Answer:
pH = 4.71
Explanation:
We can find the pH of a buffer (Mixture of weak acid: CH3COOH, and its conjugate base: CH3COONa) using H-H equation:
pH = pKa + log [CH3COONa] / [CH3COOH]
Where pH is the pH of the buffere = 4.74, pKa the pka of the buffer and [] could be taken as the moles of each reactant.
As initially [CH3COONa] = [CH3COOH], [CH3COONa] / [CH3COOH] = 1:
pH = pKa + log 1
4.74 = pKa
To solve this question we need to find the initial moles of each species, The CH3COONa reacts with HCl to produce CH3COOH. That means the moles of CH3COOH after the reaction are: Initial CH3COOH + Moles HCl
Moles CH3COONa: Initial CH3COONa - Moles HCl.
Moles CH3COOH:
0.100L * (0.50mol / L) = 0.050 moles CH3COOH + 0.0020 moles HCl =
0.052 moles CH3COOH
Moles CH3COONa:
0.100L * (0.50mol / L) = 0.050 moles CH3COONa - 0.0020 moles HCl =
0.048 moles CH3COONa
Using H-H equation:
pH = 4.74 + log [0.048 moles] / [0.052 moles]
pH = 4.71The pH be after 0.0020 mol of HCl has been added to 100.0 mL of the buffer is 4.71.
What is buffer solution?Buffer solution is a mixture of weak acid and its conjugate base or vice versa.
We can calculate the pH of buffer solution by using Henderson - Hasselbalch Equation:
pH = pKa + log[CH₃COONa] / [CH₃COOH]
Initially concentration of CH₃COONa is equal to the concentration of CH₃COOH and equal becomes:
4.74 = pKa + log(1)
pKa = 4.74
Given moles of added HCl moles = 0.002 mole
Given molarity of each CH₃COOH & CH₃COONa = 0.50M
Given Volume = 100mL
We can calculate the moles by using the formula:
n = M × V
Moles of CH₃COOH & CH₃COONa = 0.100 × 0.50 = 0.050 moles
Moles of CH₃COOH = 0.050moles CH₃COOH + 0.0020moles HCl =
0.052moles CH₃COOH
Moles of CH₃COONa = 0.050moles CH3COONa - 0.0020moles HCl =
0.048moles CH₃COONa
Now, resultant pH will be:
pH = 4.74 + log [0.048 moles] / [0.052 moles]
pH = 4.71
Hence, pH of resultant solution is 4.71.
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Calculate the molality of a solution containing 22.75 g of glycerol (C3H8O3) in 79.6 g of ethanol (C2H5OH).
Answer:
3.11 mol/kg
Explanation:
Molality M = number of moles of solute, n/mass of solvent, m
To calculate the number of moles of glycerol (C₃H₈O₃) in 22.75 g of glycerol, we find its molar (molecular) mass, M',
So, M' = 3 × atomic mass of carbon + 8 × atomic mass hydrogen + 3 × atomic mass of oxygen
= 3 × 12 g/mol + 8 × 1 g/mol + 3 × 16 g/mol = 36 g/mol + 8 g/mol + 48 g/mol = 92 g/mol.
So, number of moles of glycerol, n = m'/M' where m' = mass of glycerol = 22.75 g and M' = molecular mass of glycerol = 92 g/mol
So, n = m'/M'
n = 22.75 g/92 g/mol
n = 0.247 mol
So, the molality of the solution M = n/m
Since m = mass of ethanol = 79.6 g = 0.0796 kg, substituting the value of n into the equation, we have
M = 0.247 mol/0.0796 kg
M = 3.11 mol/kg
So, the molality of the solution is 3.11 mol/kg.
Use the heating curve of 60.0 grams of ice and the list of values to answer the question.
