Calculate the ratio of ch3nh2 to ch3nh3cl required to create a buffer with ph = 10.22.

1 answer:

6 0

When the Ka value for CH3NH2 = 2.27 x 10 ^-11

and when we have the Ka value so, we can get Pka from this formula:

Pka = -㏒Ka

∴Pka = -㏒ (2.27 x10^-11)
= 10.6

now, to get the base/acid ratio by using Henderson-Hasselblach equation:

PH = Pka + ㏒[base/acid]

so by substitution:

10.22 = 10.6 + ㏒[base/acid]

∴[base/acid] = 0.417

∴[CH3NH2/CH3NH3Cl] = 0.417

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Please, find attached the figures of both atom Q and atom P corresponding to this question.

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Since it is assumed that the atom is neutral, it has 8 protons: one positive charge of a proton balances one negative charge of an electron. Thus, the atomic number of this atom is 8.

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Zeff is the effective nuclear charge of the atom. It accounts for the net positive charge the valence electrons experience. And may, in a very roughly way, be estimated as the number of protons less the number of electrons in the inner shells. Thus, for this atom, an estimated Z eff = 8 - 2 = 6.

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Again, each black sphere represents an electron

In total this atom has 9 electrons: 2 in the inner shell and 7 in the outermost shell.

Since it is assumed that the atom is neutral, it has 9 protons.

The atomic number of this atom is 9.

Using the same reasoning used for atom Q, this atom is also in the period 2.

Estimated Z eff = 9 - 2 = 7.

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By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of reactant and product participate in the reaction:

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Being the molar mass of each compound: