Answer:
Mg + O2 ---> MgO
Explanation: V2O5 + CaS → CaO + V2S5. 5V2O5 + 5CaS → 10CaO + 5V2S5. 3V2O5 + 3CaS → 3CaO + 3V2S5.
Answer: a) 2H2 + O2 --> 2H2O
Explanation: 2 compounds are combining to form a new compound. The others have 2 substances as the end result and synthesis only produces one result (2H2O in this case)
In a way, all of the answers could be argued for (for example: in the first option: if the scientists' opinions are understood to be "informed understanding of the causes of events"), but one of the options is the best:
Scientific laws describe specific relationships in nature without offering
an explanation.
The reason why I think this is true is that many laws are phased too short and too concise to provide comprehensive explanations, instead they describe the relationships that must hold.
One of the options is pplain false:
Scientific laws explain why natural events occur. -"Scientific laws were theories that have been tested, proven, and adopted as laws." - since they are not adopted as laws.
The percent yield : 81.5%
<h3>Further explanation</h3>
Percent yield is the compare of the amount of product obtained from a reaction with the amount you calculated
General formula:
Percent yield = (Actual yield / theoretical yield )x 100%
An actual yield is the amount of product actually produced by the reaction. A theoretical yield is the amount of product that you calculate from the reaction equation according to the product and reactant coefficients
Reaction
2CO+O₂⇒2CO₂
mol CO(MW=28,01 g/mol)
mass CO₂ (theoretical)(MW=44,01 g/mol)
the percent yield :
Substance A is chlorophyll and Substance B is oxygen
