Balancing Chemical Equations PDF

# Balancing Chemical Equations ## Name: Key ## Date: Balance the following chemical equations. | Equation | Balanced Equation | |---|---| | 1. Fe + H2SO4 → Fe2(SO4)3 + H2 | 2 Fe + 3 H2SO4 → 1 Fe2(SO4)3 + 3 H2 | | 2. CH4 + O2 → CO2 + H2O | 1 CH4 + 2 O2 → 1 CO2 + 2 H2O | | 3. SiCl4(l) + H2O(l) → Si...

# Balancing Chemical Equations ## Name: Key ## Date: Balance the following chemical equations. | Equation | Balanced Equation | |---|---| | 1. Fe + H2SO4 → Fe2(SO4)3 + H2 | 2 Fe + 3 H2SO4 → 1 Fe2(SO4)3 + 3 H2 | | 2. CH4 + O2 → CO2 + H2O | 1 CH4 + 2 O2 → 1 CO2 + 2 H2O | | 3. SiCl4(l) + H2O(l) → SiO2(s) + HCl(aq) | 1 SiCl4(l) + 2 H2O(l) → 1 SiO2(s) + 4 HCl(aq) | | 4. AgI + Na2S → Ag2S + NaI | 2 AgI + 1 Na2S → 1 Ag2S + 2 NaI | | 5. NH3 + O2 → NO + H2O | 4 NH3 + 5 O2 → 4 NO + 6 H2O | | 6. FeO3(s) + CO(g) → Fe(l) + CO2(g) | 1 FeO3(s) + 3 CO(g) → 1 Fe(l) + 3 CO2(g) | | 7. SiO2 + HF → SiF4 + H2O | 1 SiO2 + 4 HF → 1 SiF4 + 2 H2O | | 8. NaBr + Cl2 → NaCl + Br2 | 2 NaBr + 1 Cl2 → 2 NaCl + 1 Br2 | | 9. (NH4)3PO4 + Pb(NO3)4 → Pb3(PO4)4 + NH4NO3 | 4 (NH4)3PO4 + 3 Pb(NO3)4 → 1 Pb3(PO4)4 + 12 NH4NO3 | | 10. Mg(OH)2 + HCl → MgCl2 + H2O | 1 Mg(OH)2 + 2 HCl → 1 MgCl2 + 2 H2O | # Balancing Equations Worksheet ## Name: Key | Equation | Balanced Equation | |---|---| | 1) Na3PO4 + KOH → NaOH + K3PO4 | 1 Na3PO4 + 3 KOH → 3 NaOH + 1 K3PO4 | | 2) MgF2 + Li2CO3 → MgCO3 + LiF | 1 MgF2 + 1 Li2CO3 → 1 MgCO3 + 2 LiF | | 3) P4 + O2 → P2O3 | 1 P4 + 3 O2 → 2 P2O3 | | 4) RbNO3 + BeF2 → Be(NO3)2 + RbF | 2 RbNO3 + 1 BeF2 → 1 Be(NO3)2 + 2 RbF | | 5) AgNO3 + Cu → Cu(NO3)2 + Ag | 2 AgNO3 + 1 Cu → 1 Cu(NO3)2 + 2 Ag | | 6) CF4 + Br2 → CBг4 + F2 | 1 CF4 + 2 Br2 → 1 CBг4 + 2 F2 | | 7) HCN + CuSO4 → H2SO4 + Cu(CN)2 | 2 HCN + 1 CuSO4 → 1 H2SO4 + 1 Cu(CN)2 | | 8) GaF3 + Cs → CsF + Ga | 1 GaF3 + 3 Cs → 3 CsF + 1 Ga | | 9) BaS + PtF2 → BaF2 + PtS | 1 BaS + 1 PtF2 → 1 BaF2 + 1 PtS | | 10) N2 + H2 → NH3 | 1 N2 + 3 H2 → 2 NH3 | | 11) NaF + Br2 → NaBr + F2 | 2 NaF + 1 Br2 → 2 NaBr + 1 F2 | | 12) Pb(OH)2 + HCl → H2O + PbCl2 | 1 Pb(OH)2 + 2 HCl → 2 H2O + 1 PbCl2 | | 13) AlBr3 + K2SO4 → KBr + Al2(SO4)3 | 2 AlBr3 + 1 K2SO4 → 6 KBr + 1 Al2(SO4)3 | | 14) CH4 + O2 → CO2 + H2O | 1 CH4 + 2 O2 → 1 CO2 + 2 H2O | | 15) Na3PO4 + CaCl2 → NaCl + Ca3(PO4)2 | 2 Na3PO4 + 3 CaCl2 → 6 NaCl + 1 Ca3(PO4)2 | | 16) K + Cl2 → KCl | 2 K + 1 Cl2 → 2 KCl | | 17) Al + HCl → H2 + AlCl3 | 2 Al + 6 HCl → 3 H2 + 2 AlCl3 | | 18) N2 + F2 → NF3 | 1 N2 + 3 F2 → 2 NF3 | | 