<h3>
Answer:</h3>
1 x 10^13 stadiums
<h3>
Explanation:</h3>
From the question;
1 x 10^5 people can fill 1 stadium
We are given, 1 x 10^18 atoms of iron
We are required to determine the number of stadiums that 1 x 10^18 atoms of iron would occupy.
We are going to assume that a stadium would occupy a number of atoms equivalent to the number of people.
Therefore;
One stadium = 1 x 10^5 atoms
Then, to find the number of stadiums that will be occupied by 1 x 10^18 atoms;
No. of stadiums = Total number of atoms ÷ Atoms in a single stadium
= 1 x 10^18 atoms ÷ 1 x 10^5 atoms
= 1 x 10^13 stadiums
Therefore, 1 x 10^18 atoms of iron would occupy 1 x 10^13 stadiums
The mass of ammonium chloride that must be added is : ( A ) 4.7 g
<u>Given data :</u>
Volume of water ( V ) = 250 mL = 0.25 L
pH of solution = 4.85
Kb = 1.8 * 10⁻⁵
Kw = 10⁻¹⁴
Given that the dissolution of NH₄Cl gives NH₄⁺⁺ and Cl⁻ ions the equation is written as :
NH₄CI + H₂O ⇄ NH₃ + H₃O⁺
where conc of H₃O⁺
[ H₃O⁺ ] =
and Ka = Kw / Kb
∴ Ka = 5.56 * 10⁻¹⁰
Next step : Determine the concentration of H₃O⁺ in the solution
pH = - log [ H₃O⁺ ] = 4.85
∴ [ H₃O⁺ ] in the solution = 1.14125 * 10⁻⁵
Next step : Determine the concentration of NH₄CI in the solution
C = [ H₃O⁺ ]² / Ka
= ( 1.14125 * 10⁻⁵ )² / 5.56 * 10⁻¹⁰
= 0.359 mol / L
Determine the number of moles of NH₄CI in the solution
n = C . V
= 0.359 mol / L * 0.25 L = 0.08979 mole
Final step : determine the mass of ammonium chloride that must be added to 250 mL
mass = n * molar mass
= 0.08979 * 53.5 g/mol
= 4.80 g ≈ 4.7 grams
Therefore we can conclude that the mass of ammonium chloride that must be added is 4.7 g
Learn more about ammonium chloride : brainly.com/question/13050932
Acid rain falls in areas that have air pollution. (<span>Acid rain is caused by emissions of </span>sulfur dioxide<span> and </span>nitrogen oxide)