A heating curve with the y -axis showing temperatures between -20 degrees Celsius and 15 degrees Celsius and the x-axis showing time. The plot starts at Point A at -20 degrees Celsius and moves diagonally upward and to the right until it reaches Point B, which measures 0 degrees Celsius. Next, the line runs horizontally to the right until it reaches Point C. From Point C the line moves up and to the right to Point D, which measures at 15 degrees Celsius.
© 2019 StrongMind
specific heat of ice = 2.10 J/(g·°C)
specific heat of water = 4.18 J/(g·°C)
specific heat of water vapor = 2.07 J/(g·°C)
latent heat of fusion of ice = 333.4 J/g
latent heat of vaporization of water = 2256 J/g
How much energy was added to the ice between Point A and Point D?
25 kJ
150 J
154 J
26 kJ
Answer:
Changes of state occur at segment
✔ B–C
and segment
✔ D–E
Explanation:
got it right on edge :)
The amount of energy added to the ice between Point A and Point D is approximately 25 kJ.
To calculate the amount of energy added to the ice between Point A and Point D, we need to consider the different stages of the heating curve.
Heating the ice from -20°C to 0°C:
The energy required to raise the temperature of the ice can be calculated using the specific heat of ice (2.10 J/(g·°C)) and the mass of the ice (60.0 g). The temperature change is from -20°C to 0°C, which is a total of 20 degrees.
Energy = mass × specific heat × temperature change
Energy = 60.0 g × 2.10 J/(g·°C) × 20°C
Energy = 2520 J
Melting the ice at 0°C:
The energy required to melt the ice can be calculated using the latent heat of fusion of ice (333.4 J/g) and the mass of the ice (60.0 g).
Energy = mass × latent heat of fusion
Energy = 60.0 g × 333.4 J/g
Energy = 20,004 J
Heating the water from 0°C to 15°C:
The energy required to raise the temperature of the water can be calculated using the specific heat of water (4.18 J/(g·°C)) and the mass of the water (60.0 g). The temperature change is from 0°C to 15°C, which is a total of 15 degrees.
Energy = mass × specific heat × temperature change
Energy = 60.0 g × 4.18 J/(g·°C) × 15°C
Energy = 3753 J
The total energy added to the ice between Point A and Point D is the sum of the energy calculated in each step:
Total Energy = Energy (Heating ice) + Energy (Melting ice) + Energy (Heating water)
Total Energy = 2520 J + 20,004 J + 3753 J
Total Energy = 25,277 J
Converting this energy to kilojoules (kJ):
Total Energy = 25,277 J ÷ 1000
Total Energy = 25.277 kJ
Therefore, the amount of energy added to the ice between Point A and Point D is approximately 25 kJ.
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6. Which compound contains no ionic character?
Answer:
The compound which doesn't contains ionic character is HC, H-atom and CL- atom shares 1 electron a to form covalent bond....
Would 1 pound of peanut butter occupy more or less space than 1 pound of water?
Write a balanced chemical equation for the reaction of aqueous potassium hydroxide with aqueous iron(III) chloride to form solid iron(III) hydroxide and aqueous potassium chloride. Express your answer as a chemical equation including phases. nothing A chemical reaction does not occur for this question.
Answer:
3KOH(aq) + FeCl3(aq) --------> Fe(OH)3 + 3KCl
Explanation:
The rule for balancing chemical equations is that the number of atoms of each element must be the same on both sides of the reaction equation.
Hence, the two reactants are potassium hydroxide and aqueous iron(III) chloride.
The balanced molecular reaction equation is;
3KOH(aq) + FeCl3(aq) --------> Fe(OH)3 + 3KCl
How many liters of hydrogen can be produced at a pressure of 2 atm and a temperature of 298 K
Answer:
1.17 L of H₂
Explanation:
We'll begin by calculating the number of mole in 2.3 g of Mg. This can be obtained as follow:
Mass of Mg = 2.3 g
Molar mass of Mg = 24 g/mol
Mole of Mg =?