19) SO2 + Li2Se → SSe2 + Li2O | 1 SO2 + 2 Li2Se → 1 SSe2 + 2 Li2O | | 20) NH3 + H2SO4 → (NH4)2SO4 | 2 NH3 + 1 H2SO4 → 1 (NH4)2SO4 | # Types of Reactions There are 5 major types of reactions simplified by the following equations: - Synthesis/Combination: A + B → AB - Decomposition: AB → A + B - Combustion: ? + O2 → ? - Single Replacement: X + AB → XB + A or Y + AB → AY + B - Double Replacement: XY + AB → XB + AY ## Classify each of the following reactions: 1. Zn + Cl2 → ZnCl2: **Synthesis** 2. 2 H2S + 3 O2 → 2 SO2 + 2 H2O: **Combustion** 3. Cu + 2 AgNO3 → Cu(NO3)2 + 2 Ag: **Single Replacement** 4. Mg(OH)2 → MgO + H2O: **Decomposition** 5. CaCl2 + Na2SO4 → CaSO4 + 2 NaCl: **Double Replacement** 6. CaO + H2O → Ca(OH)2: **Synthesis** 7. Pb + 4 HCl → PbCl4 + 2 H2: **Single Replacement** 8. Li2O + CO2 → Li2CO3: **Synthesis** 9. SO2 + H2O → H2SO3: **Synthesis** 10. MgCO3 → MgO + CO2: **Decomposition** ## Classify each of the following reactions when only the reactants are given: 1. Mg + N2 →: **Synthesis** 2. C2H6 + O2 →: **Combustion** 3. Zn + CuCl2 →: **Single Replacement** 4. Ca + H2O →: **Synthesis** 5. AgNO3 + NaI →: **Double Replacement** 6. Fe(NO3)3 + LiOH →: **Double Replacement** 7. MgCO3 →: **Decomposition** 8. SO2 + H2O →: **Synthesis** 9. HI → : **Decomposition** 10. H2SO4 + LiOH →: **Double Replacement** # Types of Reactions Worksheet ## Balance the following equations and indicate the type of reaction taking place. | Equation | Balanced Equation | Type of reaction | |---|---|---| | 1) NaBr + H3PO4 → Na3PO4 + HBr | 3 NaBr + 1 H3PO4 → 1 Na3PO4 + 3 HBr | Double | | 2) Ca(OH)2 + Al2(SO4)3 → CaSO4 + Al(OH)3 | 3 Ca(OH)2 + 1 Al2(SO4)3 → 3 CaSO4 + 2 Al(OH)3 | Double | | 3) Mg + Fe2O3 → Fe + MgO | 3 Mg + 1 Fe2O3 → 2 Fe + 3 MgO | Single | | 4) C2H4 + O2 → CO2 + H2O | 1 C2H4 + 3 O2 → 2 CO2 + 2 H2O | Combustion | | 5) PbSO4 → PbSO3 + O2 | 1 PbSO4 → 1 PbSO3 + 1 O2 | Decomposition | | 6) NH3 + I2 → N2 + H2 | 2 NH3 + 3 I2 → 1 N2 + 6 H2 | Single | | 7) H2O + SO2 → H2SO4 | 1 H2O + 1 SO2 → 1 H2SO4 | Synthesis | | 8) H2SO4 + NH4OH → H2O + (NH4)2SO4 | 1 H2SO4 + 2 NH4OH → 2 H2O + 1 (NH4)2SO4 | Double | # Balancing and Word Equations ## Classify type of the following reactions: | Equation | Type of Reaction | |---|---| | 1. 2K(s) + Cl2(g) → 2KCl(s) | Synthesis | | 2. Fe2O3(s) + 2Al(s) → Al2O3(s) + 2Fe(s) | Single Replacement | | 3. 