Chemical Reaction Lab
Lab #5
Chemical Reactions & Balancing Equations
Objectives Observe and classify several chemical and physical changes. Give evidence for the occurrence of a chemical reaction. Write a balanced equation for a chemical reaction. Identify a reaction as a combination, decomposition, replacement, or combustion reaction. Background Physical properties can be observed without changing the chemical composition of the substance. Common physical properties that can be measured without changing the chemical composition are melting point, boiling point, solubility and density. Taste and odor are usually considered to be physical properties although they depend on the physiology of the person making the observations. Physical changes do not cause a change …show more content…
in chemical composition, but only a change in appearance. When a substance simply changes from a solid to a liquid, liquid to a gas or viceversa (liquid water to solid water, for example) without a change in composition it is a change in state. This is a physical change. (The three physical states are: gas, liquid, and solid). Chemical properties describe the ability of a substance to react and change into another substance with a different chemical composition. The new substance would have new properties. Evidence that a chemical change is taking place includes: a) A color change b) A solid product, a precipitate is formed c) A gas is formed d) Energy such as heat, light or electricity is produced. Some Physical Changes Some Chemical Changes Change in state Formation of gas (bubbles) Change in size Formation of a solid (precipitates) Tearing Disappearance of a solid (dissolves) Breaking Change in color Grinding Heat is given off or absorbed Table 5.1. Comparison of Physical and Chemical Changes
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Balancing a Chemical Equation In a chemical reaction, atoms in the reactants are arranged to produce new combinations of atoms in the products. However, the total number of atoms of each element in the reactants is equal to the total number of atoms in the products. In an equation, the reactants are shown on the left and the products are on the right. An arrow between them indicates that a chemical reaction takes place. Reactants → Products To balance the number of atoms of each element on the left and right sides of the arrow, we write a number called a coefficient in front of the formula containing that particular element. Consider the balancing of the following unbalanced equation. The state of the substances as gas is shown as (g). N2(g) + H2(g) → NH3(g) N2(g) + H2(g) → 2NH3(g) N2(g) + 3H2(g) → 2NH3(g) Unbalanced equation A coefficient of 2 balances the N atoms A coefficient of 3 balances the H atoms. The equation is now balanced.
Types of Reactions There are many different chemical reactions, but most can be classified into the types of reactions shown below in Table 5.2 Type of Reaction Combination Description Elements or simple compounds form a more complex product Decomposition A reacting substance is split into simpler products Single Replacement One element takes the place of another element in a compound Double Replacement Elements in two compounds switch places Combustion Reactant and oxygen form an oxide product Table 5.2. Types of chemical reactions Example Equation Cu + S → CuS CaCO3 → CaO + CO2 Mg + 2HCl → MgCl2 + H2 AgNO3 + NaCl → AgCl + NaNO3 S + O2 → SO2
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Experimental Procedures
A. Observing and classifying types of changes of matter Perform the following tests at your lab bench. On your report sheet, record your observations and classify each experiment as a chemical or physical change. A.1 Ice Materials: Ice, beaker i. Obtain some ice from the reagent bench. Place it in a beaker. ii. Record your observations of what happens inside and outside the beaker. Indicate the type of change that occurred. A.2 Milk and Vinegar Materials: Milk, Vinegar i. Obtain 10 mL of milk in a beaker and mix with about 3 mL of vinegar. Stir with your glass stirring rod. Do not pour any solid down the sink. ii. Record your observations of what happens inside and outside the beaker. Indicate the type of change that occurred. A.3 Magnesium and Oxygen Materials: Magnesium ribbon(2-3 cm long), tongs, Bunsen burner i. Obtain a small strip (2-3 cm) of magnesium ribbon. Record its appearance. Using a pair of tongs to hold the end of the magnesium ribbon, ignite it using the flame of a Bunsen burner. As soon as the magnesium ribbon ignites, remove it from the flame. Shield your eyes as the ribbon burns. Record your observations of the reaction and the physical properties of the product. Use complete sentences to describe your observations. ii. Balance the equation given for the reaction. Use 1 as a coefficient when one unit of that substance is required. The letters in parentheses indicate the physical state of the reactant or product: (g) gas, (s) solid. Unbalanced equation: Mg(s) + O2(g)→ MgO(s) iii. Identify the type of reaction that has occurred. For this reaction, more than one reaction type may be used to classify the reaction. A.4 Zinc and Copper (II) Sulphate Materials: Two test tubes, test tube rack, 1 M CuSo4, Zn(s) i. Pour 3 mL of the 1 1 M CuSo4 solution into each of the two test tubes. Obtain a small piece of zinc metal. Describe the appearance of the CuSo4 solution in one of the test tubes. The CuSo4 solution in the other test tube is your reference for the initial solution color. Place the test tubes in the test tube rack and observe the color of the CuSo 4 solutions and the Zn piece again at 15 and 30 minutes. Pour the CuSO4 solutions into the
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ii.
