Covalent bond is a type of chemical bond which is formed as a result of sharing of electron pairs among the elements that are involved. The structure of the covalent bond is affected by the electronegativity of the elements involved. The molecules joined by covalent bond range in size from very small to very large polymers. There are different types of structures for covalent substances, these include: macromolecular substances, molecular substances and giant covalent structures. Strong bonds hold individual molecules together but there are negligible forces of attraction among them.
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Answer:
Hope it helped
Explanation:
For neutral atoms, the number of valence electrons is equal to the atom's main group number. The main group number for an element can be found from its column on the periodic table. For example, carbon is in group 4 and has 4 valence electrons. Oxygen is in group 6 and has 6 valence electrons.
First, lets balance the reaction equation:
4Fe + 3O₂ → 2Fe₂O₃
It is visible form the equation that 4 moles of Fe require 3 moles of O₂
Molar ratio Fe/O₂ = 4/3 = 1.33
Molar ratio O₂/Fe = 3/4 = 0.75
Now, we check the molar ratios present:
Fe/O₂ = 6.8/8.9 = 0.76
O₂/Fe = 1.31
Thus, Iron is the limiting reactant because its ratio is not being fulfilled while the ratio of O₂ is surpassed.
Answer:
1, 2, and 3 are true.
Explanation:
The Henderson-Hasselbalch equation is:
pH = pka + log₁₀ ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
- If the pH of the solution is known as is the pKa for the acid, the ratio of conjugate base to acid can be determined. <em>TRUE</em>
pH = pka + log₁₀
If you know pH and pka:
10^(pH-pka) =
The ratio will be: 10^(pH-pka)
- At pH = pKa for an acid, [conjugate base] = [acid] in solution. <em>TRUE</em>
pH = pka + log₁₀
0 = log₁₀
10^0 =
1 =
As ratio is 1, [conjugate base] = [acid] in solution.
- At pH >> pKa for an acid, the acid will be mostly ionized. <em>TRUE</em>
pH = pka + log₁₀
If pH >> pKa, 10^(pH-pka) will be >> 1, that means that you have more [A⁻] than [HA]
- At pH << pKa for an acid, the acid will be mostly ionized. <em>FALSE</em>
pH = pka + log₁₀
If pH << pKa, 10^(pH-pka) will be << 1, that means that you have more [HA] than [A⁻]
I hope it helps!
