Answer:
4 pairs are needed for the bonds, leaving 1 lone pair. Each double bond uses 2 bond pairs and can be thought of as a single unit. There are 2 double bond units and 1 lone pair, which will try to get as far apart as possible - taking up a trigonal planar arrangement.
The molarity of a solution prepared from 25.0 grams of methanol and 100.0 milliliters of ethanol is approximately 7.80 M.
This is a question about calculating molarity, which is a measure of concentration using moles per liter. To calculate the molarity of a methanol in ethanol, we first have to convert the mass of methanol into moles. The molar mass of methanol (CH3OH) is about 32.04 g/mol. Therefore, 25.0 g of methanol equals about 0.780 moles (25.0 g ÷ 32.04 g/mol).
Next, the volume of ethanol needs to be converted from milliliters to liters. Thus, 100.0 mL becomes 0.100 L. Finally, the molarity is calculated by dividing the moles of methanol by the volume of the ethanol in liters, resulting in a molarity of approximately 7.80 M (0.780 moles ÷ 0.100 L).
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Answer:
D. CH₃CH₂C(CH₃)₂C≡CCH(CH₃)₂
Explanation:
You start numbering from the end closest to the triple bond (on the right). The triple bond is between C3 and C4, and there is one methyl group on C3 and two on C5.
A. CH₃CH₂CH(CH₃)C≡CCH₂CH(CH₃)₂ is wrong. The longest chain has eight C atoms, so the compound is an octyne.
B. CH₃CH₂CH(CH₃)C≡CC(CH₃)₃ is wrong. This is a molecule of 2,2,5-trimethylhept-3-yne.
C. (CH₃CH₂)₂C≡CCH₂CH₃ is wrong. This is a molecule of 6-ethyl-5-methylhept-3-yne.
E. CH₃CH₂CH₂CH(CH₃)C≡CC(CH₃)₃ is wrong. The longest chain has eight C atoms, so the compound is an octyne.
Answer:
Chloroform.
Explanation:
Given,
Solvent requires 1g of compound per 100 mL
For water,
= 1g/47ml
= 2.1
For Chloroform,
= 1 g/8.1 mL
= 12.345679
For Diethyl ether,
= 1 g/370 mL
= 0.27
For Benzene,
= 1 g/86 mL
= 1.2
Partition coefficients:
Water = -
chloroform = 5.9
Diethyl = .13
Benzene = .57
The solvent chloroform would be chosen for drawing out the compound out of an aqueous solution as it has the maximum solubility.
The solubility of a compound in different solvents will determine its concentration in each solvent. The partition coefficient represents the relative solubility of a compound in two immiscible solvents. Chloroform would be the best choice to extract the compound from an aqueous solution.
The solubility of a compound is usually expressed as grams of solute per 100 mL of solvent. To calculate the solubility, you can use the following formula:
Solubility (g/100 mL) = (mass of solute / volume of solvent) * 100
Using this formula, the solubility of the compound in water is 47 g/100 mL, in chloroform is 97.53 g/100 mL, in diethyl ether is 2.70 g/100 mL, and in benzene is 1.16 g/100 mL.
The partition coefficient is a measure of the compound's solubility in two immiscible solvents. To calculate it, divide the solubility of the compound in one solvent by its solubility in another solvent. For example, the partition coefficient between chloroform and water would be:
Partition coefficient = Solubility in chloroform / Solubility in water = 97.53 g/100 mL / 47 g/100 mL = 2.07
The larger the partition coefficient, the more soluble the compound is in the first solvent compared to the second solvent. Based on the partition coefficients, chloroform would be the best choice to extract the compound from an aqueous solution.
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1. _____. the phase change of a substance from the solid state directly to the gaseous state; for example, dry ice, moth balls, or solid air freshener
2. _____. a form of energy transferred (by way of conduction, convection, or radiation) by virtue of a difference in temperature; heat is energy in transit; heat is energy flow, measured in energy units
3. _____. matter with definite volume and definite shape
4. _____. theory in physics based on the fact that particles of matter are in vigorous motion and that the temperature of a substance increases with an increase in either the average kinetic energy of the particles or the average potential energy of separation of the particles, or in both, when heat is added
5. _____. a measure of how hot or cold something is; a measure of the average kinetic energy of the particles of a substance
6. _____. matter with no definite volume or shape
7. _____. the process by which a gas changes phase directly to a solid; for example, the formation of frost
8. _____. a gaslike state of matter consisting of positively charged ions, free electrons, and neutral particles; found in stars, the sun, solar wind, lightning, and fire; unlike gases, plasmas are good conductors of electrical currents
9. _____. net absorption of energy
10. _____. the transfer of heat through matter by way of the collision of molecules
11. _____. heat; energy transferred due to temperature differential that becomes associated with potential energy and kinetic energy on a molecular level
12. _____. the process by which water vapor changes from gas to liquid
13. _____. in a closed system in changing from one form to another, matter and energy cannot be created or destroyed; in this sense, conservation means that the physical quantity of matter and energy is entirely preserved during transformations and reactions
14. _____. physical form of matter, such as solid, liquid, and gas; a distinct state of matter in a system; matter that is identical in chemical composition and physical state, and is separated from other material by the phase boundary; for example, the reaction occurs in the liquid phase of the system
15. _____. the process by which water changes to water vapor
16. _____. net release of energy
17. _____. SI-derived unit to measure energy, work, and quantity of heat; for work, a joule is the amount of work done by a force of 1 N acting through 1 m; also newton-meter
18. _____. matter with definite volume but no definite shape.