iii.
sink followed by a large amount of water. Rinse the piece of Zn with water and place in the recycling container as directed by your instructor. Balance the equation given for the reaction. The symbol (aq) means aqueous (dissolved in water). Unbalanced equation: Zn(s) + CuSO4(aq) → Cu(s) + ZnSO4(aq) Identify the type of reaction that has occurred.
For all the experiments in parts A.5-A.7, use small quantities. For solids, use the amount of compound that will fit on the tip of a spatula or small scoop. Carefully pour small amounts of liquids into your beakers and other containers. Measure out 3 mL of water in a test tube. Use this volume as a reference level for each of the experiments. A.5 Metals and HCl Materials: Three test tubes, test tube rack, small pieces of Cu(s), Zn(s) and Mg(s) metal, 1 M HCl. i. Place 3 mL of 1 M HCl in each of the three test tubes. Describe the appearance of each metal. Carefully add a piece to the acid in each of the test tubes. Record any evidence of reaction such as bubbles of gas (H2). Carefully pour off the acid and follow with large quantities of water to dilute. Rinse the metal pieces with water, dry, and return to your instructor. Balance the equation given for each metal that gave a chemical reaction. If there was no reaction, cross out the products and write NR for no reaction. Unbalanced equations: a. Cu(s) + HCl(aq) → CuCl2(aq) +H2(g) b. Zn(s) + HCl(aq) → ZnCl2(aq) +H2(g) c. Mg(s) + HCl(aq) → MgCl2(aq) +H2(g) Identify the type of reaction that has occurred.
ii.
iii.
A.6 Reactions of Ionic Compounds Materials: Three test tubes, test tube rack, dropper bottle sets of 0.1M solutions: CaCl 2, Na3PO4, BaCl2, Na2SO4, FeCl3, KSCN For each of these reactions, two substances will be mixed together. Describe your observations of the reactants before you mix them and then describe the products of the reaction. Look for changes in color, the formation of a solid (solution turns cloudy), the dissolving of a solid, and/or the formation of a gas (bubbling). Balance the equations for the reactions. Dispose of the solutions properly. i. Place 20 drops each of 0.1 M CaCl2 and 0.1 M Na3PO4 into a test tube. Describe any changes that occur. Identify the type of reaction for each chemical reaction that occurred. Unbalanced equation: CaCl2 (aq) + Na3PO4 (aq) → Ca3PO4(s) + NaCl(aq)
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ii.
iii.
Place 20 drops each of 0.1 M BaCl2 and 0.1 M Na2SO4 into a test tube. Describe any changes that occur. Identify the type of reaction for each chemical reaction that occurred. Unbalanced equation: BaCl2 (aq) + Na2SO4 (aq) → BaSO4(s) + NaCl(aq) Place 20 drops each of 0.1 M FeCl3 and 0.1 M KSCN into a test tube. Describe any changes that occur. Identify the type of reaction for each chemical reaction that occurred. Unbalanced equation: FeCl3 (aq) + KSCN (aq) → Fe(SCN)3(aq) + KCl(aq)
A.7 Sodium Carbonate and HCl Materials: Three test tubes, test tube rack, 1 M HCl, Na2CO3(s), and matches or wood splints. i. ii. iii. Place about 3 mL of 1 M HCl in a test tube. Add a small amount of solid Na2CO3 (about the size of a pea) to the test tube. Record your observations. Identify the type of reaction for each chemical reaction that occurred. Unbalanced equation: Na2CO3 (s) + HCl (aq) → CO2(aq) + H2O(l) + NaCl(aq) Light a match or wood splint and insert the flame inside the neck of the test tube. What happens to the flame? Record your observations.
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Report Sheet –Lab
Date : Section: Instructor: Pre-Lab Study Questions 1.
