Answer: Molarity of the prepared solution is 
Explanation:
Molarity is defined as the number of moles of solute dissolved per liter of the solution.
where,
n= moles of solute
= volume of solution in ml = 500 ml
moles of solute =
Now put all the given values in the formula of molarity, we get
Thus molarity of the prepared solution is
20 molecules minus ten degrees equals 1001
Answer:
pH = 10.9
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to say that the undergoing reaction between this buffer and OH⁻ promotes the formation of more CO₃²⁻ because it acts as the base, we can do the following:
The resulting concentrations are:
![[CO_3^{2-}]=\frac{0.1435mol}{0.25L}=0.574M \\](https://tex.z-dn.net/?f=%5BCO_3%5E%7B2-%7D%5D%3D%5Cfrac%7B0.1435mol%7D%7B0.25L%7D%3D0.574M%20%5C%5C)
![[HCO_3^{-}]=\frac{0.0265mol}{0.25L}=0.106M](https://tex.z-dn.net/?f=%5BHCO_3%5E%7B-%7D%5D%3D%5Cfrac%7B0.0265mol%7D%7B0.25L%7D%3D0.106M)
Thus, since the pKa of this buffer system is 10.2, the change in the pH would be:
Which makes sense since basic OH⁻ ions were added.
Regards!
A theory may not be right, but a law is. :)
Option B: 4.3
There are following rules for rounding off numbers:
1. If the rounding digit has digit less than 5 (1,2,3 and 4) to its right, all the digits on right side of the rounding digit will drop out.
2. If the rounding digit has digit equal and greater than 5 (5,6,7,8 and 9) to its right, one is added to the rounding digit.
Jeff has to weigh 4.312 g sample of NaCl. To round off the underline number 4.<u>3</u>12, check for the digit right to it. It has 1, which is less than 5 thus according to the Rule 1, all the digits on right side of the rounding digit will drop out and the number gets rounded off to 4.3.
Therefore, 4.3 is most accurate measurement by Jeff.
