Answer:
1) The reaction rate is double with respect to that reactant
Explanation:
Hello,
By considering the rate law:

If we double the reactant A concentration, by definition, the rate will be doubled as well since the
power is one (order 1), this could be proved just by checking it out in the rate law.
Best regards.
Answer;
K+ and NO3- ions
Explanation;
The main ions remaining are K+ and NO3- ions after pbi2 precipitation is complete.
However; There will always be tiny amounts of Pb2+ and I- ions, but most of them are in the solid precipitate.
6 sodium and 6 Bromine in 6NaBr