A positive ion is —————-than its parent atom?

What is the molarity of a solution that is prepared by adding 57.1 g of toluene (c 7 h 8 ) (density = 0.867 g/ml) to a 250 ml volumetric flask, and then filling to the mark with benzene (c 6 h 6 ) (density = 0.876 g/ml)?

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it