Answer:
Option : KBr + I -> KBr+I
Explanation:
Single-replacement reaction or single displacement reactions are a type of chemical reactions in which a whole compound reacts with an element in such a way that the element takes place of one of the compound's own elements and sets it free.
If we talk about KBr and I displacement reaction is not possible among these because Iodine is less reactive than Bromine that is why it will not react with KBr or replace Br.
KBr + I -> KBr+ I
Potassium Bromide + Iodine -> Potassium bromide + Iodine
Hope it help!
Answer :
YES, The precipitation reaction will occur.
Explanation : When we mix the aqueous solutions of Lead chloride and Ammonium sulfide a reaction will occur which is stated below :
![PbCl_{2} +(NH_{4}) _{2} S ----\ \textgreater \ PbS + 2[ (NH_{4})Cl]](https://tex.z-dn.net/?f=PbCl_%7B2%7D%20%2B%28NH_%7B4%7D%29%20_%7B2%7D%20S%20----%5C%20%5Ctextgreater%20%5C%20%20PbS%20%2B%202%5B%20%28NH_%7B4%7D%29Cl%5D%20)
The major product that is formed is Lead sulfate which is black in colour.
Once the reaction is complete one can observe a black precipitate getting obtained.
The temperature increase is from 19.5 to 100 degrees centigrade or 80.5 degrees centigrade. The calorie increase is 2.50 x 1000 x 0.238902957619 or a total of 597.25 calories. 597.25/80.5 = 7.419 calories per degree centigrade. 7.419/135 grams = 0.0549 calories/gram/degree centigrade. The conversion from kilo joules involves multiplying the calories per joule x 1000 to get the number of calories in one kilo joule and then by the 2.5.
Answer:
The relation between the shielding and effective nuclear charge is given as

where s denote shielding
z_{eff} denote effective nuclear charge
Z - atomic number
Explanation:
shielding is referred to as the repulsion of an outermost electron to the pull of electron from valence shell. Higher the electron in valence shell higher will be the shielding effects.
Effective nuclear charge is the amount of net positive charge that valence electron has.
The relation between the shielding and the effective nuclear charge is given as
wheres denote shielding
z_{eff} denote effective nuclear charge
Z - atomic number
We add up all the various atoms:
C: 55
H: 72
Mg: 1
N: 4
O: 5
55 + 72 + 1 + 4 + 5
= 137
The answer is B.