Mole = mass /molar mass
Mole of Mg = 2.3 / 24
Mole of Mg = 0.096 mole
Next, we shall determine the number of mole of H₂ produced by the reaction of 2.3 g (i.e 0.096 mole) of Mg. This can be obtained as follow:
Mg + 2HCl —> MgCl₂ + H₂
From the balanced equation above,
1 mole of Mg reacted to 1 mole of H₂.
Therefore, 0.096 mole of Mg will also react to produce 0.096 mole of H₂.
Finally, we shall determine volume of H₂ produced from the reaction. This can be obtained as follow:
Number of mole (n) of H₂ = 0.096 mole
Pressure (P) = 2 atm
Temperature (T) = 298 K
Gas constant (R) = 0.0821 atm.L/Kmol
Volume (V) of H₂ =?
PV = nRT
2 × V = 0.096 × 0.0821 × 298
Divide both side by 2
V = (0.096 × 0.0821 × 298) /2
V = 1.17 L
Therefore, 1.17 L of H₂ were obtained from the reaction.
Determine whether each phrase describes carboxylic acids or esters.
a. Usually have a sour odor _____________
b. Notable for their pleasant fragrances ___________
c. Do not form hydrogen bonds amongst themselves and have higher vapor pressure _____________
d. Their reactions with base are known as neutralizations ____________
e. Their reactions with base are known as saponifications _____________
Rock, metal, wood, glass, animals, and plants are all forms of what?
viagnesiumi anu
If I have 100g of Magnesium, how much Magnesium Nitride will I theoretically create?
O 24.3g Mg3 N2
O 138.4g Mg3 N2
415.2g Mg3 N2
O 200g Mg3 N2
Answer:
Theoretical yield is 138.4 g
Explanation:
In the first step we determine the reaction:
3Mg + N₂ → Mg₃N₂
Mass of reactant is 100 g. We assume the nitrogen is in excess, so we work with Mg. We convert mass to moles:
100 g . 1mol/ 24.3g = 4.11 moles of Mg.
Ratio is 3:1. 3 moles of Mg can produce 1 mol of nitride
Our 4.11 moles, may produce (4.11 . 1)/3 = 1.37 moles of Mg₃N₂
We convert mass to moles, to find the theoretical yield:
1.37 mol . 100.9 g/mol = 138.2 g
Calculate the number of ATOMS in 1.0 mole of O2. blank x 1024
Answer:
6.023*10^23........ .......
There is a type of algae that lives in the cells of corals. These algae process carbon through photosynthesis and pass it on to corals in the form of glucose, a sugar that provides the energy corals need to survive and function. Corals offer protection for the algae and also produce wastes that the algae need for photosynthesis.
Warmer water temperatures caused by global warming disrupt photosynthesis in the algae, causing a poisonous build-up that threatens corals. This causes corals to force the algae out of their cells.
Answer:
Explanation:
Sample Response: If global warming continues, corals will continue to expel the algae from their cells to avoid poisonous buildup. This will cause corals to die. Without corals, the algae are not protected and cannot perform photosynthesis. This will cause the algae to die as well.
Q2.Which is true about potassium?
Extremely unreactive
Not very reactive
Slightly reactive
Very reactive
A solution of the ionic salt NaF
would have _____
pH.
A. An acidic
B. A basic
C. A neutral
Answer:
The answer is basic
Explanation:
Choose letter b or basic. You welcome.
The strong acid and strong base has high rate constant of dissociation. The rate constant for weak acid and base for the dissociation is low, they do not easily dissociate in water. Therefore option B is the correct option.
What are acid and base?Acid is a solution which releases H⁺ hydrogen ion when dissolved in water. Base releases hydroxide ion OH⁻ ion when dissolved in water.
pH is a measurement of amount of hydronium ion H₃O⁺ in a given sample. Strength of acidic nature is directly proportional to the concentration of hydronium ion.
On subtracting pH from 14, we get pOH which measures the concentration of hydroxide ion in a given solution. Temperature affect the pH. At room temperature pH scale is between 0 to 14. 7 is the pH of neutral solution. A solution of the ionic salt NaF is basic in nature.
