

Using activity series predict whether the reactions will occur. For these reactions write products and balance equation:

Cr(s) + H2O(l) > No

Using activity series predict whether the reactions will occur. For these reactions write products and balance equation

Mg(s) + steam > Yes; Mg(s) + 2H2O(g) > Mg(OH)2(aq) + H2(g)

Write word, equation, and formula: Aqueous nitric acid reacts with sold magnesium hydroxide to produce aqueous magnesium nitrate and water.

Word: nitric acid + magnesium hydroxide > magnesium nitrate + water Formula: HNO3(aq) + Mg(OH)2(s) > Mg(NO3)2(aq) + H2O(l) Balanced: 2HNO3(aq) + Mg(OH)2(s) > Mg(NO3)2(aq) + 2H2O(l)

Mole ratio

a conversion factor that relates the amounts in moles of any two substances involved in a chemical reaction.

Some rocket engines use a mixture of hydrazine, N2H4, and hydrogen peroxide, H2O2, as the propellant. The reaction is given by the following equation. N2H4(l) + 2H2O2(l) → N2(g) + 4H2O(g) a. Which is the limiting reactant in this reaction, when 0.750 mol N2H4 is mixed with 0.500 mol H2O2? b. How much of the excess reactant, in moles, remains unchanged? c. How much of each product, in moles, is formed?

a. H2O2 b. 0.500 mol N2H4 c. 0.250 mol N2, 1.00 mol H2O

1. Zinc and sulfur react to form zinc sulfide according to the following equation. 8Zn(s) + S8(s) → 8ZnS(s) a. If 2.00 mol of Zn are heated with 1.00 mol of S8, identify the limiting reactant. b. How many moles of excess reactant remain? c. How many moles of the product are formed?

a. Zn b. 0.75 mol S8 remains c. 2.00 mol ZnS

Carbon reacts with steam, H2O, at high temperatures to produce hydrogen and carbon monoxide. a. If 2.40 mol of carbon are exposed to 3.10 mol of steam, identify the limiting reactant. b. How many moles of each product are formed? c. What mass of each product is formed?

a. carbon b. 2.40 mol H2 and 2.40 mol CO c. 4.85 g H2 and 67.2 g CO

Laughing gas (nitrous oxide, N2O) is sometimes used as an anesthetic in dentistry. It is produced when ommonium nitrate is decomposed according to the following reaction. NH4NO3(s) > N2O(g) + 2H2O(l) How many grams of NH4NO3 are required to produce 33.0 g N2O? How many grams of water are produced in this reaction?

a.) 60.0 g NH4NO3 b.) 27.0 g H2O

Double replacement

ions in two compounds change partners -cation of one compound combines with anion of the other AB + CD > AD + CB *products: -switch negative ions -one product must be insoluble Ex.) Pb(NO3)2(aq) + K2CrO4(aq) > PbCrO4(s) + 2KNO3(aq)

Write balanced equation: When solid copper reacts with aqueous silver nitrate, the products are aqueous copper(II) nitrate and solid silver

.Cu(s) + 2AgNO3(aq) > Cu(NO3)2(aq) + 2Ag(s)

What mass of glucose can be produced from a photosynthesis reaction that occurs using 10 mol CO2? 6CO2(g) + 6H2O(l) > C6H12O6(aq) + 6O2(g)

300 g C6H12O6

When copper metal is added to silver nitrate in soultion, silver metal and copper(II) nitrate are produced. What mass of silver is produced from 100. g Cu?

339 g Ag

Ammonia, NH3, is widely used as a fertilizer and as an ingredient in many household cleaners. How many moles of ammonia are produced when 6 mil of hydrogen gas reacts with an excess of nitrogen gas?

4 mol NH3

Write word and equation: Solid aluminum metal reacts with aqueous zinc chloride to produce solid zinc metal and aqueous aluminum chloride.

Aluminum + zinc chloride > zinc + aluminum chloride 2Al(s) + 3ZnCl2(aq) > 3Zn(s) + 2AlCl3(aq)

Translate into words: 3KOH(aq) + H3PO4(aq) > K3PO4(aq) + 3H2O(l)

Aqueous solutions of potassium hydroxide and phosphoric acid react to produce potassium phosphate in aqueous solution and water

Write balanced equation: in a blast furnace, the reaction between solid iron(III) oxide and carbon monoxide gas produces solid iron and carbon dioxide gas

Fe2O3(s) + 3CO(g) > 2Fe(s) + 3CO2(g)

Write word and equation: Hydrogen gas reacts with fluorine gas to produce hydrogen fluoride gas.

Hydrogen + fluorine > hydrogen fluoride H2(g) + F2(g) > 2HF(g)

According to figure 3.1 what is the most active transition element

Mn

Oxygen was discovered by Joseph Priestley in 1774 when he heated mercury(II) oxide to decompose it to form its constituent elements. How many moles of mercury(II) oxide, HgO, are needed to produce 125 g of oxygen, O2? How many moles of mercury are produced?

a.) 7.81 mol HgO b.) 7.81 mol Hg

Synthesis Combustion

the combination of 2 or more substances to form a compound -only one product A + B > AB Ex.) H2(g) + Cl(g) > 2HCl(g)