Answer:
pH of Buffer Solution 5.69
Explanation:
Mole of anhydrous sodium acetate = 
= 
= 0.18 mole
100 ml of 0.2 molar acetic acid means
= M x V
= 0.2 x 100
= 20 mmol
= 0.02 mole
Using Henderson equation to find pH of Buffer solution
pH = pKa + log![\frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
= 4.74 + log
= 4.74 + log 9
= 5.69
So pH of the Buffer solution = 5.69
The original mass of krypton 81 that is present in the ice is 6.70 grams.
<h3>How do we calculate original mass?</h3>
Original mass of any substance will be calculated as below for the decomposition reaction is:
N = N₀(1/2)ⁿ, where
N = remaining mass of krypton-81 = 1.675g
N₀ = original mass of krypton-81 = ?
n will be calculated as:
n = T/t, where
T = total time period = 458,000 years
t = half life time = 229,000 years
n = 458,000/229,000 = 2
Now putting all these values on the above equation, we get
N₀ = 1.675 / (1/2)²
N₀ = 6.70 g
Hence required mass is 6.70 g.
To know more about half life time, visit the below link:
brainly.com/question/2320811
Answer:
C.
Explanation:
A chemical change happens when one chemical substance is transformed into one or more different substances, such as when iron becomes rust.
First cell theory. All living things are composed of cells.
Second cell theory. Cells are the basic unit of structure and function in living things.
Third cell theory. All cells are produced from other cells
This definition would best fit conformational isomers. Two compounds that have different structural formulas, although the number and types of atoms are the same.