Therefore, option B is the correct option.
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If I have 25g of Sodium, how much Sodium Chloride will I theoretically create?
O 50g NaCl
0 58.3g NaCl
O 63.7g Naci
0 35.4g NaCl
Answer:
64 g
Explanation:
Step 1: Write the balanced equation
2 Na + Cl₂ ⇒ 2 NaCl
Step 2: Calculate the moles corresponding to 25 g of Na
The molar mass of Na is 22.98 g/mol.
25 g × 1 mol/22.98 g = 1.1 mol
Step 3: Calculate the moles of NaCl formed from 1.1 moles of Na
The molar ratio of Na to NaCl is 2:2. The moles of NaCl formed are 2/2 × 1.1 mol = 1.1 mol.
Step 4: Calculate the mass corresponding to 1.1 moles of NaCl
The molar mass of NaCl is 58.44 g/mol.
1.1 mol × 58.44 g/mol = 64 g
What are the equipments needed to determine the density of a liquid in laboratory ?
Answer:
A hydrometer is a special device used to determine the density of liquids.
Explanation:
I hope this helps you. Have a nice day!
In the experiment "Preparation and Standardization of a Sodium Hydroxide Solution", why was the burette rinsed with NaOH before filling it to "zero" for the titration?
Answer: The correct option is ALL OF THE ABOVE.
Explanation:
TITRATION is a type of volumetric analysis which is used for determining the concentration of solutions. In this process a specific volume of a solution is placed in a conical flask by means of a pipette and small quantities of a second solution is slowly added from a burette until the end point is reached. This is determined by a means of an indicator which shows a characteristic colour change.
During titration, the following precautions should be followed to avoid errors and maintain standardisation in the experiment.
--> Any air bubble in the burette and pipette must be removed during measurement
--> the burette tap should be tightened to avoid leakage.
--> Remove the funnel from the burette before taking any reading to avoid errors in reading the volume.
--> use the base solution such as Sodium Hydroxide Solution to rinse the burette after washing with soap and tap water:
• to remove any air bubble and fill it's tip
• to remove any residual liquid from the water and soap solution which may interfere with the results of the experiment.
• to check if the burette is in good condition.
Therefore all of the above options to the question are correct.
Plz help me ASAP in my final project I am ready to pay 20$
Answer:
what do you need help with
A 1.19 g sample of an unknown halogen occupies 109 mL at 398 K and 1.41 atm. What is the identity of the halogen
Answer:
The halogen is Iodine.
Explanation:
Using the ideal gas equation, we find the number of moles of gas present, n.
PV = nRT where P = pressure of gas = 1.41 atm, V = volume of gas = 109 mL = 0.109 L, n = number of moles of gas, R = molar gas constant = 0.082 L-atm/mol-K and T = temperature of gas = 398 K
Since PV = nRT, making n subject of the formula, we have
n = PV/RT
substituting the values of the variables into the equation, we have
n = 1.41 atm × 0.109 L/(0.082 L-atm/mol-K × 398 K)
n = 0.15369 atm-L/32.636 L-atm/mol
n = 0.0047 mol
Since n = m/M where m = mass of gas = 1.19 g and M = relative molecular mass of gas
So, M = m/n
M = 1.19 g/0.0047 mol
M = 252.7 g
Since halogens are diatomic the relative atomic mass is M/2 = 252.7g/2 = 126.34 g
From tables, the only halogen with this atomic mass is Iodine.
So, the halogen is Iodine.
Acetoacetyl-ACP is formed as an intermediate during fatty acid biosynthesis. The CO2 used to synthesize malonyl-CoA is lost. Would this help make the reaction more or less energetically favorable
Answer:
This would make the reaction more energetically favourable
Explanation:
Fatty acid synthesis starts with the carboxylation of acetyl CoA to malonyl CoA. This irreversible reaction is the committed step in fatty acid synthesis. The synthesis of malonyl CoA is catalyzed by acetyl CoA carboxylase, which contains a biotin prosthetic group.
