Which of the following chemical reactions is a redox reaction? NH4OH (aq) + KCl (aq) KOH (aq) + NH4Cl (aq)

Zn (s) + H2SO4 (aq) ZnSO4 (aq) + H2 (l)

H2SO4 (aq) + CaCl2 (aq) CaSO4 (aq)+ HCl (aq)

HBr (aq) + KOH (aq) KBr (aq) + H2O (l)

1. combine iron and copper (ii) sulfate solution. (hint: iron will form the iron (iii) ion) fe + cuso4 → 2. combine lead (ii) nitrate and potassium iodide solutions. pb(no3)2+ kl → 3. combine magnesium metal and hydrochloric acid solution. mg + hcl → 4. electrolysis (splitting) of water. h2o → 5. burning magnesium. mg + o2 →

The small bags of silica gel you often see in a new shoe box are placed there to control humidity. despite its name, silica gel is a solid. it is a chemically inert, highly porous, amorphous form of sio2. because water vapor readily adsorbs onto the surface of silica gel, it acts as a desiccant. despite not knowing mechanistic details of the adsorption of water onto silica gel, from the information provided you should be able to make an educated guess about the thermodynamic characteristics of the process. predict the signs for δg, δh, and δs for the adsorption of water.

Draw the aromatic compound toluene (methylbenzene). show all hydrogen atoms, including those on the ring.