Answer:The 2nd and 3rd one.
Explanation:
It has the same number of protons but different amount of nuetrons.
Answer:
weak acid
Explanation:
pH scale is from 0 to 14
pH =7 is for water which is neutral. it is neither acidic or basic as the hydrogen ion concentration is equal to hydroxyl ion concentration.
Lesser the pH value than 7 greater the acidic nature. And greater the pH value than 7 more the basic nature.
Given pH=3-7 So the indicated interval represents weakly acidic.
Answer:
It is reactive because it has to gain an electron to have a full outermost energy level.
Explanation:
The electron configuration of oxygen is 1s2,2s2 2p4.
Oxygen is in group six in the periodic table so it has six electrons in its valence shell. This means that it needs to gain two electrons to obey the octet rule and have a full outer shell of electrons (eight).
Answer:
6.68 X 10^-11
Explanation:
From the second Ka, you can calculate pKa = -log (Ka2) = 6.187
The pH at the second equivalence point (8.181) will be the average of pKa2 and pKa3. So,
8.181 = (6.187 + pKa3) / 2
Solving gives pKa3 = 10.175, and Ka3 = 10^-pKa3 = 6.68 X 10^-11
Answer : The concentration of solution is, 8.53 M.
Explanation :
As we are given, 45.0 mass % solution of ethanol in water that means 45.0 g of ethanol present in 100 g of solution.
First we have to calculate the volume of solution.


Now we have to calculate the molarity of solution.
Mass of
= 45.0 g
Volume of solution = 114.5 mL
Molar mass of
= 46.07 g/mole
Molarity : It is defined as the number of moles of solute present in one liter of volume of solution.
Formula used :

Now put all the given values in this formula, we get:

Therefore, the concentration of solution is, 8.53 M.