The answer is 2.37 x10^22 atoms
The substance you would expect to have a low melting point would be carbon dioxide, so the correct answer would be A
Answer:
The molar solubility of lead bromide at 298K is 0.010 mol/L.
Explanation:
In order to solve this problem, we need to use the Nernst Equaiton:
![E = E^{o} - \frac{0.0591}{n} log\frac{[ox]}{[red]}](https://tex.z-dn.net/?f=E%20%3D%20E%5E%7Bo%7D%20-%20%5Cfrac%7B0.0591%7D%7Bn%7D%20log%5Cfrac%7B%5Box%5D%7D%7B%5Bred%5D%7D)
E is the cell potential at a certain instant, E⁰ is the cell potential, n is the number of electrons involved in the redox reaction, [ox] is the concentration of the oxidated specie and [red] is the concentration of the reduced specie.
At equilibrium, E = 0, therefore:
![E^{o} = \frac{0.0591}{n} log \frac{[ox]}{[red]} \\\\log \frac{[ox]}{[red]} = \frac{nE^{o} }{0.0591} \\\\log[red] = log[ox] - \frac{nE^{o} }{0.0591}\\\\[red] = 10^{ log[ox] - \frac{nE^{o} }{0.0591}} \\\\[red] = 10^{ log0.733 - \frac{2x5.45x10^{-2} }{0.0591}}\\\\](https://tex.z-dn.net/?f=E%5E%7Bo%7D%20%20%3D%20%5Cfrac%7B0.0591%7D%7Bn%7D%20log%20%5Cfrac%7B%5Box%5D%7D%7B%5Bred%5D%7D%20%5C%5C%5C%5Clog%20%5Cfrac%7B%5Box%5D%7D%7B%5Bred%5D%7D%20%3D%20%5Cfrac%7BnE%5E%7Bo%7D%20%7D%7B0.0591%7D%20%5C%5C%5C%5Clog%5Bred%5D%20%3D%20%20log%5Box%5D%20-%20%20%5Cfrac%7BnE%5E%7Bo%7D%20%7D%7B0.0591%7D%5C%5C%5C%5C%5Bred%5D%20%3D%2010%5E%7B%20log%5Box%5D%20-%20%20%5Cfrac%7BnE%5E%7Bo%7D%20%7D%7B0.0591%7D%7D%20%5C%5C%5C%5C%5Bred%5D%20%3D%2010%5E%7B%20log0.733%20-%20%20%5Cfrac%7B2x5.45x10%5E%7B-2%7D%20%20%7D%7B0.0591%7D%7D%5C%5C%5C%5C)
[red] = 0.010 M
The reduction will happen in the anode, therefore, the concentration of the reduced specie is equivalent to the molar solubility of lead bromide.
Answer:
kJ/mol
Explanation:
Given and known facts
Mass of Benzene
grams
Mass of water
grams
Standard heat capacity of water
J/g∙°C
Change in temperature ΔT
°C
Heat

Heat released by benzine is - 7.82 kJ
Now, we know that
grams of benzene release
kJ heat
So,
g benzine releases

kJ/g
mol C6H6
Heat released

kJ/mol
Answer
_2 HNO₃ + 1 Mg(OH)₂ → 1 Mg(NO₃)₂ + 2 H₂O
Explanation
Given:
______HNO3 + Mg(OH)2 ------>
Solution:
Note that the reaction between an acid and a base will give salt and water only.
Hence the complete reaction of the given equation is:
___HNO₃ + Mg(OH)₂ → Mg(NO₃)₂ + H₂O
To get the balanced equation for the acid-base reaction, 2 moles of HNO₃ will react with 1 mole of Mg(OH)₂ to produced 1 mole of Mg(NO₃)₂ and 2 moles of H₂O.
Therefore, the complete and balanced equation for the given acid-base reaction is:
_2 HNO₃ + 1 Mg(OH)₂ → 1 Mg(NO₃)₂ + 2 H₂O