What is different between margerine and butter in term of organic chemistry
Answer:
The most important difference between the two is that butter is derived from dairy and is rich in saturated fats, whereas margarine is made from plant oils. ... If the margarine contains partially hydrogenated oils, it will contain trans fat, even if the label claims that it has 0 g.
Explanation:
(⌒_⌒;)
Define mass number of an atom.
following this list of common polyatomic ions what would be the charge for aluminum nitrate?
Nitrate NO3
Phosphate PO43,
Sulfate SO4 -2
acetate C2H3O2-1
Ammonium NH4.
Chromate CrO4-2
Carbonate C03-2
Dichromate CrO7-2
Permanganate MnO4-1
What would be the correct answer for Aluminum nitrate
Answer:
Nitrate NO3
here's your answer, hope it helps you
Which of the following two periods contain the same number of element?
A. 2 & 3
B.3 & 4
c. 4 & 6
D. 2 & 4
Answer:
4 and 6
Explanation:
Period 4 has 18 elements and so does period 6.
What is the law of multiple proportions?
A. The proportion of elements to compounds is constant.
B. All elements are found in equal proportions in nature.
C. Different compounds may contain the same elements but may have different ratios of those elements.
D. All compounds contain the same elements in the same proportions.
Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients.
P4(s) + NaOH(aq) + H2O(l) -> Ph3(g) + Na2HPO3(aq)
Answer:
I used a,b c, d in the equation as substituted coefficients to find the unknown for each element of P, Na, O, H, and I got
P4(s) + 4NaOH(aq) + 2H20(l)---->2Ph3 +2Na2HPO3(aq).
which I think should be the answer.
Using the following reaction:
H2SO4 (aq) + 2NaOH (aq) → Na2SO4 (aq) + 2H2O (l)
Calculate the molarity of the H2SO4 solution if 14.92 mL of NaOH was necessary to reach the endpoint of a titration. The molarity of the NaOH solution was 0.83 M and 25.18 mL of H2SO4 was added to the Erlenmeyer flask.
Answer:
The molar concentration of the H₂SO₄ solution is 0.28 M
Explanation:
Molar concentration = number of moles / volume in litres
Number of moles = molar concentration × volume
From the equation of reaction, molar ratio of acid to base = 1 : 2
Using the formula; Na/Nb = CaVa/CbVb
Where Na is the number of moles of acid; Nb = number of moles of base; Ca = concentration of acid; Va = volume of acid; Cb = concentration of base; Vb = volume of base; Na/Nb = mole ratio of acid to base
Substituting the given values in the equation:
1/2 = Ca × 25.18 / 0.93 × 14.92
Ca = 0.93 × 14.92/ 25.18 × 2
Ca = 0.28M
Therefore, the molar concentration of the H₂SO₄ solution is 0.28 M
What are the concentrations of hydronium and hydroxide ions in a solution with pH 2.6?
Please help omg. Ive been stuck for 15 minutes
Answer:
The concentrations of hydronium and hydroxide ions in a solution with pH 2.6 are 2.51*10⁻³ and 3.98*10⁻¹² respectively.
Explanation:
pH is a measure of the acidity or alkalinity of an aqueous solution. The pH indicates the concentration of hydrogen ions present in certain solutions. Mathematically it is defined as the opposite of the base 10 logarithm or the negative logarithm of the activity of hydrogen ions, whose equation is
pH= -log [H⁺]
So, being pH= 2.6 and replacing in the definition of pH:
2.6= -log [H⁺]
[tex][H^{+} ]=10^{-2.6}[/tex]
[H⁺]=2.51*10⁻³
pOH is a measure of the concentration of hydroxide ions (OH⁻). The sum between the pOH and the pH results in 14:
pOH + pH= 14
So, being pH= 2.6:
pOH + 2.6= 14
pOH= 14 - 2.6
pOH= 11.4
The pOH is defined as the negative logarithm of the activity of the hydroxide ions. That is, the concentration of OH⁻ ions:
pOH= - log [OH⁻]
Being pOH= 11.4 and replacing
11.4= -log [OH⁻]
[tex][OH^{-} ]=10^{-11.4}[/tex]
[OH⁻]= 3.98*10⁻¹²
The concentrations of hydronium and hydroxide ions in a solution with pH 2.6 are 2.51*10⁻³ and 3.98*10⁻¹² respectively.
