Answer:HNO₃ and NO³⁻ would not function as buffer
Explanation:
The buffer solution are usually prepared by using any weak acid (which would partially dissociate) and mixing this weak acid with its own conjugate base or any weak base (which would partially dissociate) and mixing with with its conjugate acid.
A buffer solution is a solution which resists change in pH of the solution.
Since nitric acid is a very strong acid and hence neither nitric acid HNO₃ or its conjugate base NO³⁻ anionb is suitable for the preparation of buffer solution.
HCO³⁻ is a weak acid and hence it can form a buffer solution with its conjugate base CO₃²-. so they can be used to form buffer.
C₂H₅COOH is a weak acid and hence it can also form buffer solution with its conjugate base.
So only HNO₃and NO³⁻ would not be able to form buffer
So option a is the answer.
The dissociation of calcium carbonate, CaCO3, to simpler compounds can be expressed as,
CaCO3 --> CaO + CO2
The precipitate is CaO and its amount is calculated through the difference which will give us the answer of 5.6 g.
Answer:
401.17 K is the minimum temperature at which the reaction will become spontaneous under standard state conditions.
Explanation:
The expression for the standard change in free energy is:
Where,
is the change in the Gibbs free energy.
T is the absolute temperature. (T in kelvins)
is the enthalpy change of the reaction.
is the change in entropy.
Given at:-
Temperature = 25.0 °C
The conversion of T( °C) to T(K) is shown below:
T(K) = T( °C) + 273.15
So,
T₁ = (25.0 + 273.15) K = 298.15 K
= 128.9 kJ/mol
= 33.1 kJ/mol
Applying in the above equation, we get as:-

= 0.32131 kJ/Kmol
So, For reaction to be spontaneous, 
Thus, For minimum temperature:-

<u>Hence, 401.17 K is the minimum temperature at which the reaction will become spontaneous under standard state conditions.</u>
Answer:
a. Sn or Si ⇒ Sn
b. Br or Ga ⇒ Ga
c. Sn or Bi ⇒ similar in size
d. Se or Sn ⇒ Sn
Explanation:
The larger atom has a larger atomic radius. We have to consider how varies the atomic radius for chemical elements in the Periodic Table. In a group (column), the atomic radius increases from top to bottom while in a period (file), it increases from right to left.
a. Sn or Si ⇒ Sn
They are in the <u>same group</u>. Sn is on the top, so it has a larger atomic radius.
b. Br or Ga ⇒ Ga
They are in the <u>same period</u>. Ga is located at the left so it has a larger atomic radius.
c. Sn or Bi ⇒ similar
They are not in the same group neither the same period. Bi is located more at the bottom, so it would be larger than Sn, but Bi is also at the right side, so it would be smaller than Bi. Thus, they have comparable sizes.
d. Se or Sn⇒ Sn
They are not in the same group neither the same period. Se is located at the top and right side compared to Sn, so Sn is the larger atom.