a) When the reaction takes place a yellow precipitate will be formed.
b) The law of conservation of mass is true.
<u>Explanation:</u>
a) When a lead nitrate solution is mixed with a potassium chromate solution, a yellow precipitate containing lead forms according to the equation:
→ 
b) Law of conservation of mass for the given reaction is true.
From the given table we know the mass of reactants and its products.
Law of conservation of mass is a principle when a reaction takes place in a closed system, the mass of the products and reactants in the system doesn't change.
⇒The sum of the mass of the reactants = The sum of the mass of the products.
The sum of the reactants = 128.71+128.97.
= 257.68 g.
The sum of the products = 154.10+103.58.
= 257.68 g.
Thus law of conservation of mass is true for the above reaction.
<span>So the oxidizing agent will receive electrons from the reducing agent and the oxidation agent will take electrons from the reducing agent.</span>
<span>Raising
the temperature of the reactants increases the reaction between the reactants.
The kinetic energy of the molecules of the reactants collides more frequently
with ach other thereby increasing its reaction. Increasing the concentration of
the reactants increases the reaction rate. Adding a catalyst to the reaction
increases the rate of reaction of a substance. The catalyst hastens the
chemical reaction. </span>