A student is given a soluble sodium salt containing one of eight possible anions (negative ions): acetate, chloride, bromide, iodide, sulfide, sulfate, and phosphate. The student adds some BaCl2 solution to the salt solution. A precipitate forms. Which anions could be present?
1 SO42- and PO43-
2 Cl-, Br-, and I-
3. Br- only
4. CH3COO- only
If solutions of Co(NO3)3 and KOH are mixed, how many precipitation reactions will occur?
1. zero
2.one
3. two
4 three
In which system does a spontaneous redox reaction produce electrical energy?
1electrochemical cell
2electrolytic cell
3 electroplating cell
4 half-cell