Chemical Substitution Reactions And Energy Release ✓ Solved
Chemical Substitution Reactions and Energy Release
Chemical Substitution Reactions form the basis of many precipitation reactions. The task is to balance the reactions so that the same number of atoms of each type are found on both sides of the equation. You are to (a) CIRCLE the insoluble product, and (b) add the proper subscripts and coefficients so that the numbers of atoms balance.
Balancing Chemical Reactions
The first reactions to balance are:
- AgNO3 + NaCl → AgCl + NaNO3
- Fe(NO3)3 + NaOH → Fe(OH)3 + NaNO3
- Pb + NaCl → PbCl2 + NaNO3
- FeCl3 + Na2S → Fe + NaCl
- Cr(NO3)3 + KOH → Cr(OH)3 + KNO3
Observations on Solubility
It is common practice to note that most nitrates are soluble in water. This understanding aids in predicting the formation of precipitates when mixing different ionic solutions.
Exothermic Reactions
Exothermic reactions release energy, typically in the form of heat. This phenomenon is observable when water is produced in a reaction, as the temperature of the overall system tends to rise. A classic example involves the neutralization of acids and bases. To further explore exothermic reactions, we will assess the combustion of carbon compounds.
Burning Carbon Compounds
Balance the following reactions:
- C (coal) + O2 → CO2 (83.3 moles/kg)
- CH4 (methane) + O2 → CO2 + H2O (62.5 moles/kg)
- 2CH2 (ethane) + 7O2 → 4CO2 + 6H2O (33.3 moles/kg)
Summary and Discussion Questions
1. Historical context reveals that the Titanic and its sister ship were constructed to traverse the Atlantic Ocean, powered by engines using coal. Discuss the implications of energy source choices in maritime transportation.
2. Evaluate the efficiency of oil versus natural gas as heating sources under the assumption that both cost the same per ton. Consider factors like energy density and emissions in your discussion.
Acid-Base Chemistry
Identify and write the formulas for three strong acids (e.g., HCl, HNO3, H2SO4), one weak acid (e.g., CH3COOH), two strong bases (e.g., NaOH, KOH), and one weak base (e.g., NH3).
Standard Curve for Calcium Ion Measurement
In a standard curve setup to measure dissolved calcium ion in mine waters, fill in the blanks for standard solutions of CaCl2:
| Sample | Reading | Concentration (M) |
|---|---|---|
| Std1 | 0.60 | 0.012 |
| Std2 | 0.90 | 0.018 |
| Std3 | 1.20 | 0.024 |
| Std4 | 1.80 | 0.036 |
| Mine1 | 1.15 | - |
| Mine2 | 0.68 | - |
Conclusion
The study of chemical reactions, particularly substitution reactions and exothermic processes, presents opportunities to explore energy dynamics and the principles governing chemical interactions. Balancing equations, understanding solubility, and discussing energy resources are crucial components in chemistry that have pragmatic implications in various fields, including environmental science, engineering, and industrial applications.
References
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