MULTIPLE CHOICE1.\(n(SO_2)=\frac{1}{2}n(O_2)\) and \(PV=nRT\)
\(\therefore P(SO_2)=\frac{1}{2}P(O_2)\\ =50kPa\)
(B)2.
I:
correct (\(Cd(OH)_2\) reduced to \(Cd\) at the the cathode)
II:
incorrect (no net change in \([OH^-]\) so no change to pH)
III:
correct (electrons flow from anode to cathode in electrolysis)
(D)3. \(\frac{3}{M_R(Au)}:\frac{1}{M_R(Ag)}\approx1.6:1\)
(C)SHORT ANSWERa) \(C_2H_5OH_{(aq)}+H_2O_{(l)}\rightarrow\ CH_3COOH_{(aq)}+4H^+_{(aq)}+4e^-\)
b) \(Q=It=n(e^-)\times\ F\) and \(4n(C_2H_5OH) = n(e^-)\) when \(t=1\)
\(\therefore n(e^-)=4n(C_2H_5OH)=\frac{3.0\times\ 10^{-5}g}{M_R(C_2H_5OH)}\times\ 4 \\ \therefore Q=\frac{3.0\times\ 10^{-5}g}{46.0gmol^{-1}}\times\ 4 \times\ 96500Cmol^{-1} \\ \approx0.25A\)
c)
- Provide surface area for reactants to contact catalysts
- Unreactive and prevents spontaneous reactions (directly between reactants and between electrodes and reactants)