What are physical properties? Name: Group Members:
2. Why is the freezing of water called a physical change?
3. What are chemical properties?
4. Why are burning candles and rusting nails examples of chemical changes?
5. What is included in a chemical equation?
6. How does a combination reaction differ from a decomposition reaction?
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A. Observing and classifying types of changes of matter A.1 Ice Observations: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Type of Change: ________________________________________________________________ A.2 Milk and Vinegar Observations: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Type of Change: ________________________________________________________________ A.3 Magnesium and Oxygen i. Initial appearance of
Mg
________________________________________________ ________________________________________________ Observations of the reaction ________________________________________________ ________________________________________________ Appearance of the product ________________________________________________ ________________________________________________ Balance: ____Mg(s) + ____O2(g)→ ____MgO(s) ________________________________________________ ________________________________________________
ii.
Type of reaction:
A.4 Zinc and Copper (II) Sulphate i. Initially Zn ______________________________________________________ CuSO4 ______________________________________________________ 15 min Zn ______________________________________________________
CuSO4 ______________________________________________________ 30 min Zn ______________________________________________________
CuSO4 ______________________________________________________
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ii. iii.
Balance:
____Zn(s) + ____CuSO4(aq) → ____Cu(s) + ____ZnSO4(aq) ________________________________________________ ________________________________________________
Type of reaction:
A.5 Metals and HCl i. Observations: Cu Initial Reaction Zn Initial Reaction Mg Initial Reaction ii. Balance:
______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________
____Cu(s) + ____HCl(aq) → ____CuCl2(aq) +____H2(g) ____Zn(s) + ____HCl(aq) → ____ZnCl2(aq) +____H2(g) ____Mg(s) + ____HCl(aq) → ____MgCl2(aq) +____H2(g) iii. Type of reaction: Cu Zn Mg ________________________________________________ ________________________________________________ ________________________________________________
A.6 Reactions of Ionic Compounds i. CaCl2 and Na3PO4 Observations: ____________________________________________________________ ____________________________________________________________ Type of reaction: __________________________________________________________ Balance: ____CaCl2 (aq) + ____Na3PO4 (aq) → ____Ca3PO4(s) + ____NaCl(aq) ii. BaCl2 and Na2SO4 Observations: ____________________________________________________________ ____________________________________________________________ Type of reaction: __________________________________________________________
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Balance: ____ BaCl2 (aq) + ____Na2SO4 (aq) → ____BaSO4(s) + ____NaCl(aq)
iii.
FeCl3 and KSCN Observations: ____________________________________________________________ ____________________________________________________________ Type of reaction: __________________________________________________________ Balance: ____ FeCl3 (aq) + ____KSCN (aq) → ____Fe(SCN)3(aq) + ____KCl(aq)
A.7 Sodium Carbonate and HCl i. Observations: ____________________________________________________________ ____________________________________________________________ ii. Type of reaction: __________________________________________________________ Balance: ____Na2CO3 (s) + ____HCl (aq) → ____CO2(aq) + ____H2O(l) + ____NaCl(aq) iii. Why did the flame of the burning match or splint go out?
Questions and Problems 1. Balance the following equations: a. ____Mg(s) + ____HCl(aq) → ____H2(g) + MgCl2(aq) b. ____Al(s) + ____O2(g) → ____Al2O3(s) c. ____Fe2O3(s) + ____H2O(l) → ____Fe(OH)3(s) d.____Ca(OH)2(aq) + ____HNO3(aq)→ ____Ca(NO3)2 (aq) + ____H2O(l) 2. Write an equation for the following reactions. Remember that gases of elements such as oxygen are diatomic (O2). Write the correct formulas of the reactants and products. Then correctly balance each equation. a) Potassium and oxygen gas react to form potassium oxide.
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b) Sodium and water react to form sodium hydroxide and hydrogen gas.
c) Iron and oxygen gas react to form iron Ill) oxide.
