<h2>Answer : Option C) Joseph is observing the color of the reaction mixture to see whether proteins are present in the given solution.</h2><h3>Explanation :</h3>
An example of qualitative observation is the one where one uses the five senses to identify the changes in the reaction.
Here, when Joseph is studying a reaction mixture he is trying to observe a color change which will confirm that there is proteins present in the reaction mixture or not If there is a color change observed then it will confirm the presence of proteins.
Usually qualitative observations are those which can be easily predicted by using five senses.
Answer:
1) Increasing temperature
2) Stirring
3) Increasing surface area of salt by grinding it
Answer: The pressure of the He is 2.97 atm
Explanation:
According to Dalton's law, the total pressure is the sum of individual pressures.
Given : 
=total pressure of gases = 6.50 atm
= partial pressure of Nitrogen = 1.23 atm
= partial pressure of oxygen = 2.3 atm
= partial pressure of Helium = ?
putting in the values we get:
The pressure of the He is 2.97 atm
Hello!
When something is a liquid then turns to a gas, this is known as evaporating so we would call it the heat of evaporation or also known as latent heat. Just remember liquid to gas is vapor!
I hope this helped!
I am, yours most sincerely,
SuperHelperThingy
