If the item or substance has changed into a state where you are able to change it back such as:
Water melting
Water freezing
Fe3O4 + 4H2 = 3Fe + 4H2O
Fe3O4 + 4H2SO4 = Fe2(SO4)3 + FeSO4 + 4H2O
Answer:
1) correct
2) incorrect
3) correct
4)incorrect
Explanation:
1) A Lewis acid is a substance that accepts a nonbonding pair of electrons.
A Bronsted-Lowry acid is a substance that donates a proton H⁺
Since the donation of a proton involves the acceptance of a pair of electrons, every Bronsted-Lowry acid is also a Lewis acid.
2)A Lewis acid not necessarily needs to have a proton to be donated.
3) Conjugated acids of weak bases are strong acids and conjugated acids of strong bases are weak acids.
4)K⁺ comes from a strong base, therefore is does not have an acidic behaviour.
Electronic configuration of cromium is
Cr-[Ar]4s¹3d⁵
When cromium loses two electrons it becomes Cr⁺².
So its electronic configuration becomes,
Cr⁺²-[Ar]3d⁴
One electron will go from 4s orbital and one electron will go from 3d orbital.
So the answer here is D. [Ar]3d⁴ -because after losing 2 electrons electronic configuration of cromium becomes [Ar] 3d⁴.
I don’t know but look up the ph of ammonia and if it is below 7 then it is yellow and if it is above 7 then blue
