0001 M HCl is the same as saying that 1 *10-4 moles of H+ ions have been added to solution. The -log[. 0001] =4, so the pH of the solution =4.
40.0 g ( 1 mole ) --------------- 6.02x10²³ molecules
? ? --------------------------- 2.90x10²² molecules
mass = 2.90x10²² * 40.0 / 6.02x10²³
mass = 1.16x10²⁴ / 6.02x10²³
mass = 1.9269 g
hope this helps!
Answer: A, 1.3*1020, 1326
A. 1326
B. 2960.9
C. 9804
D. 8559.6