Please I need the answer fast Calculate the pH value in a solution that has a concentration of 0.04 mol/dm3+ ions

How manyatoms of mercury are in 1.4214e+1 ml sample

Stage in which a star’s outer layers have started to cool and grow outward?

8) a mixture of he, ne and ar has a pressure of 7.85 atm. if the ne has a mole fraction of 0.47 and 8) ar has a mole fraction of 0.23, what is the pressure of he? a) 4.2 atm b) 3.7 atm c) 5.5 atm d) 2.4 atm e) 1.8 atm