Answer:
The concentration of HI present at equilibrium is 0.471 M.
Explanation:
They all are correct , so with that being said anyone of them can be right
Answer : The rate constant at 785.0 K is, 
Explanation :
According to the Arrhenius equation,

or,
![\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%20R%7D%5B%5Cfrac%7B1%7D%7BT_1%7D-%5Cfrac%7B1%7D%7BT_2%7D%5D)
where,
= rate constant at
= 
= rate constant at
= ?
= activation energy for the reaction = 262 kJ/mole = 262000 J/mole
R = gas constant = 8.314 J/mole.K
= initial temperature = 
= final temperature = 
Now put all the given values in this formula, we get:
![\log (\frac{K_2}{6.1\times 10^{-8}s^{-1}})=\frac{262000J/mole}{2.303\times 8.314J/mole.K}[\frac{1}{600.0K}-\frac{1}{785.0K}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7B6.1%5Ctimes%2010%5E%7B-8%7Ds%5E%7B-1%7D%7D%29%3D%5Cfrac%7B262000J%2Fmole%7D%7B2.303%5Ctimes%208.314J%2Fmole.K%7D%5B%5Cfrac%7B1%7D%7B600.0K%7D-%5Cfrac%7B1%7D%7B785.0K%7D%5D)

Therefore, the rate constant at 785.0 K is, 
Grams of Ca(NO₃)₂ produced : 0.985 g
<h3>Further explanation</h3>
A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
CaCl₂ + 2AgNO₃ → 2AgCl + Ca(NO₃)₂
MW AgNO₃ : 107.9+14+3.16=169.9
mol AgNO₃ :

mol ratio Ca(NO₃)₂ : AgNO₃ = 1 : 2, so mol Ca(NO₃)₂ :

MW Ca(NO₃)₂ : 40.1+2.14+6.16=164.1 g/mol
mass Ca(NO₃)₂ :

Answer:

Explanation:
The work function of the sodium= 495.0 kJ/mol
It means that
1 mole of electrons can be removed by applying of 495.0 kJ of energy.
Also,
1 mole =
So,
electrons can be removed by applying of 495.0 kJ of energy.
1 electron can be removed by applying of
of energy.
Energy required =
Also,
1 kJ = 1000 J
So,
Energy required =
Also,
Where,
h is Plank's constant having value
c is the speed of light having value
So,
Also,
1 m = 10⁻⁹ nm
So,
