Answer:
19g
Explanation:
Given:
Number of molecules = 1.505 x 10²³molecules
Formula of compound = CS₂
Unknown:
Mass of the compound
Solution:
A mole of every substance contains 6.02 x 10²³molecules. Using this we can find the number of moles from number of molecules given;
6.02 x 10²³molecules makes up 1 mole of a substance
1.505 x 10²³molecules will contain = 0.25mole of CS₂
Mass of CS₂ = number of moles x molar mass
Molar mass of CS₂ = 12 + 2(32) = 76g/mol
Mass of CS₂ = 0.25 x 76 = 19g
<u>Answer:</u> The pH of the solution is 9.71
<u>Explanation:</u>
1 mole of NaOH produces 1 mole of sodium ions and 1 mole of hydroxide ions.
We are given:
pOH of the solution = 7.2
To calculate the pH of the solution, we need to determine pOH of the solution. To calculate pOh of the solution, we use the equation:
We are given:
Putting values in above equation, we get:
To calculate pH of the solution, we use the equation:
Hence, the pH of the solution is 9.71
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>