Answer:
pH = 2.32
Explanation:
H2A + H2O -------> H3O+ + HA-
Ka2 is very less so i am not considering that dissociation.
now Ka = 8.0×10−5
= [H3O+] [HA-] / [H2A]
lets concentration of H3O+ = X then above equation will be
8.0×10−5 = [X] [X] / [0.28 -X]
8.0×10−5 = X2 / [0.28 -X]
X2 + 8.0×10−5 X - 2.24 x 10−5
solve the quardratic equation
X =0.004693 M
pH = -log[H+}
= -log [0.004693]
= 2.3285
≅2.32
pH = 2.32
<span>Fractionation - to expand from my answer to a previous question fractionation can be used to separate out more than one component based on a specific property. You still wanted to use Distillation on the other answer. Fractionation on this one.</span>
Answer:
A
Explanation:
Remember the number of valence electrons represent the group number. As shown in figure, there is only one electron in the valence shell. Therefore, this element belongs to group 1 elements also called as Alkali metals.
Furthermore, the number of electrons in a neutral atom equals number of protons. Hence, there are 11 protons in this element.
Also, number of protons equal atomic number therefore, the atomic number of this element is 11. And, by checking periodic table, the element having atomic number 11 is Sodium (Na).
The reaction is,
H2S + I2 --------------> 2 HI +S
Molar weight of H2S = 34 g per mol
Molar weight of HI =128 g per mol
Molar weight of I2 =254 g per mol
Moles of H2S in 49.2 g = 49.2 /34 mol = 1.447 mol
So according to stoichiometry of the reaction, number of I2 mols needed
= 1.447 mol
The mass of I2 needed = 1.447 mol x 254 g
Mg + Cl₂ -----> MgCl₂
24g 1 mol
24g Mg ---- 1 mol Cl₂
Xg Mg ------ 2 mol Cl₂
X = 2×24
<u>X = 48g Mg</u>
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:)
