Answer 1) : The density of the hot air inside the balloon can be found out by using ideal gas equation;
PV = nRT;
As n is number of moles and in gases, number of moles along with mass per mole is equal to the density of the gas.
If the moles in the gas are more the density will be more.
here, density (ρ) = mass (m) / volume (V); substituting in the ideal gas equation we get,
ρ = mP / RT
Answer 2) ρ (hot air) = ρ (cold air) X 
Here according to the formula because T(hot air) >T(cold air),
So, the density of hot air greater than the density of cold air.
The relationship between the ρ (h) = ρ(c) X
Answer:
Barium precipitation : in this method we will add Barium chloride to the wastewater to precipitate Barium sulphate precipitate from the waste water
Explanation:
The measures that can be taken for the recovery of sulfates and other contaminants from wastewater includes : ion exchange, precipitation and Reverse osmosis. of all these measures i will discuss precipitation
Precipitation measures can be performed using different methodologies the methodology that i will discuss is :
Barium precipitation : in this method we will add Barium chloride to the wastewater to precipitate Barium sulphate precipitate from the waste water
The sulphate contained in the wastewater can be reduced to as low as 200 mg/l using this method
Temperature : the increase in temperature of the waste water will cause the reduction in formation of sulphate in the waste water
PH changes : for the precipitation of sulphate to be effective the required PH level is 4.5
Tectonic plate shifting...
The formula is:
frequency * h (Planck's constant) = Energy
So, to find frequency you need just divide energy by the constant:
frequency = (8 * 10^-15 J) / (6.63 * 10^-34 J*s) = 1.2 * 10^19 1/s or 1.2 * 10^19 Hz