2Mg(s) + O2(g) → 2MgO(s) | Synthesis | | 4. HNO3(aq) + NaOH(aq) → H2O(l) + NaNO3(aq) | Double Replacement | | 5. KBr(aq) + AgNO3(aq) → AgBr(s) + KNO3(aq) | Double Replacement | | 6. PbO2(s) → Pb(s) + O2(g) | Decomposition | | 7. S8(s) + 8O2(g) → 8SO2(g) | Synthesis | | 8. 2Al(s) + 3Cl2(g) → 2AlCl3(s) | Synthesis | | 9. 2AIN(s) → 2Al(s) + N2(g) | Decomposition | | 10. BaCl2(aq) + Na2SO4(aq) → BaSO4(s) + 2NaCl(aq) | Double Replacement | | 11. 2Cs(s) + Br2(g) → 2CsBr(s) | Synthesis | | 12. KOH(aq) + HCl(aq) → H2O(l) + KCl(aq) | Double Replacement | | 13. 2C2H2(g)+5O2(g) → 4CO2(g) + 2H2O(l) | Combustion | ## Word Equations Write the chemical equation for each of the following reactions and make sure they are balanced. 1. Solid mercury (II) oxide decomposes to produce liquid mercury metal and gaseous oxygen. 2HgO(s) → 2Hg(l) + O2(g) 2. Solid carbon reacts with gaseous oxygen to form gaseous carbon dioxide. C(s) + O2(g) → CO2(g) 3. Solid zinc is added to an aqueous solution containing dissolved hydrogen chloride to produce gaseous hydrogen that bubbles out of the solution and zinc chloride that remains dissolved in the water. Zn(s) + 2HCl(aq) → H2(g) + ZnCl2(aq) 4. Solid magnesium metal reacts with liquid water to form solid magnesium hydroxide and hydrogen gas. Mg(s) + 2H2O(l) → Mg(OH)2(s) + H2(g) 5. Solid ammonium dichromate decomposes to solid chromium (III) oxide, gaseous nitrogen and gaseous water. (NH4)2Cr2O7(s) → Cr2O3(s) + N2(g) + 4H2O(l) 6. Gaseous ammonia reacts with gaseous oxygen to form gaseous nitrogen monoxide and gaseous water. 2NH3(g) + 5/2O2(g) → 2NO(g) + 3H2O(g) 7. Liquid propane (C3H8) reacts with oxygen to produce gaseous carbon dioxide and gaseous water. C3H8(l) + 5O2(g) → 3CO2(g) + 4H2O(g) 8. Solid ammonium nitrite is heated and it produces nitrogen gas and water vapor. NH4NO2(s) → N2(g) + 2H2O(g) 9. Gaseous nitrogen monoxide decomposes to produce dinitrogen monoxide gas and nitrogen dioxide gas. 3NO(g) → N2O(g) + NO2(g) 10. Liquid nitric acid decomposes to reddish-brown nitrogen dioxide gas, liquid water, and oxygen gas. 2HNO3(l) → 2NO2(g) + H2O(l) + 1/2O2(g) # Gram Molecular Mass Worksheet ## Determine the gram molecular mass (the mass of one mole) of each compound below. 