Answer:
1) K and Rb
2) 20 protons, 20 neutrons, and 20 electrons.
Explanation:
1) If it's in the same column, it has the same # of valence electrons (e- on the outer shell), therefore similar chemical properties.
2)
1) atomic #, 20, is the number of protons
2) subtract the mass number from # of protons, which you get 20 neutrons
3) Number of electrons in a neutral atom = number of electrons, which is 20. You can also check yourself by looking at electron configuration on a full periodic table.
it's 0.2cm different from the expected value, wich was 14.6cm
how many percent that are is calculated in the screenshot.
rounded it's 1.37%
Answer:
Excess reactant - Reactant that can produce more of the product
Limiting reactant - Reactant that can produce a lesser amount of the product
Theoretical yield - Amount of product predicted to be produced by the given reactants
Explanation:
In every chemical reaction, there is a limiting reactant and there is an excess reactant.
The limiting reactant determines the amount of product obtained. It is the reactant that produces a lesser amount of the product.
The excess reactant is known to be the reactant that produces a greater amount of the product.
The theoretical yield is calculated using the limiting reactant and is the amount of product predicted to be produced by the given reactants.
Answer:
6
Explanation:
Normally, oxygen has 8 electrons and 8 protons. If the charge is 2-, then that means there are two more protons than electrons. There would be 6 electrons.
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 ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
If you know pH and pka:
10^(pH-pka) = ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
The ratio will be: 10^(pH-pka)
- At pH = pKa for an acid, [conjugate base] = [acid] in solution. <em>TRUE</em>
pH = pka + log₁₀ ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
0 = log₁₀ ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
10^0 = ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
1 = ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
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 ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
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 ![\frac{[A^-]}{[HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
If pH << pKa, 10^(pH-pka) will be << 1, that means that you have more [HA] than [A⁻]
I hope it helps!