Draw the Lewis structure for BrCl3. What are the approximate bond angles about the central atom?
a. 60°.
b. 90°.
c. 109°.
d. 120°.
e. 180°.
Answer:
Explanation:
BrCl₃ is an interhalogen compound with a hybridization of sp³d. The approximate bond angles can be predicted from the structure (attached below). Although, the lewis structure might be predicted to be trigonal bipyramidal from the structure, it is however a T-shaped geometry because of it's two lone pairs.
Also, from the structure attached, it can be predicted that the approximate bond angles about the central atom is 120° (360 ÷ 3) since each of the three chlorine atoms is equally spaced about the central atom.
The Lewis structure for BrCl₃ is attached to the image below. The bond angles around the central atom, bromine (Br), are 90 degrees between the bromine and each chlorine atom. Therefore, option B is correct.
A Lewis structure, also known as an electron-dot structure or Lewis dot structure is a diagram that represents the valence electrons of an atom or molecule.
Bromine (Br) is in Group 7A and has 7 valence electrons, while each chlorine (Cl) atom in Group 7A also has 7 valence electrons.
Br: 1 atom × 7 valence electrons = 7 valence electrons
Cl: 3 atoms × 7 valence electrons = 21 valence electrons
Total valence electrons = 7 + 21 = 28
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Rank the following chemical species from lowest absolute entropy (So) (1) to highest absolute entropy (5) at 298 K?
a. Al (s)
b. H2O (l)
c. HCN (g)
d. CH3COOH (l)
e. C2H6 (g)
Answer:
Rank the following chemical species from lowest absolute entropy (So) (1) to highest absolute entropy (5) at 298 K?
a. Al (s)
b. H2O (l)
c. HCN (g)
d. CH3COOH (l)
e. C2H6 (g)
Explanation:
Entropy is the measure of the degree of disorderness.
In solids, the entropy is very less compared to liquids and gases.
The entropy order is:
solids<liquids<gases
Among the given substances, water in liquid form has a strong intermolecular H-bond.
So, it has also less entropy.
Next acetic acid.
Between the gases, HCN, and ethane, ethane has more entropy due to very weak intermolecular interactions.
HCN has slight H-bonding in IT.
Hence, the entropy order is:
Al(s) < CH3COOH (l) <H2O(l) < HCN(g) < C2H6(g)
18. Which of the following solutions will have the highest boiling point?
A. 0.50 mol CH20. in 1.0 kg of water
B. 0.50 mol NaCl in 1.0 kg water
C. 0.50 mol HF in 1.0 kg of water
D. 0.50 mol AICI, in 1.0 kg water
Answer:
highest boiling point.
Explanation:
Hello there!
In this case, according to the given information, it turns out necessary for us to recall the definition of colligative properties, more specifically that of boiling point elevation, defined in terms of the temperature change, van't Hoff's factor, molality of the solution and boiling point elevation constant:
[tex]\Delta T_b=i*m*K_b[/tex]
In such a way, since all the given solutions have the same molality and solvent (water), they all have the same m and Kb, for which we focus on the van't Hoff's factor which is 1 for CH2O (nonionizing), 2 for NaCl (Na and Cl ions are released), 2 for HF (H and F ions are released) and 3 for AlCl₃ (one Al and three Cl ions are released).
Therefore, since D. 0.50 mol AICI, in 1.0 kg water has the greatest van't Hoff's factor, we infer it has the highest boiling point.
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