<h3>
Answer:</h3>
250.756 moles He
<h3>
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
im pretty sure its A if i did all my reasearch right.
hope this helps luv. <3
<u>Answer:</u> The molecules of oxygen gas that will be reduced to water are 42 molecules
<u>Explanation:</u>
We are given:
The substance having highest positive 
potential will always get reduced and will undergo reduction reaction. Here, oxygen will undergo reduction reaction will get reduced.
will undergo oxidation reaction and will get oxidized.
Substance getting oxidized always act as anode and the one getting reduced always act as cathode.
The half reactions follows:
<u>Oxidation half reaction:</u> 
( × 4)
<u>Reduction half reaction:</u> 
( × 6)
<u>Overall reaction:</u> 
We are given:
Molecules of = 28
By Stoichiometry of the reaction:
4 molecules of reacts with 6 molecules of oxygen gas
So, 28 molecules of will react with = 
molecules of oxygen gas
Hence, the molecules of oxygen gas that will be reduced to water are 42 molecules
Answer:
a. forces acting on the object
C=10⁻⁶ mol/L
pH=14-pOH
pOH=-lg[OH⁻]
pH=14+lg10⁻⁶=14-6=8
B. pH = 8
