When energy is needed in order for the reaction to happen, then that reaction is known as endotermic. When the reaction has as a result energy then it is exotermic. An example of an endotermic reaction would be photosynthesis, for an exotermic: combustion.
Answer :
(1) The number of valence electrons present in the compound is, 20
(2) The number of bonded electrons present in the compound is, 16
(3) The number of lone pair electrons present in the compound is, 4
(4) The number of single bonds present in the compound is, 8
Explanation :
Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.
In the Lewis-dot structure the valance electrons are shown by 'dot'.
The given molecule is, 
As we know that carbon has '4' valence electrons, hydrogen has '1' valence electrons and oxygen has '6' valence electrons.
Therefore, the total number of valence electrons in = 2(4) + 6(1) + 6 = 20
According to Lewis-dot structure, there are 16 number of bonding electrons and 4 number of non-bonding electrons or lone pair of electrons.
The Lewis-dot structure of is shown below.
Answer:
0.266 moles of Na⁺
Explanation:
First step we dissociate the salt:
Na₃AsO₄ → 3Na⁺ + AsO₄⁻³
From 1 mol of sodium arsenate, we must have 3 moles of sodium cation and 1 mol of arsenate.
We determine the moles of salt:
18.4 g . 1 mol/ 207.89 g = 0.0885 moles of salt.
We apply the followring rule of three:
1 mol of salt has 3 moles of Na⁺
0.0885 moles of salt may have (0.0885 . 3) / 1 = 0.266 moles of Na⁺
Nitrogen and oxygen do not react at ambient temperature. At high temperatures they have endothermic reactions and produces various oxides of nitrogen.
Explanation:
The difference between nitrogen and oxygen is the nitrogen has seven protons and seven electrons surrounding the nucleus. Whereas the oxygen has eight protons and electrons.
The atoms combines with one another to form molecules. The nitrogen is a inert, colorless gas with no smell or taste, its harmless to human beings.
The oxygen and nitrogen are abundant gases in the atmosphere and have similar physical properties. The oxygen (O2) is twice as soluble in water as nitrogen (N2).
Answer:
Common names of ethers simply give the names of the two alkyl groups bonded to oxygen and add the word ether. The current practice is to list the alkyl groups in alphabetical order (t-butyl methyl ether), but older names often list the alkyl groups in increasing order of size (methyl t-butyl ether).
Explanation:
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