Answer:
Only 
gives spontaneous reaction.
Explanation:
A redox reaction will be spontaneous if standard reduction potential (
) of the reaction is positive. Because it leads to negative standard gibbs free energy change (
), which is a thermodynamic condition for spontaneity of a reaction.
Where 
and 
represents standard reduction potential of reduction half cell and standard reduction potential of oxidation half cell.
(1) Oxidation: 
; 
Reduction: 
; 
So, 
Hence this pair will give spontaneous reaction.
(2) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
(3) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
(4) Similarly as above, 
Hence this pair will give non-spontaneous reaction.
The elements of same group are placed in same group as they have similar properties. So Calcium is the element which resembles Mangesium.
Calcium and Magnesium both are alkaline earth metals.
They have similar properties as they have similar outer or valence shell electronic configuration
The general electronic configuration of alkaline earht metal is ns2
The electronic configuration of Mg [atomic number 12] and Ca [atomic number 20] are
![[Ne]3s^{2}](https://tex.z-dn.net/?f=%5BNe%5D3s%5E%7B2%7D)
and ![[Ar]4s^{2}](https://tex.z-dn.net/?f=%5BAr%5D4s%5E%7B2%7D)
respectively.
The normality of the H₂SO₄ that reacted with 25cc of 5 % NaOH solution is 1.1 N.
<h3>What is the molarity of 5% NaOH?</h3>
The molarity of 5% NaOH is 1.32 M
25 cc of NaOH neutralized 30cc of H₂SO₄ solution.
Equation of reaction is given below:
- 2 NaOH + H₂SO₄ ---> Na₂SO₄ + 2 H₂O
Molarity of H₂SO₄ = 1.32 x 1 x 25/(30 x 2) = 0.55 M
- Normality = Molarity × moles of H⁺ ions per mole of acid
moles of H⁺ ions per mole of H₂SO₄ = 2
Normality of H₂SO₄ = 0.55 x 2 = 1.1 N
In conclusion, the normality of an acid is determined from the molarity and the moles of H⁺ ions per mole of acid.
Learn more about normality at: brainly.com/question/22817773
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Electrostatic, meaning the attraction from one's positive nucleus is to the negative electrons of the other atom and vis versa.
Answer:
A
Explanation:
I guess it's a, because nuclear decay is likely to occur when either the mass or atomic number is greater than 83.
