1. First taking in light, then electron transport
2. A main fuel for your brain. Without it, your brain wouldn't function well. Yes, you need it.
Answer:
pH of soltion will be 5.69
Explanation:
The pH of the solution will be due to excessive acid left and the salt formed. Thus, it will form a buffer solution.
The pH of buffer solution is calculated from Henderson Hassalbalch's equation, which is:
![pH=pKa+log(\frac{[salt]}{[acid]} )](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%20%29)


The moles of acid taken :

The moles of base taken:

The moles of acid left after reaction :

The moles of salt formed = 4.5mmol
Putting values in equation
![pH=pKa+log(\frac{[salt]}{[acid]} )=4.74+log(\frac{4.5}{0.5})=5.69](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D%20%29%3D4.74%2Blog%28%5Cfrac%7B4.5%7D%7B0.5%7D%29%3D5.69)
The given substance is SOLID. Solids have definite shape and definite volume. By the term definite we mean that wherever it may be placed both shape and volume remain the same. From the given above, the substance has a definite shape of sphere and definite volume of 50 mL.
Mass, if you know what element you are working with.