Answer:

Explanation:
HA + H₂O ⇌ H₃O⁺ + A⁻
1. Calculate pKₐ

2. Calculate the pH
We can use the Henderson-Hasselbalch equation to get the pH.
![\begin{array}{rcl}\text{pH} & = & \text{pK}_{\text{a}} + \log \left(\dfrac{[\text{A}^{-}]}{\text{[HA]}}\right )\\\\& = & 4.89 +\log \left(\dfrac{0.42}{0.23}\right )\\\\& = & 4.89 + \log1.83 \\& = & 4.89 +0.261\\& = & 5.15\\\end{array}\\\text{The pH of the buffer is $\large \boxed{\mathbf{5.15}}$}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7D%5Ctext%7BpH%7D%20%26%20%3D%20%26%20%5Ctext%7BpK%7D_%7B%5Ctext%7Ba%7D%7D%20%2B%20%5Clog%20%5Cleft%28%5Cdfrac%7B%5B%5Ctext%7BA%7D%5E%7B-%7D%5D%7D%7B%5Ctext%7B%5BHA%5D%7D%7D%5Cright%20%29%5C%5C%5C%5C%26%20%3D%20%26%204.89%20%2B%5Clog%20%5Cleft%28%5Cdfrac%7B0.42%7D%7B0.23%7D%5Cright%20%29%5C%5C%5C%5C%26%20%3D%20%26%204.89%20%2B%20%5Clog1.83%20%5C%5C%26%20%3D%20%26%204.89%20%2B0.261%5C%5C%26%20%3D%20%26%205.15%5C%5C%5Cend%7Barray%7D%5C%5C%5Ctext%7BThe%20pH%20of%20the%20buffer%20is%20%24%5Clarge%20%5Cboxed%7B%5Cmathbf%7B5.15%7D%7D%24%7D)
Answer:
It reacts with metals to form metal hydroxide and hydrogen gas. it s an chemical property and it decomposes to H2 and O2 is also another chemical property property. because in these reaction H2O has changed to something else hence are called chemical property.
Explanation:
Number of moles:
1 mole ---------- 6.02x10²³ molecules
? moles --------- 9.45x10²⁴ molecules
1 x ( 9.45x10²⁴) / 6.02x10²³ =
9.45x10²⁴ / 6.02x10²³ => 15.69 moles of CH3OH
Therefore:
Molar mass CH3OH = 32.04 g/mol
1 mole ------------ 32.04 g
15.69 moles ----- mass methanol
Mass methanol = 15.69 x 32.04 / 1 => 502.7076 g