C=0.10 mol/l
pH=-lg[H⁺]
HCl = H⁺ + Cl⁻
pH=-lgc
pH=-lg0.10=1.0
pH=1.0
Answer:
D is the answer to this problem
Separa los metales de los no metales. Agregame como amiga, saludos.
A electrochemical reaction is said to be spontaneous, if
Answer 1:
Consider reaction: <span>Ni^2+ (aq) + S^2- (aq) ----> + Ni (s) + S (s)
The cell representation of above reaction is given by;
</span>
![S^{2-}/S // Ni^{2+}/Ni](https://tex.z-dn.net/?f=%20S%5E%7B2-%7D%2FS%20%2F%2F%20%20Ni%5E%7B2%2B%7D%2FNi%20%20)
Hence,
![E^{0}cell = E^{0} Ni^{2+/Ni} - E^{0} S/S^{2-}](https://tex.z-dn.net/?f=%20E%5E%7B0%7Dcell%20%3D%20%20E%5E%7B0%7D%20Ni%5E%7B2%2B%2FNi%7D%20-%20%20E%5E%7B0%7D%20S%2FS%5E%7B2-%7D%20%20%20%20%20)
we know that,
![{E^{0} Ni^{2+}/Ni = -0.25 v](https://tex.z-dn.net/?f=%7BE%5E%7B0%7D%20Ni%5E%7B2%2B%7D%2FNi%20%20%3D%20-0.25%20v%20%20%20%20%20%20)
and
![{E^{0} S/ S^{2-} = -0.47 v](https://tex.z-dn.net/?f=%7BE%5E%7B0%7D%20S%2F%20S%5E%7B2-%7D%20%20%3D%20-0.47%20v%20)
Therefore,
![E^{0} cell](https://tex.z-dn.net/?f=E%5E%7B0%7D%20cell%20)
= - 0.25 - (-0.47) = 0.22 v
Since,
is positive, hence cell reaction is spontaneous
.....................................................................................................................
Answer 2: Consider reaction: <span>Pb^2+ (aq) +H2 (g) ----> Pb (s) +2H^+ (aq)
</span>
The cell representation of above reaction is given by;
![H_{2} / H^{+} // Pb^{2+} /Pb](https://tex.z-dn.net/?f=H_%7B2%7D%20%2F%20%20H%5E%7B%2B%7D%20%2F%2F%20%20Pb%5E%7B2%2B%7D%20%2FPb)
Hence,
![E^{0}cell = E^{0} Pb/Pb^{2+} - E^{0} H_{2}/H^{+}](https://tex.z-dn.net/?f=%20E%5E%7B0%7Dcell%20%3D%20E%5E%7B0%7D%20Pb%2FPb%5E%7B2%2B%7D%20-%20E%5E%7B0%7D%20H_%7B2%7D%2FH%5E%7B%2B%7D%20)
we know that,
![{E^{0} Pb^{2+}/Pb = -0.126 v](https://tex.z-dn.net/?f=%7BE%5E%7B0%7D%20Pb%5E%7B2%2B%7D%2FPb%20%3D%20-0.126%20v%20)
and
![{E^{0} H_{2}/ H^{+} = -0 v](https://tex.z-dn.net/?f=%7BE%5E%7B0%7D%20H_%7B2%7D%2F%20H%5E%7B%2B%7D%20%3D%20-0%20v%20)
Therefore,
![E^{0} cell](https://tex.z-dn.net/?f=E%5E%7B0%7D%20cell%20)
= - 0.126 - 0 = -0.126 v
Since,
is negative, hence cell reaction is non-spontaneous.....................................................................................................................
Answer 3:
Consider reaction: <span>2Ag^+ (aq) + Cr(s) ---> 2 Ag (s) +Cr^2+ (aq)
</span>
The cell representation of above reaction is given by;
![Cr/Cr^{2+} // Ag^{+}/Ag](https://tex.z-dn.net/?f=%20Cr%2FCr%5E%7B2%2B%7D%20%2F%2F%20Ag%5E%7B%2B%7D%2FAg%20)
Hence,
![E^{0}cell = E^{0} Ag^{+}/Ag - E^{0} Cr/Cr^{2+}](https://tex.z-dn.net/?f=%20E%5E%7B0%7Dcell%20%3D%20E%5E%7B0%7D%20Ag%5E%7B%2B%7D%2FAg%20-%20E%5E%7B0%7D%20Cr%2FCr%5E%7B2%2B%7D%20)
we know that,
![{E^{0} Ag^{+}/Ag = -0.22 v](https://tex.z-dn.net/?f=%7BE%5E%7B0%7D%20Ag%5E%7B%2B%7D%2FAg%20%3D%20-0.22%20v%20)
and
![{E^{0} Cr/ Cr^{2+} = -0.913 v](https://tex.z-dn.net/?f=%7BE%5E%7B0%7D%20Cr%2F%20Cr%5E%7B2%2B%7D%20%3D%20-0.913%20v%20)
Therefore,
![E^{0} cell](https://tex.z-dn.net/?f=E%5E%7B0%7D%20cell%20)
= - 0.22 - (-0.913) = 0.693 v
Since,
is positive, hence cell reaction is spontaneous