Tag: properties of s block elements

Questions Related to properties of s block elements

$LiOH$ reacts with $CO {2}$ to form $Li _{2}CO _{3}$ (atomic mass of $Li = 7)$. The amount of $CO _{2}$ (in g) consumed by $1\ g$ of $LiOH$ is closest to ______.

chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

  1. $0.916$

  2. $1.832$

  3. $0.544$

  4. $1.088$

Show answer
Correct Option: A
Explanation:

Balanced chemical equation is:

$2LiOH+C{ O } _{ 2 }\rightarrow { Li } _{ 2 }C{ O } _{ 3 }+{ H } _{ 2 }O$
Molecular weight of each specie is:
$LiOH$=24 g/mol; $C{ O } _{ 2 }$=44 g/mol; ${ Li } _{ 2 }C{ O } _{ 3 }$= 74 g/mol; ${ H } _{ 2 }O$=18 g/mol
From the reaction:
2 mol of $LiOH$ ($24\times2=48\ g$) consumes 1 mol of $CO _2$ (44 g)
Therefore, 1 g of $LiOH$ will consume $\frac { 1 }{ 48 } \times 44\quad g\quad C{ O } _{ 2 }=0.916\ g\ CO _2$
Option A is the correct answer.

Diagonal relationship of elements in due to same:

chemistry the s-block elements (alkali and alkaline earth metals) anomalous properties of lithium group 1 elements: alkali metals properties of s block elements

  1. size

  2. mass number

  3. atomic number

  4. electron affinity

Show answer
Correct Option: A
Explanation:
In addition to horizontal and vertical trends, there is a diagonal relationship between elements such as Li and Mg, Be and Al, B, and Si, that have an adjacent upper left/lower right relative location in the periodic table. 
These pairs of elements have similar size and electronegativity, resulting in similar properties. 

Diagonal relationships occur because of the directions in the trends of various properties as you move across or down the periodic table. Many of the chemical properties of an element are related to the size of the atom. Hence it is because of the same size.