Remember pH is defined as: pH = -log[H+]
so, substituting
4 = - log[H+]
-4 = log [H+] Take antilog of both sides
10^(-4) = [H+]
[H+] = 1 x 10^-4 M
2.03 kg = 2030 grams
2030g C6H8O7 (1 mol/ 192.124g) = 10.6 mol C6H8O7
Yes, 50 pennies plus 50 pennies equals 100 pennies minus 50pennies equals 50 pennies.
I'm pretty sure its the weight of the book
