Answer : The pressure of gas will be, 3.918 atm and the combined gas law is used for this problem.
Solution :
Combined gas law is the combination of Boyle's law, Charles's law and Gay-Lussac's law.
The combined gas equation is,

where,
= initial pressure of gas = 3 atm
= final pressure of gas = ?
= initial volume of gas = 1.40 L
= final volume of gas = 0.950 L
= initial temperature of gas = 
= final temperature of gas = 
Now put all the given values in the above equation, we get the final pressure of gas.


Therefore, the pressure of gas will be, 3.918 atm and the combined gas law is used for this problem.
Answer:
In the final solution, the concentration of sucrose is 0.126 M
Explanation:
Hi there!
The number of moles of solute in the volume taken from the more concentrated solution will be equal to the number of moles of solute in the diluted solution. Then, the concentration of the first solution can be calculated using the following equation:
Ci · Vi = Cf · Vf
Where:
Ci = concentration of the original solution
Vi = volume of the solution taken to prepare the more diluted solution.
Cf = concentration of the more diluted solution.
Vf = volume of the more diluted solution.
For the first dillution:
26.6 ml · 2.50 M = 50.0 ml · Cf
Cf = 26.6 ml · 2.50 M / 50.0 ml
Cf = 1.33 M
For the second dilution:
16.0 ml · 1.33 M = 45.0 ml · Cf
Cf = 16.0 ml · 1.33 M / 45.0 ml
Cf = 0.473 M
For the third dilution:
20.0 ml · 0.473 M = 75.0 ml · Cf
Cf = 20.0 ml · 0.473 M / 75.0 ml
Cf = 0.126 M
In the final solution, the concentration of sucrose is 0.126 M
Answer:
1) magnesium chloride
2) b) The copper is getting oxidized from Cu+ to Cu2+ and turns blue.
Explanation:
The work published by David N. Frick, Sukalyani Banik, and Ryan S. Rypma in J Mol Biol. 2007 Jan 26; 365(4): 1017–1032 clearly shows that divalent metal ions of group 2 such as Mg^2+ play an important role in ATP hydrolysis. Addition of EDTA decreased the rate of hydrolysis of ATP (due to sequestration of the divalent ion of group 2) indicating an active participation of divalent ions in the process.
2) The copper I ion is colourless because it is a d^10 specie. However, when it is oxidized to Cu^2+, a blue colour appears in the solution.