Question

my teacher helped but when i type my answer (1.68e15) on my webassign it says its wrong :In 1 mL of water there are 3. 1022 molecules of H2O. How many hydrogen ions are in 28 mL of water? (Hint: In 1 billion water molecules, only 2 are ionized.)

Answer 1

I think you meant 3* 10^22 molecules.
1 ml -> 3*10^22 molecules.
28 ml-> 28*3*10^22 molecules
So you have 28*3*10^22 molecules of water.
Now 1 billion molecules of water -> 2 H+ ions
so 28*3*10^22 molecules -> 28*3*10^22*2/1 billion. Which would be the answer.

Answer 2

I think your answer would be correct.

Answer 3

Unless there's a typo.. Assuming 1L of water weighs 1kg. 1ml would weigh 1g. which would mean 0.0555 moles.
Molecules= 0.0555*6.022*10^23=0.33445*10^23.= 3.34*10^22. Your answer should be the correct answer only.

Answer 4

there must be a typo somewhere. iv'e been trying this for over 30 minutes haha