A control group is the comparison group that helps to "make sure your experiment works." A control group is separated from the rest of the experiment and nothing happens to it kinda like a controlled variable. Controlled variables are the variables in a experiment that remains the same for example a temperature, time, type of products, etc..
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The total pressure of the system is equivalent to the sum of all the pressure of the individual gases. The total pressure of the flask is 2.37 atm.
<h3>What is total pressure?</h3>
According to Dalton's law, the total pressure of the system will be equivalent to the total of the pressures exerted by the individual gases present in the system.
The total pressure of gases is given as,

Given,
- The pressure of argon gas = 0.72 atm
- The pressure of oxygen = 1.65 atm
- Total pressure = P
Substituting values in the above equation:

Therefore, 2.37 atm is the total pressure of the flask.
Learn more about total pressure here:
brainly.com/question/11150092
Answer:
g NaCl = 424.623 g
Explanation:
<em>C</em> NaCl = 3.140 m = 3.140 mol NaCl / Kg solvent
∴ solvent: H2O
∴ mass H2O = 2.314 Kg
mol NaCl:
⇒ mol NaCl = (3.140 mol NaCl/Kg H2O)×(2.314 Kg H2O) = 7.266 mol NaCl
∴ mm NaCl = 58.44 g/mol
⇒ g NaCl = (7.266 mol NaCl)×(58.44 g/mol) = 424.623 g NaCl