Please check my answers
For each of the 7 reactions in this experiment, write a balanced equation and classify it as a synthesis, decomposition, single replacemnt, neutralization, or double replacement reaction. Reaction 1
1)Adjust a burner flae to high heat 2)using crucible tongs, hold a 6cm length of bare copper wire in the hottest part of the flame for a few minutes.
Reaction 2
1)clean an iron nail with a piece of steel wool so that the surface of the nail is shiny 2)plave the nail in a test tube and add copper(II)sulfate solution so that one half of the nail is covered 3)After approximately 15min, remove the nail and note any changes in both the nail and the solution. Reaction 3
1)Put some solid copper(II)sulfate pentahydrate in a test tube so that it is one third full 2)Using a test tube clamp, hold the test tube and contents at an angle away from yourself and your classmates. Heat the test tube, moving it back and forth gently over a burner flame 3)continue heating until no further change is observed (save contents for reaction 4)
Reaction 4
1)allow the test tube and contents from reaction 3 to cool 2)use a medicine dropper to add 2 to 3 drops of water to the test tube
Reaction 5
1)fill a test tube one quarter full with calcium chloride solution. Fill a second test tube one quarter full with sodium carbonate solution. 2)pour the calcium chloride solution into the test tube containing sodium carbonate solution.
Reaction 6
1)place a piece of mossy zinc in a test tube 2)add hydrochloric acid solution to the test tube until the mossy zinc is completely covered.
Reaction 7
1)Half fill a test with hydrogen peroxide solution 2)add a small amount of maganese (IV) oxide. (notes Maganese(IV)oxide acts as a catalyst in this reaction) 3)Test the gas evolved by placing a glowing (not burning) splint into the mouth of the test tube. 4)Before you leave the laboratory, wash your hands thoroughly with soap and waterl; use a fingernail brush to clean under ur nails.
My answers :
1) 2Cu(s) + O₂(g) => 2CuO(s) synthesis
2) Fe(s) + CuSO₄(aq) => FeSO₄(aq) + Cu(s) single-replacement
3) CuSO₄·5H₂O(s) => CuSO₄(s) + 5H₂O(g) decomposition
4) CuSO₄(s) + 5H₂O(l) => CuSO₄·5H₂O(s) synthesis
5) CaCl₂(aq) + Na₂CO₃(aq) => CaCO₃(aq) + 2NaCl(aq) double-replacement
6) Zn(s) + 2HCl(aq) => ZnCl₂(aq) + H₂(g) single-replacement
7) 2H₂O₂(aq) => 2H₂O(l) + O₂(g)
Decomposition
Are these correct ? Thanks :)
1. Synthesis is right. You should note the color of the oxide produced. A red or yellow color denotes the formaton of Cu2O. A black color is CuO. Generally if Cu is heated in air it forms both.
4. There is nothing wrong with what you wrote; however, I wanted you to know that sometimes ALL of that water doesn't go back at one time; i.e., some of the intermediates may form.
All look good to me.
Your answers are mostly correct, but there are a couple of corrections needed.
1) The balanced equation is correct, and it is a synthesis reaction.
2) The balanced equation should be: Fe(s) + CuSO4(aq) -> FeSO4(aq) + Cu(s). It is indeed a single-replacement reaction.
3) The balanced equation is correct, and it is a decomposition reaction.
4) The balanced equation should be: CuSO4(s) + 5H2O(l) -> CuSO4*5H2O(s). It is also a synthesis reaction.
5) The balanced equation is correct, and it is a double-replacement reaction.
6) The balanced equation is correct, and it is a single-replacement reaction.
7) The balanced equation is correct, and it is a decomposition reaction.
Overall, your answers are mostly correct. Just make the corrections listed above. Well done!
Your answers are correct! Well done.
Here is an explanation of how to determine the balanced equations and classify the reactions for each part:
Reaction 1: This is a synthesis reaction because copper wire (Cu) is reacting with oxygen (O₂) to form copper(II) oxide (CuO). The balanced equation is: 2Cu(s) + O₂(g) → 2CuO(s)
Reaction 2: This is a single replacement reaction since iron (Fe) is displacing copper (Cu) in copper(II) sulfate (CuSO₄). The balanced equation is: Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s)
Reaction 3: This is a decomposition reaction because solid copper(II) sulfate pentahydrate (CuSO₄·5H₂O) is being heated to produce copper(II) sulfate (CuSO₄) and water (H₂O). The balanced equation is: CuSO₄·5H₂O(s) → CuSO₄(s) + 5H₂O(g)
Reaction 4: When water (H₂O) is added to copper(II) sulfate (CuSO₄), it forms hydrated copper(II) sulfate (CuSO₄·5H₂O), which is the same substance obtained in reaction 3. The balanced equation is: CuSO₄(s) + 5H₂O(l) → CuSO₄·5H₂O(s)
Reaction 5: This is a double replacement reaction as calcium chloride (CaCl₂) reacts with sodium carbonate (Na₂CO₃) to form calcium carbonate (CaCO₃) and sodium chloride (NaCl). The balanced equation is: CaCl₂(aq) + Na₂CO₃(aq) → CaCO₃(aq) + 2NaCl(aq)
Reaction 6: In this single replacement reaction, zinc (Zn) reacts with hydrochloric acid (HCl) to form zinc chloride (ZnCl₂) and hydrogen gas (H₂). The balanced equation is: Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)
Reaction 7: This is a decomposition reaction as hydrogen peroxide (H₂O₂) breaks down into water (H₂O) and oxygen gas (O₂). The balanced equation is: 2H₂O₂(aq) → 2H₂O(l) + O₂(g)
Once again, your answers are correct!