Answer: Option (A) is the correct answer.
Explanation:
When there is a change in chemical bonding of atoms between one or more compounds then it results in the formation of new compounds. This is known as chemical change.
For example, is a chemical change as there occurs change in identity and properties of the reactants.
Chemical changes can cause change in color, evolution of bubbles, and formation of precipitate.
Thus, we can conclude that the statement both the identity and the properties of a substance change best describes what happens during a chemical change.
Explanation:
The ideal gas law is written as
where are the pressure, volume and temperature,
is the number of moles of gas; and
is the ideal gas constant. It is the same for all gases.
Given,
Since,
So,the number of moles is
Answer: 1.61 x 10⁴ kPa
Dalton's law <u>states that the sum of the partial pressures of each gas equals the total pressure of the gas mixture.</u> According to this law,
Pi = xi P
where Pi is the partial pressure of the gas i, xi is the mole fraction of the gas i in the gas mixture and P is the total pressure.
The mole fraction <u>is defined as the quotient between the moles of solute (ni) and the total moles of the mixture (nt)</u>, which is calculated by adding the moles of all its components:
xi =
In the Trimix 10/50 mix you have 10% oxygen, 50% helium and 40% nitrogen.
To calculate the total number of moles of the mixture and thus determine the molar fraction of helium, we consider 100 g and calculate the number of moles that represent 10 g of O₂ (n₁), 50 g of He (n₂) and 40 g of N₂ (n₃):
n₁ = 10 g x = 0.313 mol
n₂ = 50 g x = 6.246 mol
n₃ = 40 g x = 1.428 mol
Then the total number of moles (nt) will be:
nt = n₁ + n₂ + n₃ = 0.313 mol + 6.246 mol +1.428 mol
nt = 7,987 mol
Then, the mole fraction of helium (x₂) in the mixture will be,
x₂ = = 0.78
and the partial pressure of helium in the mixture, according to Dalton's law, will be:
P₂ = x₂ P = 0.78 x 2.07 x 10⁴ kPa
P₂= 1.61 x 10⁴ kPa
So, <u>the partial pressure of helium if a tank of trimix 10/50 has a total pressure of 2.07 x 104 kPa is 1.61 x 10⁴ kPa</u>