<h3>
Answer:</h3>
250.756 moles He
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Explanation:</h3>
From the question we are given;
Volume, L = 685 L
Temperature, T = 621 K
Pressure, P = 189 × 10 kPa
We are required to calculate the number of moles of the gas,
Using the Ideal gas equation,
PV = nRT, where P is the pressure, V is the volume, T is the temperature, n is the number of moles, and R is the ideal gas constant.
We can replace the known variables and constant in the equation to get the unknown variable, n.
Using ideal gas constant as 8.3145 L.kPa/K/mol



n = 250.756 moles
The moles of helium contained in the sphere is 250.756 moles
Answer:
Percentage of oxygen = 30%
Percentage of carbon = 30%
Percentage of hydrogen = 40%
Explanation:
Formula:
Percentage of element = given amount / total amount × 100
Given compound:
C₆H₈O₆
Number of atoms of carbon = 6
Number of atoms of hydrogen = 8
Number of atoms of oxygen = 6
Total number of atoms = 20
Percentage of carbon = 6/20 × 100
Percentage of carbon = 30%
Percentage of Hydrogen = 8/20 × 100
Percentage of Hydrogen = 40%
Percentage of oxygen = 6/20 × 100
Percentage of oxygen = 30%
Answer:
Because of the ground above and the molten iron core.
Explanation:
As you go deeper into the earth you have more and more of the earth above you that applies pressure on you. The heat near the very top of the plate is relatively low and it decreases by a little as you go down. But once you start to go down into the earth by hundreds of meters then the temperature starts to rise and it rises pretty quickly due to the heat being transferred from the molten iron outer core of the earth.
The answer is C I got it right so hope it helped ;)