Experiment: A burning candle was placed in a closed bell jar.Observation: The flame extinguished after some time and condensation appeared inside the jar.Question: What conclusion can be made?
Correct answer: B. Oxygen is necessary for combustion and is used up.
- A. Carbon dioxide supports combustion.
- B. Oxygen is necessary for combustion and is used up.
- C. Water is released from the wax only due to heat.
- D. Air becomes flammable over time.
Explanation
The correct answer is B: Oxygen is necessary for combustion and is used up. The observation of the flame extinguishing and condensation appearing inside the closed bell jar indicates that oxygen, essential for combustion, was consumed by the burning candle. Option A is incorrect as carbon dioxide does not support combustion. Option C is incorrect as the condensation is not solely due to the release of water from the wax. Option D is incorrect as air does not become flammable over time.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Scientific Reasoning
Scientific reasoning evaluates hypotheses through observations, variables, controls, measurements and experimental results. Questions involve identifying independent and dependent variables, recognising a fair test, interpreting tables or graphs, distinguishing evidence from opinion, and deciding whether data supports, rejects or leaves a hypothesis unresolved.
Practise Scientific Reasoning
334 free Scientific Reasoning MCQs from Analytical and Logical Reasoning, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Analytical and Logical Reasoning questions like this
Analytical and Logical Reasoning is on 27 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Scientific Reasoning questions
Experiment: Aluminium foil was added to a solution of dilute sulfuric acid.Observation: Bubbles of gas formed and the foil slowly dissolved.Question: Which gas is being evolved?
Experiment: A beaker containing water and ice was kept at room temperature and its temperature was recorded every minute.Observation: The temperature remained at 0°C until all ice melted.Question: What does this show?
Experiment: A mixture of iron filings and sulfur was heated strongly in a test tube.Observation: A black solid formed that was attracted by a magnet only slightly.Question: What does this demonstrate?
Experiment: Dilute nitric acid was added to powdered iron in a beaker.Observation: A brown gas was released, and the solution turned light green.Question: What does this indicate?
Experiment: Carbon dioxide was passed through limewater and then in excess.Observation: Limewater turned milky, then became clear again.Question: What does this show?
Experiment: Two colorless liquids (ethanol and water) were mixed and the temperature increased.Observation: The beaker felt warm to touch.Question: What kind of process occurred?