3. Classify each reaction as combination (C), decomposition (DC), single replacement (SR), or double replacement (DR). a) Ni + F2 → NiF2 _______________________ b) Fe2O3 + 3C → 2Fe + 3CO c) CaCO3 → CaO + CO2 d) H2SO4 + 2KOH → K2SO4 + 2H2O _______________________ _______________________ _______________________
4. Predict what products would be formed from the reaction of the following reactants: a) Zn + CuBr2 → __________ + __________ b) H2 + Cl2 → __________ + ___________ c) MgCO3 → __________ + ___________ d) KCl + AgNO3 → _________ + ___________
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Chemical Reactions & Balancing Equations
Objectives Observe and classify several chemical and physical changes. Give evidence for the occurrence of a chemical reaction. Write a balanced equation for a chemical reaction. Identify a reaction as a combination, decomposition, replacement, or combustion reaction. Background Physical properties can be observed without changing the chemical composition of the substance. Common physical properties that can be measured without changing the chemical composition are melting point, boiling point, solubility and density. Taste and odor are usually considered to be physical properties although they depend on the physiology of the person making the observations. Physical changes do not cause a change …show more content…
in chemical composition, but only a change in appearance. When a substance simply changes from a solid to a liquid, liquid to a gas or viceversa (liquid water to solid water, for example) without a change in composition it is a change in state. This is a physical change. (The three physical states are: gas, liquid, and solid). Chemical properties describe the ability of a substance to react and change into another substance with a different chemical composition. The new substance would have new properties. Evidence that a chemical change is taking place includes: a) A color change b) A solid product, a precipitate is formed c) A gas is formed d) Energy such as heat, light or electricity is produced. Some Physical Changes Some Chemical Changes Change in state Formation of gas (bubbles) Change in size Formation of a solid (precipitates) Tearing Disappearance of a solid (dissolves) Breaking Change in color Grinding Heat is given off or absorbed Table 5.1. Comparison of Physical and Chemical Changes
1
Balancing a Chemical Equation In a chemical reaction, atoms in the reactants are arranged to produce new combinations of atoms in the products. However, the total number of atoms of each element in the reactants is equal to the total number of atoms in the products. In an equation, the reactants are shown on the left and the products are on the right. An arrow between them indicates that a chemical reaction takes place. Reactants → Products To balance the number of atoms of each element on the left and right sides of the arrow, we write a number called a coefficient in front of the formula containing that particular element. Consider the balancing of the following unbalanced equation. The state of the substances as gas is shown as (g). N2(g) + H2(g) → NH3(g) N2(g) + H2(g) → 2NH3(g) N2(g) + 3H2(g) → 2NH3(g) Unbalanced equation A coefficient of 2 balances the N atoms A coefficient of 3 balances the H atoms. The equation is now balanced.
Types of Reactions There are many different chemical reactions, but most can be classified into the types of reactions shown below in Table 5.2 Type of Reaction Combination Description Elements or simple compounds form a more complex product Decomposition A reacting substance is split into simpler products Single Replacement One element takes the place of another element in a compound Double Replacement Elements in two compounds switch places Combustion Reactant and oxygen form an oxide product Table 5.2. Types of chemical reactions Example Equation Cu + S → CuS CaCO3 → CaO + CO2 Mg + 2HCl → MgCl2 + H2 AgNO3 + NaCl → AgCl + NaNO3 S + O2 → SO2
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Experimental Procedures
A. Observing and classifying types of changes of matter Perform the following tests at your lab bench. On your report sheet, record your observations and classify each experiment as a chemical or physical change. A.1 Ice Materials: Ice, beaker i. Obtain some ice from the reagent bench. Place it in a beaker. ii. Record your observations of what happens inside and outside the beaker. Indicate the type of change that occurred. A.2 Milk and Vinegar Materials: Milk, Vinegar i. Obtain 10 mL of milk in a beaker and mix with about 3 mL of vinegar. Stir with your glass stirring rod. Do not pour any solid down the sink. ii. Record your observations of what happens inside and outside the beaker. Indicate the type of change that occurred. A.3 Magnesium and Oxygen Materials: Magnesium ribbon(2-3 cm long), tongs, Bunsen burner i. Obtain a small strip (2-3 cm) of magnesium ribbon. Record its appearance. Using a pair of tongs to hold the end of the magnesium ribbon, ignite it using the flame of a Bunsen burner. As soon as the magnesium ribbon ignites, remove it from the flame. Shield your eyes as the ribbon burns. Record your observations of the reaction and the physical properties of the product. Use complete sentences to describe your observations. ii. Balance the equation given for the reaction. Use 1 as a coefficient when one unit of that substance is required. The letters in parentheses indicate the physical state of the reactant or product: (g) gas, (s) solid. Unbalanced equation: Mg(s) + O2(g)→ MgO(s) iii. Identify the type of reaction that has occurred. For this reaction, more than one reaction type may be used to classify the reaction. A.4 Zinc and Copper (II) Sulphate Materials: Two test tubes, test tube rack, 1 M CuSo4, Zn(s) i. Pour 3 mL of the 1 1 M CuSo4 solution into each of the two test tubes. Obtain a small piece of zinc metal. Describe the appearance of the CuSo4 solution in one of the test tubes. The CuSo4 solution in the other test tube is your reference for the initial solution color. Place the test tubes in the test tube rack and observe the color of the CuSo 4 solutions and the Zn piece again at 15 and 30 minutes. Pour the CuSO4 solutions into the
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ii.
