Explanation:
For a compound to show hydrogen bonding it is necessary that the hydrogen atom of the compound should be attached to more electronegative atom like fluorine, oxygen or nitrogen.
For example, 
, 
and 
all these compounds contain an electronegative atom attached to hydrogen atom.
Therefore, these pure compounds will exhibit hydrogen bonding.
Thus, we can conclude that out of the given options , and are the pure compounds which will exhibit hydrogen bonding.
Answer : The number of moles of 
formed are, 0.69 moles.
Explanation : Given,
Moles of 
= 0.345 mol
Now we have to calculate the moles of
The balanced chemical equation is:
From the balanced reaction, we conclude that
As, 1 mole of react to give 2 moles of
So, 0.345 mole of react to give 
mole of
Therefore, the number of moles of formed are, 0.69 moles.
(159 g Ca/1) x (1 mol Ca/40.07 g Ca) x (6.02*10^23 atoms Ca/1 mol Ca)
= 2.39*10^24 atoms Ca.
Answer: The chemical formula for barium chloride shows the number of ATOMS of each element in the SMALLEST representative unit of the substance.
Explanation:
The chemical formula of compound are ways in which a chemical substance is being expressed using chemical symbols to show types of atoms and subscripts to indicate the number of atoms of each element. It shows the number of atoms in a single ( smallest) representative unit of the substance. Using the compound BaCl2;
"Ba" represents the abbreviation for the element "Barium" while "Cl2" represents the abbreviation for the element "chloride" with the subscript of two indicating the number of atoms of chlorine.
There are steps to be considered while writing a chemical compound of a substance, they include:
--> write the symbol of all the elements that forms the compound ( Ba and Cl).
--> write the valency of each element. (Ba has 2 valence electrons while Cl has 1 valence electron).
--> exchange the valency of the both elements such that Ba bears valency of 1 and Cl bears valency of 2 electrons.
--> finally, write the valency of second atom as subscript of first and Write valency of first atom as subscript of second. You will achieve BaCl2 as your chemical formula.
The answer to your question is climate.
