A physical change.
Physical change = can be reverted + doesn't change substance
Chemical = changes substance
Answer:
Lithium hydroxide is a base.
Carbon dioxide is the anhydride of the carbonic acid, H₂CO₃.
Therefore, the reaction awaited is a typical neutralization reaction with the formation of a salt and water.
2LiOH + CO₂ → Li₂CO₃ + H₂O
So, 2*20 = 40 moles of LiOH react with 20 moles of CO₂.
Molar Mass of LiOH = 23.95 g/mol
So, 40 * 23.95 = 958 g
Answer: Because Alkalis are bases that can dissolve in water, which can also neutralize acid.
Therefore option c , i.e. The substances in both test tubes are reactive only at high temperatures. is the only statement which is NOT supported by the student's observations.
<h3>What is the reaction between Magnesium and Hydrogen ?</h3>
Magnesium reacts with hydrochloric acid to produce hydrogen gas
Mg (s) + 2 HCl (aq) → MgCl₂ (aq) + H₂ (g)
In this reaction, the magnesium and acid are gradually used up , which can be seen in the test tube 2 .
A chemical reaction is taking place in Test tube 2 ,
Hydrogen gas is released in test tube 2 ,
Energy is released in the reaction involving hydrochloric acid and we can see in test tube 2 the reaction is going on
therefore option C i.e. The substances in both test tubes are reactive only at high temperatures. is the only statement which is NOT supported by the student's observation.
To know more about the chemical reaction between Magnesium and Hydrogen and this test.
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