There are 2 significant figures.
"Rule 3: Trailing zeros are significant if a decimal point is shown in the number, but may or may not be significant if no decimal point is shown."
Answer:
5.65 is the pH.
Explanation:
I am assuming that you are asking for confirmation on your answer. The answer is 5.65.
You would do:
[pOH] = -log[OH-]
= -log[4.5*10^-9]
equals about 8.3468
To find pH your would subtract the pOH from 14.
14-8.3468 = 5.65 << Rounded to match the answer choices.
Given :
Molarity of sulfuric acid solution is 3.0 M.
Amount of sulfuric acid present in solution is 9.809 g.
To Find :
The volume of solution.
Solution :
We know, molarity is given by :

Therefore, volume required is 33.33 ml .
To calculate the new pressure, we can use Boyle’s law to relate these two scenarios (Boyle’s law is used because the temperature is assumed to remain constant). Boyle’s law is:
P1V1 = P2V2,
Where “P” is pressure and “V” is volume. The pressure and volume of the first scenario is 215 torr and 51 mL, respectively, and the second scenario has a volume of 18.5 L (18,500 mL) and the unknown pressure - let’s call that “x”. Plugging these into the equation:
(215 torr)(51 mL) =(“x” torr)(18,500 mL)
x = 0.593 torr
The final pressure exerted by the gas would be 0.593 torr.
Hope this helps!