Answer:
Stopwatches versus clocks. To improve reliability repeat the experiment multiple times according to an identical procedure. Record these steps so the experiment can be repeated at any time
Explanation:
D) Radioactive contamination
Answer:
See explanation
Explanation:
Crystals can be made from methanol by recrystallizing the plant extract from methanol.
The methanol/water system is heated rapidly using a hot plate and the plant extract dissolves in the heating solution until a clear solution is obtained.
The solution is now cooled rapidly. The interior of the flask used for the re crystallization may even by scratched to assist the quick formation of crystals. Large crystals of plant compounds may be obtained using this method. This process should be carried out in a fume hood because of the toxicity of methanol.
Answer:
C₃H₈(g) + 6 H₂O(g) ⇒ + 10 H₂(g) + 3 CO₂(g)
Explanation:
Propane can be turned into hydrogen by the two-step reforming process.
In the first step, propane and water react to form carbon monoxide and hydrogen. The balanced chemical equation is:
C₃H₈(g) + 3 H₂O(g) ⇒ 3 CO(g) + 7 H₂(g)
In the second step, carbon monoxide and water react to form hydrogen and carbon dioxide. The balanced chemical equation is:
CO(g) + H₂O(g) ⇒ H₂(g) + CO₂(g)
In order to get the net chemical equation for the overall process, we have to multiply the second step by 3 and add it to the first step. Then, we cancel what is repeated.
C₃H₈(g) + 3 H₂O(g) + 3 CO(g) + 3 H₂O(g) ⇒ 3 CO(g) + 7 H₂(g) + 3 H₂(g) + 3 CO₂(g)
C₃H₈(g) + 6 H₂O(g) ⇒ + 10 H₂(g) + 3 CO₂(g)
