I believe it's answer #3. Logically, at least.
You can test #1 through trial and error.
You can experiment #2 also through trial and error.
You cannot test #3 through trial and error, because that would be catastrophic.
You can test #4 through a survey and individual study and data collection.
Answer:
The acid must be a concentrated acid
Explanation:
Ethene is prepared in the laboratory by heating ethanol with excess concentrated tetraoxosulphate VI acid at 170°C . The reactionoccursc in two stages;
1) when the ethanol and sulphuric acid are mixed in a ratio of 1:2, ethyl hydrogentetraoxosulpate VI is formed
2) The compound formed in the first step is heated in the presence of excess concentrated sulphuric acid to give ethene and sulphuric acid.
The overall reaction can be perceived as the dehydration of ethanol. The gas produced (ethene) is usually passed through sodium hydroxide solution to remove any gaseous impurities present.
concentrated sulphuric acid is used in this process since it is a good dehydrating agent.
Potassium has 20 neutrons
Hope this helps
Explanation:The five major branches of chemistry are organic, inorganic, analytical, physical, and biochemistry.
...
Sub-branches of physical chemistry include:
Photochemistry — the study of the chemical changes caused by light.
Surface chemistry — the study of chemical reactions at surfaces of substances
