Purpose: Two observe two different single displacement reactions.
Hypothesis:
When zinc is added to copper (II) sulfate, a single displacement reaction will take place, creating a solid, copper, and zinc sulfate.
When zinc is added to hydrochloric acid, hydrogen gas will be released a solid, zinc chloride, will be formed.
Materials:
- Hydrochloric acid
- Zinc
- Copper (II) sulfate
- Test tubes (4)
- Graduated cylinder
- Watch glasses
Procedure:
Part A
- Pour 2ml of copper (II) sulfate in a test tube. Record the physical properties of the solution.
- Record the physical properties of zinc.
- Add the zinc to the solution.
- Observe and record the reaction.
- After 30 minutes, record the new colour of the solution and the physical properties of zinc.
Part B
- Pour 2 ml of hydrochloric acid into the test tube. Record the physical properties of the solution.
- After recording the physical properties of zinc, add it to the solution.
- Observe and record the reaction.
Questions:
- What indicated that a chemical reaction took place when zinc and copper (II) sulfate were combined?
- Observations such as zinc turning black soon after being placed in water indicated that a chemical reaction had taken place.
- What indicated that a chemical reaction took place when zinc and hydrochloric acid were combined?
- When zinc and hydrochloric acid were combined, zinc turned black and hydrogen bubbles were released. This indicated that a chemical reaction had taken place.
- Name the reactants in Part A:
- copper (I) sulfate + zinc
- Name the products in Part A:
- zinc sulfate + copper
- Name the reactants in Part B:
- hydrochloric acid + zinc
- Name the products in Part B:
- hydrogen + zinc chloride
- What new elements were formed in Part A? In Part B?
- Part A – copper
Part B – hydrogen
- What new compounds were formed in Part A? In Part B?
- Part A – zinc sulfate
Part B – zinc chloride
- Complete and balance the chemical equations below that represent the chemical reactions, which took place:
| Zn | + | CuSO4 | => | Cu | + | ZnSO4 |
| Zn | + | 2HCl | => | H2 | + | ZnCl2 |
- What is a single replacement reaction?
- A single displacement reaction occurs when an element reacts with a compound in a chemical reaction. During the reaction, the element replaces the anion or the cation in the compound.
- Complete and balance the following single replacement reactions:
| A. | Fe II | + | CuSO4 | => | FeSO4 | + | Cu |
| B. | Cu I | + | AgNO3 | => | CuNO3 | + | Ag |
| C. | Zn | + | AgNO3 | => | Zn(NO3)2 | + | Ag |
| D. | Cu II | + | HgCl2 | => | CuCl2 | + | Hg |
| E. | K | + | NaCl | => | KCl | + | Na |
| F. | 2HOH | + | Ca | => | Ca(OH)2 | + | H2 |
| G. | MgBr2 | + | Cl2 | => | MgCl2 | + | Br2 |
| H. | Fe2O3 | + | 2Al | => | Al2O3 | + | 2Fe |
| I. | 3H2SO4 | + | 2Al | => | Al2(SO4)3 | + | 3H2 |
| J. | 2KI | + | Cl2 | => | 2KCl | + | I2 |
- Write the names of the reactants and products for the equations listed in question number 12:
| Reactants | Products | |||
| A. | iron | copper (I) sulfate | iron (II) sulfate | copper |
| B. | copper | silver nitrate | copper (I) nitrate | silver |
| C. | zinc | silver nitrate | zinc nitrate | silver |
| D. | copper | mercury (II) chloride | copper (II) chloride | mercury |
| E. | potassium | sodium chloride | potassium chloride | sodium |
| F. | water | calcium | calcium hydroxide | hydrogen gas |
| G. | magnesium bromide | chlorine gas | magnesium chloride | bromine gas |
| H. | iron (III) oxide | aluminum | aluminum oxide | iron |
| I. | sulfuric acid | aluminum | aluminum sulfate | hydrogen gas |
| J. | potassium iodide | chlorine gas | potassium chloride | iodine gas |
Theory:
In order for a single displacement reaction to occur, an element and a compound need to be present. When the element and the compound are mixed, the element replaces the anion or the cation in the compound. During the experiment, when zinc was added to copper (II) sulfate, zinc reacted with copper (II) sulfate to create zinc sulfate and copper. In this reaction, the element, zinc, replaced copper in the compound copper sulfate, thus creating zinc sulfate. Similarly, when hydrochloric acid reacted with zinc, zinc replaced hydrogen, creating zinc chloride and hydrogen gas.
Observations:
| Reactants | Colour | State |
| Part A: | ||
| Copper (II) sulfate | Blue | Liquid |
| Zinc | Silver, metal | Solid |
| Part B: | ||
| Hydrochloric acid | Clear | Liquid |
| Zinc | Silver, metal | Solid |
Fig 1. Physical properties of the reactants
| Products | Colour | State |
| Part A: | ||
| Zinc sulfate | Light blue | Liquid |
| Copper | Red-brown | Solid |
| Part B: | ||
| Zinc chloride | Black | Solid |
| Hydrogen gas | Clear | Gas |
Fig 2. Physical properties of the reactants
Conclusion:
When zinc was added to copper (II) sulfate, it reacted to create a solution, zinc sulfate, and a solid, copper. When zinc was added to hydrochloric acid, hydrogen gas and zinc sulfate were produced, therefore the hypothesis was supported.
Sources of error:
During the experiment, several factors could have possibly affected the results of the observations. One of these factors includes the contamination of the test tubes. After washing the test tubes, water or other acids could have been left behind, affecting the results of the upcoming experiments. Another factor that would have affected the results would have been the inaccurate measurement of the solution. Even if the solution differed by few drops, it could have affected the results.
Works cited:
Clancy, Christina et al. McGraw-Hill Ryerson Chemistry 11. Toronto: McGraw-Hill Ryerson, 2011. Print
