Explanation:
subscript is K
superscript is ^
subscript K means a unit of temperature like F or C
superscript ^ means to the power of
So all together it means to the power of 40 K
I'd say that the answer is erosion
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
1. Potential Energy is stored energy a object has when it's not moving.
2. Potential Energy is it's highest on the first stage because as you see the roller coaster is bout to go down the tract which is going to higher the kinetic energy and lower the potential energy.
3. Kinetic Energy is the amount of energy a object has when it's in motion or moving.
4. Kinetic Energy is it's highest in the third stage after it's gone down the tract and potential energy fully decreased and it's at zero.
Remember that potential energy is stored energy so when a object is not moving in this case the roller coaster isn't moving on the first stage when its bout to go down the roller coaster. Kinetic energy is the amount of energy a object has when it's in motion so in this case the third stage would have the highest example of Kinetic energy because it's fully in motion and has no potential energy.
To determine the number of potassium laid side by side by a given distance, we simply divide the total distance to the diameter of each atom. The diameter is twice the radius of the atom. We calculate as follows:
number of atoms = 4770 / 231x10^-12 = 2.06x10^13 atoms