iii.
sink followed by a large amount of water. Rinse the piece of Zn with water and place in the recycling container as directed by your instructor. Balance the equation given for the reaction. The symbol (aq) means aqueous (dissolved in water). Unbalanced equation: Zn(s) + CuSO4(aq) → Cu(s) + ZnSO4(aq) Identify the type of reaction that has occurred.
For all the experiments in parts A.5-A.7, use small quantities. For solids, use the amount of compound that will fit on the tip of a spatula or small scoop. Carefully pour small amounts of liquids into your beakers and other containers. Measure out 3 mL of water in a test tube. Use this volume as a reference level for each of the experiments. A.5 Metals and HCl Materials: Three test tubes, test tube rack, small pieces of Cu(s), Zn(s) and Mg(s) metal, 1 M HCl. i. Place 3 mL of 1 M HCl in each of the three test tubes. Describe the appearance of each metal. Carefully add a piece to the acid in each of the test tubes. Record any evidence of reaction such as bubbles of gas (H2). Carefully pour off the acid and follow with large quantities of water to dilute. Rinse the metal pieces with water, dry, and return to your instructor. Balance the equation given for each metal that gave a chemical reaction. If there was no reaction, cross out the products and write NR for no reaction. Unbalanced equations: a. Cu(s) + HCl(aq) → CuCl2(aq) +H2(g) b. Zn(s) + HCl(aq) → ZnCl2(aq) +H2(g) c. Mg(s) + HCl(aq) → MgCl2(aq) +H2(g) Identify the type of reaction that has occurred.
ii.
iii.
A.6 Reactions of Ionic Compounds Materials: Three test tubes, test tube rack, dropper bottle sets of 0.1M solutions: CaCl 2, Na3PO4, BaCl2, Na2SO4, FeCl3, KSCN For each of these reactions, two substances will be mixed together. Describe your observations of the reactants before you mix them and then describe the products of the reaction. Look for changes in color, the formation of a solid (solution turns cloudy), the dissolving of a solid, and/or the formation of a gas (bubbling). Balance the equations for the reactions. Dispose of the solutions properly. i. Place 20 drops each of 0.1 M CaCl2 and 0.1 M Na3PO4 into a test tube. Describe any changes that occur. Identify the type of reaction for each chemical reaction that occurred. Unbalanced equation: CaCl2 (aq) + Na3PO4 (aq) → Ca3PO4(s) + NaCl(aq)
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ii.
iii.
Place 20 drops each of 0.1 M BaCl2 and 0.1 M Na2SO4 into a test tube. Describe any changes that occur. Identify the type of reaction for each chemical reaction that occurred. Unbalanced equation: BaCl2 (aq) + Na2SO4 (aq) → BaSO4(s) + NaCl(aq) Place 20 drops each of 0.1 M FeCl3 and 0.1 M KSCN into a test tube. Describe any changes that occur. Identify the type of reaction for each chemical reaction that occurred. Unbalanced equation: FeCl3 (aq) + KSCN (aq) → Fe(SCN)3(aq) + KCl(aq)
A.7 Sodium Carbonate and HCl Materials: Three test tubes, test tube rack, 1 M HCl, Na2CO3(s), and matches or wood splints. i. ii. iii. Place about 3 mL of 1 M HCl in a test tube. Add a small amount of solid Na2CO3 (about the size of a pea) to the test tube. Record your observations. Identify the type of reaction for each chemical reaction that occurred. Unbalanced equation: Na2CO3 (s) + HCl (aq) → CO2(aq) + H2O(l) + NaCl(aq) Light a match or wood splint and insert the flame inside the neck of the test tube. What happens to the flame? Record your observations.
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Report Sheet –Lab
Date : Section: Instructor: Pre-Lab Study Questions 1.
