The person above above above me is very very good awnswer hope this helps
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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
Lets say foxes hunt rabbits. If their are too many foxes then they will compete for the rabbits. The rabbits get outnumbered by the amount of foxes so the foxes kill all the rabbits and the rabbits could eventually go extinct.
Answer: 483 mL of the cleaning solution are used to clean hospital equipment
Explanation:
The question requires us to calculate the volume, in mL, of solution is used to clean hospital equipment, given that 415g of this solution are used and the specific gravity of the solution is 0.860.
Measurements > Density
Specific gravity is defined as the ratio between the density of a given substance to the density of a reference material, such as water:

The density of a substance is defined as the ratio between the mass and the volume of this substance:

Considering the reference substance as water and its density as 1.00 g/mL, we can determine the density of the substance which specific gravity is 0.860:

Thus, taking water as the reference substance, we can say that the density of the cleaning solution is 0.860 g/mL.
Now that we know the density of the cleaning solution (0.860 g/mL) and the mass of solution that is used to clean hospital equipment (415g), we can calculate the volume of solution that is used to clean the equipment:

Therefore, 483 mL of the cleaning solution are used to clean hospital equipment.