Answer:

Explanation:
Regardless of the type of gas, 1 mole at standard temperature and pressure (STP) occupies a volume of 22.4 liters. In this case the gas is helium (He).
We can set up a ratio.

Multiply by the given number of moles.

The moles of helium will cancel.


Multiply.

5.25 moles of helium gas at STP is 117.6 liters of helium.
<span>Electronegativity is the property of an element that measures the
ability of it to attract and form electron bonds. The trend in the periodic
table in terms of electronegativity decreases from right to left and from top
to bottom. In the case of period 4, the element with the highest electronegativity
is bromine. </span>
Answer:
The molar mass of the gas is 36.25 g/mol.
Explanation:
- To solve this problem, we can use the mathematical relation:
ν = 
Where, ν is the speed of light in a gas <em>(ν = 449 m/s)</em>,
R is the universal gas constant <em>(R = 8.314 J/mol.K)</em>,
T is the temperature of the gas in Kelvin <em>(T = 20 °C + 273 = 293 K)</em>,
M is the molar mass of the gas in <em>(Kg/mol)</em>.
ν = 
(449 m/s) = √ (3(8.314 J/mol.K) (293 K) / M,
<em>by squaring the two sides:</em>
(449 m/s)² = (3 (8.314 J/mol.K) (293 K)) / M,
∴ M = (3 (8.314 J/mol.K) (293 K) / (449 m/s)² = 7308.006 / 201601 = 0.03625 Kg/mol.
<em>∴ The molar mass of the gas is 36.25 g/mol.</em>
Answer:
T₂ = 317.87 K
Explanation:
Given data:
Initial pressure = 15 atm
Final pressure = 16 atm
Initial temperature = 298 K
Final temperature = ?
Solution:
According to Gay-Lussac Law,
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
15 atm / 298K = 16 atm/T₂
T₂ = 16atm × 298 K / 15 atm
T₂ = 4768 atm. K / 15 atm
T₂ = 317.87 K
hydrogen is the lightest element in the periodic table