Number of moles = number of atoms/Avogadro's number
= (4.8x10^25)/(6.02x10^23)
=79.7 mol (3sf)
A buffer is a solution that can resist pH change upon the addition of an acidic or basic components. It is able to neutralize small amounts of added acid or base, thus maintaining the pH of the solution relatively stable.
Answer: B. 0.015 mole/L
Explanation:
To calculate the number of moles for given molarity, we use the equation:
.....(1)
Molarity of 
solution = 0.010 M
Volume of solution = 10 mL
Putting values in equation 1, we get:
a) 
1 mole of contains = 1 mol of 
Thus 
of contain= 
mol of
b) 
1 mole of 
contains = 2 mol of
Thus of contain= 
mol of
Total ![[Na^+]=\frac {\text {total moles}}{\text {total volume}}=\frac{10^{-4}+2\times 10^{-4}}{0.02L}=0.015M](https://tex.z-dn.net/?f=%5BNa%5E%2B%5D%3D%5Cfrac%20%7B%5Ctext%20%7Btotal%20moles%7D%7D%7B%5Ctext%20%7Btotal%20volume%7D%7D%3D%5Cfrac%7B10%5E%7B-4%7D%2B2%5Ctimes%2010%5E%7B-4%7D%7D%7B0.02L%7D%3D0.015M)
The molar concentration of in a solution is 0.015 M
Answer: A. PV
Explanation: In Boyles Law it is a concept on ideal gases which states the relationship between volume and absolute pressure of the gas is inversely proportional. The relationship can be expressed in PV = k where k is a proportionality constant.
