1) D = 13.6 g / mL
2)ethyl alcohol weighs 158g
3)ρ
_copper = 8.9 g 
Explanation:
1)
D = m / V
=306.0 g / 22.5 mL
D= 13.6 g / mL
2)
density = mass / volume
mass = density × volume
=0.789g /ml × 200.0 ml
M=158g
Ethyl alcohol weighs 158g
3)
ρ (density) = Mass / Volume
ρ
_copper = 1896 g / 8.4cm × 5.5cm × 4.6cm
= 1896g / 212.5 
ρ
_copper=8.9 g 
Answer: The total pressure of air in lungs of an individual is 760.28 mm Hg
Explanation:
According to Dalton's law, the total pressure is the sum of individual pressures.

Given :
=total pressure of gases = ?
= partial pressure of oxygen = 100 mm Hg
= partial pressure of nitrogen = 573 mm Hg
= partial pressure of Carbon dioxide = 0.053 atm = 40.28 mm Hg(1 atm = 760 mmHg)
= partial pressure of water vapor = 47 torr = 47 mm Hg (1torr=1 mm Hg)
putting in the values we get:
Thus the total pressure of air in lungs of an individual is 760.28 mm Hg
Answer:
1425 mmHg.
Explanation:
The following data were obtained from the question:
Initial volume (V1) = 1.5 L
Initial pressure (P1) = 1 atm
Final volume (V2) = 0.8 L
Final pressure (P2) =?
Next, we shall determine the final pressure of the gas by using the Boyle's law equation as follow:
P1V1 = P2V2
1 × 1.5 = P2 × 0.8
1.5 = P2 × 0.8
Divide both side by 0.8
P2 = 1.5/0.8
P2 = 1.875 atm
Finally, we shall convert 1.875 atm to mmHg.
This can be obtained as follow:
1 atm = 760 mmHg
Therefore,
1.875 atm = 1.875 × 760 = 1425 mmHg.
Therefore, the new pressure of the gas is 1425 mmHg.
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