Answer:
The answer to your question is 0.22
Explanation:
Data
Acetonitrile (CH₃CN) density = 0.786 g/ml
Methanol (CH₃OH) density = 0.791 g/ml
Volume of CH₃OH = 22 ml
Volume of CH₃CN = 98.4 ml
Process
1.- Calculate the mass of Acetonitrile and the mass of Methanol
density = mass/ volume
mass = density x volume
Acetonitrile
mass = 0.786 x 98.4
= 77.34 g
Methanol
mass = 0.791 x 22
= 17.40 g
2.- Calculate the moles of the reactants
Acetonitrile molar mass = (12 x 2) + (14 x 1) + (3 x 1)
= 24 + 14 + 3
= 41 g
Methanol molar mass = (12 x 1) + (4 x 1) + (16 x 1)
= 12 + 4 + 16
= 32 g
Moles of Acetonitrile
41 g ----------------- 1 mol
77.34g ------------ x
x = (77.34 x 1) / 41
x = 1.89 moles
Moles of Methanol
32 g -------------- 1 mol
17.40 g --------- x
x = (17.40 x 1)/32
x = 0.54 moles
3.- Calculate the mole fraction of Methanol
Total number of moles = 1.89 + 0.54
= 2.43
Mole fraction = moles of Methanol / total number of moles
Mole fraction = 0.54/ 2.43
Mole fraction = 0.22
Answer:
2. (C) K⁺; 3. (E) Hg⁺; 4. Hg⁺
Explanation:
We must first write the electron configurations of the different species.
(A) Fe²⁺
Fe: [Ar]4s²3d⁶
Fe²⁺: [Ar]3d⁶
When removing electrons from a transition metal ion, you remove the s electrons first.
(B) Cl
Cl: [Ne]3s²3p⁵
(C) K⁺
K: [Ar]4s
K⁺: [Ar]
(D) Cs
Cs: [Xe]6s
(E) Hg⁺
Hg: [Xe]6s²4f¹⁴5d¹⁰
Hg⁺: [Xe]6s4f¹⁴5d¹⁰
2. K⁺ has a noble gas configuration
3. Hg⁺ has electrons in f orbitals.
4. The electron configuration of Au is [Xe]6s4f¹⁴5d¹⁰, not [Xe]6s²4f¹⁴5d⁹, because a filled d subshell is more stable than a filled s subshell.
Thus, Hg⁺ is isoelectronic with Au.
A dilute acid solution is prepared by adding the concentrated acid to water. If you do the reverse, i.e. add water to the acid it is possible that a small amount water could react with acid and boil and explode thus splashing the acid onto you or someone else near the activity.
Answer:
A) 12 mol H2O.
Explanation:
Hello,
In this case, for the given reaction:
We notice that oxygen is in a 7:6 molar relationship with water, for that reason, the resulting moles of water turn out:
Thus, the answer is A) 12 mol H2O.
Best regards.
Answer:
The answer to your question is pH = 9.2; [OH] = 1.58 x 10⁻⁵
Explanation:
Data
[H⁺] = 6.0 x 10⁻¹⁰ M
pH = ?
pH definition. pH measures the hydrogen concentration. pH measures the acidity and the alkalinity of a solution. A solution is acid if the pH goes from 0 to 6.9, a neutral solution has a pH of 7 and an alkali solution has a pH from 7.1 to 14.
pOH measures the [OH⁻] concentration
Formula
pH = -log[H⁺]
pH + pOH = 14
-Substitution
pH = -log[6 x 10⁻¹⁰]
-Simplification
pH = - (-9.2)
pH = 9.2
-Calculate pOH
pOH = 14 - pH
pOH = 14 - 9.2
pOH = 4.8
-Calculate the concentration of OH⁻
pOH = -log[OH⁻]
[OH⁻] = -antilog4.8
[OH] = 1.58 x 10⁻⁵
