The balanced chemical reaction is
NaCl + AgNO3 --> AgCl + NaNO3
To find out if precipitation will occur, we need to calculate the number of
moles acting in the chemical reaction
But Molarity, M=nV, where n is the number of moles and V is the volume in
litres. So n = M/V
number of moles of AgNo3 = 0.02/500 * 10^(-3)
n= 0.04
While n of Sodium chloride = 0.01/0.5 = 0.2. Since there is excess sodium chloride ( twice as much) precipitation will not occur. 2NaCl + 2AgNO3 -->
2AgCl + 2NaNO3. The reaction requires one and not two moles of AgNo3 as evident from the number of moles which is 0.04