1. Potassium permaganate (KMnO4) * K: 39.1 g/mol * Mn: 54.9 g/mol * O: 16.0 g/mol x 4 = 64 g/mol * Total: 158 g/mol 2. Sodium sulfate (Na2SO4) * Na: 23 g/mol x 2 = 46 g/mol * S: 32.1 g/mol * O: 16 g/mol x 4 = 64 g/mol * Total: 142.1 g/mol 3. Calcium nitrate (Ca(NO3)2) * Ca: 40.1 g/mol * N: 14.0 g/mol x 2 = 28 g/mol * O: 16 g/mol x 6 = 96 g/mol * Total: 164.1 g/mol 4. Ammonium phosphate ((NH4)3PO4) * N: 14 g/mol x 3 = 42 g/mol * H: 1 g/mol x 12 = 12 g/mol * P: 31 g/mol * O: 16 g/mol x 4 = 64 g/mol * Total: 149 g/mol 5. Iron (II) oxide (FeO) * Fe: 55.8 g/mol * O: 16 g/mol * Total: 71.8 g/mol 6. Mercury (I) chromate (Hg2CrO4) * Hg: 200.6 g/mol x 2 = 401.2 g/mol * Cr: 52 g/mol * O: 16 g/mol x 4 = 64 g/mol * Total: 517.2 g/mol 7. Ammonium carbonate ((NH4)2CO3) * N: 14 g/mol x 2 = 28 g/mol * H: 1 g/mol x 8 = 8 g/mol * C: 12 g/mol * O: 16 g/mol x 3 = 48 g/mol * Total: 96 g/mol 8. Sulfuric acid (H2SO4) * H: 1 g/mol x 2 = 2 g/mol * S: 32.1 g/mol * O: 16 g/mol x 4 = 64 g/mol * Total: 98.1 g/mol 9. Hydrobromic acid (HBr) * H: 1 g/mol * Br: 79.9 g/mol * Total: 80.9 g/mol # Percent Composition Worksheet ## Find the percent compositions of all of the elements in the following compounds 1. CuBr2 * Cu: 63.5 g/mol * Br: 79.9 g/mol x 2 = 159.8 g/mol * Total: 223.3 g/mol * %Cu = (63.5 g/mol / 223.3 g/mol) x 100% = 28.44% * %Br = (159.8 g/mol / 223.3 g/mol) x 100% = 71.56% 2. NaOH * Na: 23.0 g/mol * O: 16 g/mol * H: 1 g/mol * Total: 40.0 g/mol * %Na = (23.0 g/mol / 40.0 g/mol) x 100% = 57.5 % * % O = (16 g/mol / 40.0 g/mol) x 100% = 40% * % H = (1 g/mol / 40.0 g/mol) x 100% = 2.5% 3. (NH4)2S * N: 14 g/mol x 2 = 28 g/mol * H: 1 g/mol x 8 = 8 g/mol * S: 32.1 g/mol * Total: 68.1 g/mol * %N = (28 g/mol / 68.1 g/mol) x 100% = 41.18 % * %H = (8 g/mol / 68.1 g/mol) x 100% = 11.76 % * %S = (32.1 g/mol / 68.1 g/mol) x 100% = 47.06 % 4. N2S2 * N: 14.0 g/mol x 2 = 28 g/mol * S: 32.1 g/mol x 2 = 64.2 g/mol * Total: 92.2 g/mol * % N = (28 g/mol / 92.2 g/mol) x 100% = 30.43 % * %S = (64.2 g/mol / 92.2 g/mol) x 100% = 69.57 % # Empirical Formulas The empirical formula of a compound expresses the simplest whole number ratio of elements in that compound. The empirical formula can be calculated form the percentage by mass for each element in the compound. ## Sample Problem The percentage composition by mass of a compound is 56.6% potassium, 8.7% carbon, and 34.7% oxygen. Find its empirical formula. **Solution** Assume that there are 100 grams of the compound then calculate the number of moles of atoms of each element in the sample. - 56.6 g K x (1 mole K / 39.1 g K) = 1.45 moles K - 8.7 g C x (1 mole C / 12.0 g C) = 0.73 mole C - 34.7 g O x (1 mole O / 16.0 g O) = 2.17 moles O Use the number of moles as subscripts for each element to express the ratio of atoms: K1.45C0.73O2.17 