PLEASE PLEASE PLEASE HEL I NEED HELP ON A CHEMISTRY TEST ALSO PLEASE SHOW ALL WORK AND NO LINKS THANKS

18. Calculate the molarity of each solution below. Show ALL work, units and labels.

a) 1.23 g Na2SO4 in 1.00 L of solution

b) 2.34 g CaCl2 in 0.750 L of solution

c) 45.60 g Pb(NO3)2 in 900.0 mL of solution

19. Calculate the mass of solid is needed to prepare the volume and molarity of each solution below. Show ALL work, units and labels.

a) 750. mL of 0.500 M Na2SO4

b) 500. mL of 1.50 M CaCl2

c) 10.00 L of 1.500 M Pb(NO3)2

20. Calculate the number of milliliters of solution that contain the designated number of grams of solute. Show ALL work, units and labels.

a) 2.48 M Na2SO4 containing 31.2 g solute

b) 3.69 M CaCl2 containing 23.1 g solute

c) 0.6543 M Pb(NO3)2 containing 1.098 g solute

lol idk man i guess u gotta ask bill nye the science guy

you need to have a picture of the atom that way we can answer it

answer : (a) volume of the gas = 8.67 ×   l

                (b) second virial coefficient b = -1.21226 l/mole

solution :   given,     t = 300k

                                p = 20atm

                                z = 0.86

                                n = 8.2 mmoles = 8.2 × moles

                                r =   0.082 l atm/k/mol

        find,     (a) volume of gas   and (b) second virial coefficient b at 300k.

formula used :            

                          and            

(a)            

                    = \times 0.082\times 300}{20}[/tex]

                    = 8.67 ×   l

(b)      

                    = (0.00867-1) × 8.659

                    = - 8.5839 l/mole

the correct answer would be b. amelia, because the particals of gas move really fast (charged particals) and gas also has a lot of room (particals move independently) so the only answer that has both of those is amelia's.