Placing solid ammonium nitrate, NH4NO3, in a container of water causes an endothermic reaction. The result is ammonium hydroxide, NH4OH, and nitric acid, HNO3. Which diagram shows the correct equation for the reaction?
- A. NH4OH + HNO3 → NH4NO3 + H2O + energy
- B. NH4NO3 + H2O + energy → NH4OH + HNO3
- C. NH4NO3 + H2O → NH4OH + HNO3 + energy
- D. NH4OH + HNO3 + energy → NH4NO3 + H2O
Correct Answer & Rationale
Correct Answer: B
The reaction between solid ammonium nitrate and water is endothermic, meaning it absorbs energy. Thus, the equation must reflect the consumption of energy during the process. Option B correctly shows that ammonium nitrate (NH4NO3) and water react to form ammonium hydroxide (NH4OH) and nitric acid (HNO3), while requiring energy input. Option A incorrectly suggests energy is released, which contradicts the endothermic nature of the reaction. Option C implies that energy is produced, which is also incorrect. Option D similarly misrepresents the reaction by suggesting energy is released, aligning with an exothermic process rather than the observed endothermic reaction.
The reaction between solid ammonium nitrate and water is endothermic, meaning it absorbs energy. Thus, the equation must reflect the consumption of energy during the process. Option B correctly shows that ammonium nitrate (NH4NO3) and water react to form ammonium hydroxide (NH4OH) and nitric acid (HNO3), while requiring energy input. Option A incorrectly suggests energy is released, which contradicts the endothermic nature of the reaction. Option C implies that energy is produced, which is also incorrect. Option D similarly misrepresents the reaction by suggesting energy is released, aligning with an exothermic process rather than the observed endothermic reaction.
Other Related Questions
A 60W light bulb used .48 kilowatt hours of electricity. How long was the light bulb on?
- A. 0.48 hours
- B. 28.8 hours
- C. 0.125 hours
- D. 8 hours
Correct Answer & Rationale
Correct Answer: D
To determine how long the 60W light bulb was on, we first convert the energy used from kilowatt hours to watt hours: 0.48 kWh equals 480 watt hours. Using the formula: time (hours) = energy (watt hours) / power (watts), we calculate: 480 watt hours / 60 watts = 8 hours. Option A (0.48 hours) underestimates the time significantly. Option B (28.8 hours) incorrectly suggests the bulb was on much longer than the energy consumed allows. Option C (0.125 hours) miscalculates by assuming a much higher power consumption. Only option D accurately reflects the time the bulb was on based on the energy used.
To determine how long the 60W light bulb was on, we first convert the energy used from kilowatt hours to watt hours: 0.48 kWh equals 480 watt hours. Using the formula: time (hours) = energy (watt hours) / power (watts), we calculate: 480 watt hours / 60 watts = 8 hours. Option A (0.48 hours) underestimates the time significantly. Option B (28.8 hours) incorrectly suggests the bulb was on much longer than the energy consumed allows. Option C (0.125 hours) miscalculates by assuming a much higher power consumption. Only option D accurately reflects the time the bulb was on based on the energy used.
The chemical composition and energy density of four fuels are shown in the table. Ethane, which has a chemical composition of C2H6, is also a fuel. What is the predicted energy density of ethane?
- A. 45 MJ/kg
- B. 42 MJ/kg
- C. 52 MJ/kg
- D. 48 MJ/kg
Correct Answer & Rationale
Correct Answer: C
To determine the predicted energy density of ethane (C2H6), one can analyze its molecular structure and compare it to the energy densities of similar hydrocarbons listed in the table. Ethane, being an alkane, typically has a higher energy density due to its saturated carbon-hydrogen bonds. Option A (45 MJ/kg) is lower than expected for alkanes of similar size. Option B (42 MJ/kg) underestimates the energy density, as it does not align with the general trend for hydrocarbons. Option D (48 MJ/kg) is closer but still below the typical range for ethane. Thus, option C (52 MJ/kg) aligns with the expected energy density for ethane, reflecting its molecular composition and energy potential.
To determine the predicted energy density of ethane (C2H6), one can analyze its molecular structure and compare it to the energy densities of similar hydrocarbons listed in the table. Ethane, being an alkane, typically has a higher energy density due to its saturated carbon-hydrogen bonds. Option A (45 MJ/kg) is lower than expected for alkanes of similar size. Option B (42 MJ/kg) underestimates the energy density, as it does not align with the general trend for hydrocarbons. Option D (48 MJ/kg) is closer but still below the typical range for ethane. Thus, option C (52 MJ/kg) aligns with the expected energy density for ethane, reflecting its molecular composition and energy potential.
best explains the ammonia deposits found in ice core samples from the time of the Tunguska Event. The evidence that best supports the validity of this hypothesis is the-
- A. Hypothesis 2
- B. heat produced by fast-moving objects in the atmosphere
- C. Hypothesis 1
- D. match between measured and predicted amounts of ammonia
Correct Answer & Rationale
Correct Answer: A,D
The ammonia deposits found in ice core samples from the time of the Tunguska Event suggest a significant environmental impact. Hypothesis 2 (Option A) likely proposes a link between the event and the ammonia presence, making it relevant for explaining the deposits. Option B, which discusses heat from fast-moving objects, does not directly address ammonia production or accumulation. Hypothesis 1 (Option C) may not provide sufficient evidence or detail to support the ammonia findings. Option D highlights the alignment between measured and predicted ammonia levels, reinforcing the validity of Hypothesis 2 as it connects empirical data with theoretical expectations.
The ammonia deposits found in ice core samples from the time of the Tunguska Event suggest a significant environmental impact. Hypothesis 2 (Option A) likely proposes a link between the event and the ammonia presence, making it relevant for explaining the deposits. Option B, which discusses heat from fast-moving objects, does not directly address ammonia production or accumulation. Hypothesis 1 (Option C) may not provide sufficient evidence or detail to support the ammonia findings. Option D highlights the alignment between measured and predicted ammonia levels, reinforcing the validity of Hypothesis 2 as it connects empirical data with theoretical expectations.
Scientists can indirectly observe temperatures and insolation (the Intensity or direct solar radiation) in the distant past by measuring oxygen isotope ratios in ice cores collected from polar ice. The graph presents data for the period from what ta200.000 years ago. What time period in the graph shows the greatest correlation between Milankovitch cycles and climate?
- A. 140,000-160,000 years ago
- B. 120,000-140,000 years ago
- C. 100,000-120,000 years ago
- D. 160,000-180,000 years ago
Correct Answer & Rationale
Correct Answer: C
The time period from 100,000 to 120,000 years ago exhibits the greatest correlation between Milankovitch cycles and climate, as evidenced by significant fluctuations in temperature and insolation reflected in the oxygen isotope ratios. This interval aligns closely with the timing of glacial and interglacial periods influenced by Earth's orbital changes. Options A and B show notable climate changes, but they do not align as strongly with Milankovitch cycles, indicating less correlation. Option D, while part of the broader glacial cycle, reveals less pronounced temperature shifts, making it less relevant to the question of correlation.
The time period from 100,000 to 120,000 years ago exhibits the greatest correlation between Milankovitch cycles and climate, as evidenced by significant fluctuations in temperature and insolation reflected in the oxygen isotope ratios. This interval aligns closely with the timing of glacial and interglacial periods influenced by Earth's orbital changes. Options A and B show notable climate changes, but they do not align as strongly with Milankovitch cycles, indicating less correlation. Option D, while part of the broader glacial cycle, reveals less pronounced temperature shifts, making it less relevant to the question of correlation.