What are physical properties? Name: Group Members:
2. Why is the freezing of water called a physical change?
3. What are chemical properties?
4. Why are burning candles and rusting nails examples of chemical changes?
5. What is included in a chemical equation?
6. How does a combination reaction differ from a decomposition reaction?
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A. Observing and classifying types of changes of matter A.1 Ice Observations: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Type of Change: ________________________________________________________________ A.2 Milk and Vinegar Observations: ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ ______________________________________________________________________________ Type of Change: ________________________________________________________________ A.3 Magnesium and Oxygen i. Initial appearance of
Mg
________________________________________________ ________________________________________________ Observations of the reaction ________________________________________________ ________________________________________________ Appearance of the product ________________________________________________ ________________________________________________ Balance: ____Mg(s) + ____O2(g)→ ____MgO(s) ________________________________________________ ________________________________________________
ii.
Type of reaction:
A.4 Zinc and Copper (II) Sulphate i. Initially Zn ______________________________________________________ CuSO4 ______________________________________________________ 15 min Zn ______________________________________________________
CuSO4 ______________________________________________________ 30 min Zn ______________________________________________________
CuSO4 ______________________________________________________
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ii. iii.
Balance:
____Zn(s) + ____CuSO4(aq) → ____Cu(s) + ____ZnSO4(aq) ________________________________________________ ________________________________________________
Type of reaction:
A.5 Metals and HCl i. Observations: Cu Initial Reaction Zn Initial Reaction Mg Initial Reaction ii. Balance:
______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________ ______________________________________________________
____Cu(s) + ____HCl(aq) → ____CuCl2(aq) +____H2(g) ____Zn(s) + ____HCl(aq) → ____ZnCl2(aq) +____H2(g) ____Mg(s) + ____HCl(aq) → ____MgCl2(aq) +____H2(g) iii. Type of reaction: Cu Zn Mg ________________________________________________ ________________________________________________ ________________________________________________
A.6 Reactions of Ionic Compounds i. CaCl2 and Na3PO4 Observations: ____________________________________________________________ ____________________________________________________________ Type of reaction: __________________________________________________________ Balance: ____CaCl2 (aq) + ____Na3PO4 (aq) → ____Ca3PO4(s) + ____NaCl(aq) ii. BaCl2 and Na2SO4 Observations: ____________________________________________________________ ____________________________________________________________ Type of reaction: __________________________________________________________
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Balance: ____ BaCl2 (aq) + ____Na2SO4 (aq) → ____BaSO4(s) + ____NaCl(aq)
iii.
FeCl3 and KSCN Observations: ____________________________________________________________ ____________________________________________________________ Type of reaction: __________________________________________________________ Balance: ____ FeCl3 (aq) + ____KSCN (aq) → ____Fe(SCN)3(aq) + ____KCl(aq)
A.7 Sodium Carbonate and HCl i. Observations: ____________________________________________________________ ____________________________________________________________ ii. Type of reaction: __________________________________________________________ Balance: ____Na2CO3 (s) + ____HCl (aq) → ____CO2(aq) + ____H2O(l) + ____NaCl(aq) iii. Why did the flame of the burning match or splint go out?
Questions and Problems 1. Balance the following equations: a. ____Mg(s) + ____HCl(aq) → ____H2(g) + MgCl2(aq) b. ____Al(s) + ____O2(g) → ____Al2O3(s) c. ____Fe2O3(s) + ____H2O(l) → ____Fe(OH)3(s) d.____Ca(OH)2(aq) + ____HNO3(aq)→ ____Ca(NO3)2 (aq) + ____H2O(l) 2. Write an equation for the following reactions. Remember that gases of elements such as oxygen are diatomic (O2). Write the correct formulas of the reactants and products. Then correctly balance each equation. a) Potassium and oxygen gas react to form potassium oxide.
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b) Sodium and water react to form sodium hydroxide and hydrogen gas.
c) Iron and oxygen gas react to form iron Ill) oxide.
3. Classify each reaction as combination (C), decomposition (DC), single replacement (SR), or double replacement (DR). a) Ni + F2 → NiF2 _______________________ b) Fe2O3 + 3C → 2Fe + 3CO c) CaCO3 → CaO + CO2 d) H2SO4 + 2KOH → K2SO4 + 2H2O _______________________ _______________________ _______________________
4. Predict what products would be formed from the reaction of the following reactants: a) Zn + CuBr2 → __________ + __________ b) H2 + Cl2 → __________ + ___________ c) MgCO3 → __________ + ___________ d) KCl + AgNO3 → _________ + ___________
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