Nope, you are correct! The precipitate of a solution is the solid that forms when two of them are mixed. PbI2 is the only solid, so it must be the precipitate!
The amount of the solute is constant during dilution. So the mole number of HCl is 2*1.5=3 mole. The volume of HCl stock is 3/12=0.25 L. So using 0.25 L stock solution and dilute to 2.0 L.
Both containers have the same number of molecules= 5.62 x 10²³
<h3>Further explanation</h3>
Given
22.4 L of hydrogen gas
22.4 L of oxygen gas
25°C and 1 atm.
Required
true statement
Solution
Conditions at T 25 ° C and P 1 atm are stated by RTP (Room Temperature and Pressure). Vm in this condition = 24 liters / mol
and from Avogadro's Law :
<em>At the same temperature and pressure, the ratio of gas volume will be equal to the ratio of gas moles </em>
So two gas have the same molecules
1 mol = 6.02 x 10²³ molecules
24 L = 1 mol, so for 22.4 L :