Question

Consider four different samples: aqueous LiBr , molten LiBr , aqueous AgBr , and molten AgBr . Current run through each sample produces one of the following products at the cathode: solid lithium, solid silver, or hydrogen gas. Match each sample to its cathodic product.Math following to Cathoid Products-Solid Lithium, Solid Silver, and Hydrogen GasSamples1. Aqueous LiBr2. Molten LiBr3. Aqueous AgBr4. Molten AgBr

Answer 1

Answer:

a) Aqueous LiBr = Hydrogen Gas

b) Aqueous AgBr = solid Ag

c) Molten LiBr = solid Li

c) Molten AgBr = Solid Ag

Explanation:

a) Aqueous LiBr

This sample produces Hydrogen gas, because the H+ (conteined in the water) has a reduction potential higher than the Li+ from the salt. Therefore the hydrogen cation will reduce instead of the lithium one and form the gas.

b) Aqueous AgBr

This sample produces Solid Ag, because the Ag+ has a reduction potential higher than the H+ from the water. Therefore the silver cation will reduce instead of the hydrogen one and form the solid.

c) Molten LiBr

In a molten binary salt like LiBr there is only one cation present in the cathod. In this case the Li+, so it will reduce and form solid Li.  

c) Molten AgBr

The same as the item above: there is only one cation present in the cathod. In this case the Ag+, so it will reduce and form solid Ag.