Answer:
Resonance structures for the nitrate ion exist because there are more than one Lewis Structures for this ion.
Explanation:
How many bonds in each nitrate ion?
To answer this question, start by considering how many electrons each atom need for an octet.
- Each N atom needs three electrons to achieve an octet.
- Each O atom need two electrons to achieve an octet.
The three O atoms and one N atom in each nitrate ion will need electrons in total to be stable. However, the ion carries a charge of . In other words, atoms in the ion have already acquired one extra electron. Now they need only electrons.
Atoms share electrons by forming bonds. In effect, each chemical bond (a pair of shared electrons) adds two electrons to the bonding atoms. Atoms in the nitrate ion will form chemical bonds.
However, there are only three bonding position available. One of the three positions will see a double bond while each of the other two will see a single bond. However, the double bond can be at any of the three bonding position. There are thus three possible Lewis Structures. See the sketched. Note that the three structures are interconvertible by moving only the electrons but not any atoms. Hence the name resonance structures.
Keep in mind that in reality, the pi electrons from the double bond are delocalized across all three possible bonding positions. All three N-O bonds are of equal length.
Answer:
C
Explanation:
Think of 'exo' as exit and 'thermic' as relating to thermal energy/ heat. Thus, an exothermic release thermal energy as the reaction proceeds.
In an exothermic reaction, the total energy of the products is lesser than that of the reactants and ΔH (change in energy) is less than zero.
When heat is absorbed as the reaction proceeds, the chemical reaction is an endothermic reaction.
The reaction:
2 H 2 + O 2 → 2 H 2 O
2 Hydrogen molecules react with 1 Oxygen molecule to create 2 molecules of water.
We have to convert 53.8 g of Hydrogen into moles:
53.8 : 2.02 g / moles = 26.63 moles
2 moles H 2 ↔ 1 mole O 2
26.63 moles H 2 ↔ 13.32 moles O 2
Mass ( O 2 ) = 13.32 moles · 32 g/moles = 426.2 g
Answer: 426.2 grams of Oxygen.
Answer:
4
Explanation:
water starts to boil into water vapor at 100'C. at this point, temperature becomes costant at 100'C as heat energy is used up by the particles to overcome the intermolecular forces between the molecules.
once the forces holding the particles together have been overcome, the temperature will start to rise again showing that all the liquid water has been converted into water vapor