WORDS.
1.
condensation
2.
conduction
3.
conservation
4.
depostion
5.
endothermic
6.
evaporation
7.
exothermic
8.
gas
9.
heat
10.
joule
11.
kinetic theory
12.
liquid
13.
phase
14.
plasma
15.
solid
16.
sublimation
17.
temperature
18.
thermal energy
Consider looking up those definitions in a dictionary or in the appendix of your textbook.
Answer is in the Word document.
Answer:
pH at the equivalence point is 8.6
Explanation:
A titulation between a weak acid and a strong base, gives a basic pH at the equivalence point. In the equivalence point, we need to know the volume of base we added, so:
mmoles acid = mmoles of base
60 mL . 0.1935M = 0.2088 M . volume
(60 mL . 0.1935M) /0.2088 M = 55.6 mL of KOH
The neutralization is:
HBz + KOH ⇄ KBz + H₂O
In the equilibrum:
HBz + OH⁻ ⇄ Bz⁻ + H₂O
mmoles of acid are: 11.61 and mmoles of base are: 11.61
So in the equilibrium we have, 11.61 mmoles of benzoate.
[Bz⁻] = 11.61 mmoles / (volume acid + volume base)
[Bz⁻] = 11.61 mmoles / 60 mL + 55.6 mL = 0.100 M
The conjugate strong base reacts:
Bz⁻ + H₂O ⇄ HBz + OH⁻ Kb
0.1 - x x x
(We don't have pKb, but we can calculate it from pKa)
14 - 4.2 = 9.80 → pKb → 10⁻⁹'⁸ = 1.58×10⁻¹⁰ → Kb
Kb = [HBz] . [OH⁻] / [Bz⁻]
Kb = x² / (0.1 - x)
As Kb is so small, we can avoid the quadratic equation
Kb = x² / 0.1 → Kb . 0.1 = x²
√ 1.58×10⁻¹¹ = [OH⁻] = 3.98 ×10⁻⁶ M
From this value, we calculate pOH and afterwards, pH (14 - pOH)
- log [OH⁻] = pOH → - log 3.98 ×10⁻⁶ = 5.4
pH = 8.6
To calculate the pH at equivalence in a titration, we need to consider the concentration of the excess strong base in the solution. First, we calculate the moles of the acid and the base, then we find the moles of the excess base. Using this information, we can find the concentration of the excess base and subsequently calculate pOH. Finally, we can convert pOH to pH using the pH + pOH = 14 relationship.
pH at the equivalence point in a titration can be determined by considering the concentration of the excess strong base present in the reaction mixture. In this case, the excess strong base is KOH. We can calculate [OH-] using the stoichiometry of the reaction and the given concentrations. Then, we can find the pOH using the formula -log[OH-]. Finally, we can convert pOH to pH using the pH + pOH = 14 relationship.
Given:
Step 1: Determine the amount of benzoic acid (HC (H5CO2)) in moles:
moles of HC (H5CO2) = volume (L) × concentration (M) = 0.0600 L × 0.1935 M = 0.01161 mol
Step 2: Determine the amount of KOH in moles:
moles of KOH = volume (L) × concentration (M) = 0.0600 L × 0.2088 M = 0.01253 mol
Step 3: Determine the amount of excess KOH in moles:
moles of excess KOH = moles of KOH - moles required for neutralizing HC (H5CO2) = 0.01253 mol - 0.01161 mol = 9.2 × 10-4 mol
Step 4: Determine the concentration of excess KOH:
concentration of excess KOH = moles of excess KOH / volume (L) = 9.2 × 10-4 mol / 0.0600 L = 0.0153 M
Step 5: Determine the pOH of the solution:
pOH = -log[OH-] = -log(0.0153) ≈ 1.82
Step 6: Determine the pH of the solution:
pH = 14 - pOH = 14 - 1.82 ≈ 12.18
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Answer:
The correct answer is D.
Explanation:
Water can evaporate, and if it does, the density decreases