<u>Answer:</u> The correct answer is Option 5.
<u>Explanation:</u>
- To calculate the molarity of the solution after mixing 2 solutions, we use the equation:

where,
are the n-factor, molarity and volume of the NaOH.
are the n-factor, molarity and volume of the 
We are given:
Putting all the values in above equation, we get:

- To calculate the molarity of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base.
We are given:

Putting values in above equation, we get:

Hence, the correct answer is Option 5.
The answer is lower. when there’s a lower temperature the molecules will be moving at a lower speed. a lower speed means less thermal energy.
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.
brainly.com/question/19062002
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The two oxygen atoms share two pairs of electrons, so two covalent bonds hold the oxygen molecule together
Answer:
B: Adding water, then adding solute
Explanation:
This is because, say you have a solution with a certain concentration.
If you add more water, it will become more diluted (less concentrated)
If you add more solute, it will become more concentrated.
Therefore if you add water and solute, it could cancel out, and the concentration would remain the same.
Hope this helps! Let me know if you have any questions/ would like anything further explained :)