<u><em>Answer:</em></u>
- The correct option is C.
- Formation of a precipitate
<u><em>Explanation:</em></u>
During a chemical reaction, new substances are formed known as a products, mostly reaction occur and their product is obtained as precipitates.
<u><em>Example</em></u>
Arylidene-2-thiobarbituric acid is obtained as precipitates when aldehyde and thiobarbituric acid react to each other.
melting of a substance
It is just indication of physical changes, like melting of ice, composition remained same as before.
boiling of a substance
It is just indication of physical changes, like boiling of water into vapors, composition remained same as before.
freezing of a substance
It is just indication of physical changes, like freezing of water into ice, composition remained same as before
First you calculate the pOH of the solution:
pH+ pOH = 14
3.25 + pOH = 14
pOH = 14 - 3.25
pOH = 10.75
<span>Concentration of [OH]</span>⁻<span> in solution:
</span>
[ OH⁻ ] =

[ OH⁻ ] = 10^ - 10.75
[OH⁻] = 1.778 x 10⁻¹¹ Mhope this helps !
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, 
there are 8 planets in our solar system 1.Mercury 2.venus 3.earth 4.mars 5.jupiter 6.saturn 7.uranus 8. neptune
Fe O
2 3 is what i would put