Answer: Volume would be 196.15 mL if the temperature were changed to 
and the pressure to 1.25 atmospheres.
Explanation:
Given: 
, 
= 256 mL,
= 720 torr (1 torr = 0.00131579 atm) = 0.947368 atm
, 
Formula used to calculate volume is as follows.
Substitute the values into above formula as follows.
Thus, we can conclude that the volume would be 196.15 mL if the temperature were changed to and the pressure to 1.25 atmospheres.
<span>Let's </span>assume that the gas has ideal gas behavior. <span>
Then we can use ideal gas formula,
PV = nRT<span>
</span><span>Where, P is the pressure of the gas (Pa), V
is the volume of the gas (m³), n is the number
of moles of gas (mol), R is the universal gas constant ( 8.314 J mol</span></span>⁻¹ K⁻¹)
and T is temperature in Kelvin.<span>
<span>
</span>P = 60 cm Hg = 79993.4 Pa
V = </span>125 mL = 125 x 10⁻⁶ m³
n = ?
<span>
R = 8.314 J mol</span>⁻¹ K⁻¹<span>
T = 25 °C = 298 K
<span>
By substitution,
</span></span>79993.4 Pa<span> x </span>125 x 10⁻⁶ m³ = n x 8.314 J mol⁻¹ K⁻¹ x 298 K<span>
n = 4.0359 x 10</span>⁻³ mol
<span>
Hence, moles of the gas</span> = 4.0359 x 10⁻³ mol<span>
Moles = mass / molar
mass
</span>Mass of the gas = 0.529 g
<span>Molar mass of the gas</span> = mass / number of moles<span>
= </span>0.529 g / 4.0359 x 10⁻³ mol<span>
<span> = </span>131.07 g mol</span>⁻¹<span>
Hence, the molar mass of the given gas is </span>131.07 g mol⁻¹
The mass number of this particular element is 37
An element with 17 protons will ALWAYS be chlorine.
The mass number is found by adding the element’s protons and neutrons.
protons+neutrons=mass number
Here is the math if needed,
17+20=37
Therefore the mass number is 37
I hope this helped!
