Please help with this... 4. What is the pH of a 4.7 x 10-9 M HCl solution? a. 4.67 b.- 8.33 c. 11.21 d. 2.93​

At 300 mm hg, a gas has a volume of 380 l, what is the volume at standard pressure

Diffraction is when light is bent around obstructions. which of the these observation about clouds would indicate diffraction? a) after rain storms, you can sometimes see rainbows. b) clouds are white or gray and cannot be seen through. c) on a cloudy day, the temperature tends to be cooler than a sunny day. d) the edges of dark clouds appear lighter. this

Which of your 24 wells had indications that a chemical reaction occurred? how were you able to tell that a chemical reaction occurred? which of your 24 wells had indications that a physical reaction occurred? how were you able to tell that a physical reaction occurred? report on both mixing and evaporation. make a general statement about whether your hypotheses were validated or rejected. must your hypotheses be correct for this to be a successful laboratory?