Convert these values to a simple whole number ratio by dividing each subscript by the smallest subscript. K 1.45 C 0.73 O 2.17 0.73 0.73 0.73 K2CO3 If the result of this step are half-integers, multiply by 2 to convert to whole numbers. In the same way, if the results are third-integers, multiply by 3. ## From percentage composition information in each of the following, calculate empirical formulas. 1. 69.6% barium, 6.1% carbon, 24.3% oxygen - Ba: 69.6 g x (1 mol Ba / 137.33 g/mol) = 0.507 mol - C: 6.1 g x (1 mol C / 12.01 g/mol) = 0.508 mol - O: 24.3 g x (1 mol O / 16.00 g/mol) = 1.52 mol Divide all elements by the smallest value (0.507 mol) to get the simplest whole number ratio. - Ba: 0.507 mol / 0.507 mol = 1 - C: 0.508 mol / 0.507 mol ≈ 1 - O: 1.52 mol / 0.507 mol ≈ 3 The empirical formula is **BaCO3**. 2. 40.5% zinc, 19.9% sulfur, 39.6% oxygen - Zn: 40.5 g x (1 mol Zn / 65.39 g/mol) = 0.619 mol - S: 19.9 g x (1 mol S / 32.07 g/mol) = 0.621 mol - O: 39.6 g x (1 mol O / 16.00 g/mol) = 2.48 mol Divide all elements by the smallest value (0.619 mol) to get the simplest whole number ratio. - Zn: 0.619 mol / 0.619 mol = 1 - S: 0.621 mol / 0.619 mol ≈ 1 - O: 2.48 mol / 0.619 mol ≈ 4 The empirical formula is **ZnSO4**. 3. 25.3% copper, 12.9% sulfur, 25.7% oxygen, 36.1% water (What is the charge of copper in this formula?) - Cu: 25.3 g x (1 mol Cu / 63.55 g/mol) = 0.398 mol - S: 12.9 g x (1 mol S / 32.07 g/mol) = 0.402 mol - O: 25.7 g x (1 mol O / 16.00 g/mol) = 1.60 mol - H2O: 36.1 g x (1 mol H2O / 18.02 g/mol) = 2.00 mol Divide all elements by the smallest value (0.398 mol) to get the simplest whole number ratio. - Cu: 0.398 mol / 0.398 mol = 1 - S: 0.402 mol / 0.398 mol ≈ 1 - O: 1.60 mol / 0.398 mol ≈ 4 - H2O: 2.00 mol / 0.398 mol ≈ 5 The empirical formula is **CuSO4 * 5H2O**. To figure out the charge of copper: - Sulfate (SO4 ) has a charge of -2 - There is one copper atom and one sulfate group in the empirical formula. - The overall charge must be neutral, so the copper atom must have a charge of +2. 4. 92% lead, 8% oxygen (What is the charge of lead in this formula?) - Pb: 92 g x (1 mol Pb / 207.2 g/mol) = 0.447 mol - O: 8 g x (1 mol O / 16.00 g/mol) = 0.500 mol Divide by the smallest value (0.447 mol): - Pb: 0.447 mol / 0.447 mol = 1 - O: 0.500 mol / 0.447 mol ≈ 1 The empirical formula is **PbO**. Oxygen has a charge of -2, and there is only one oxygen, so the lead must have a charge of +2 to balance the molecule.