Answer:
pH = 4.89
0.6171g of KOH must be added
Explanation:
Sodium acetate reacts with HCl producing acetic acid as follows:
NaC2H3O2 + HCl → HC2H3O2 + NaCl
That means the moles added of HCl are moles of acetic acid produced and moles of acetate are initial moles - moles of HCl
Moles HCl = Moles acetic acid:
0.204L * (0.452mol / L) = 0.0822 moles acetic acid.
Initial moles sodium acetate:
0.500L * (0.400mol / L) = 0.200 moles
Moles sodium acetate:
0.200 moles - 0.0822 moles = 0.1172 moles sodium acetate
The pH of this buffer (Mixture of a weak acid and its conjugate base) is obtained using H-H equation:
pH = pKa + log [A-] / [HA]
Where pH is pH of the buffer,
pKa is pKa of the buffer (4.74 for acetic acid)
[A-] Moles of sodium acetate -Conjugate base-
And HA moles of acetic acid -Weak acid-
pH = 4.74 + log [0.1172 moles] [0.0822 moles]
pH = 4.89In 0.500L the moles of the buffer are:
0.500L * (0.200moles / 0.704L) = 0.142 moles of buffer
For a pH of 0.15 units more (4.89 + 0.15 = 5.04):
5.04 = 4.74 + log [Acetate] / [Acetic acid]
0.3 = log [Acetate] / [Acetic acid]
1.9953 = [Acetate] / [Acetic acid] (1)
And as:
0.142 = [Acetate] + [Acetic acid] (2)
Replacing (2) in (1):
1.9953 = 0.142 - [Acetic acid] / [Acetic acid]
1.9953 [Acetic acid] = 0.142 - [Acetic acid]
2.9953 [Acetic acid] = 0.142 moles
[Acetic acid] = 0.0474 moles of acetic acid must remain after the addition of KOH.
In the beginning, moles of acetic acid are:
0.0822 moles * (0.500L / 0.704L) = 0.0584 moles.
That means moles added of KOH (Equal to moles of acetic acid that react) are:
0.0584 moles - 0.0474 moles = 0.0110 moles of KOH
In grams (Molar mass KOH = 56.1g/mol):
0.0110 moles KOH * (56.1g/mol) =
0.6171g of KOH must be addedI NEED HELP ASAP PLEASE I BEG
with what?..................
Which of the following is chemical property?
Question is in the picture help ASAP please
Answer:
C
Explanation:
what processes add methane (CH4) to the atmosphere
Answer:
Cultivated rice paddies
Drilling of natural deposits
Fossil fuel use
Burning of biomass
Landfills
Explanation:
The bulk of the methane released into the atmosphere are as a result of various human activities.
Cultivated rice paddies are a known source of methaneThe drilling of natural deposits and their exploration can release some methane into the atmosphereBurning of fossil fuel and biomass is a source of methane Landfills produces methane as organic materials begins to decay.If you wanted to change the polarity of hydrogen bromide (HBr) by substituting the bromine with a different atom. Which atom would increase the polarity of the molecule?
Answer:
This question is incomplete as it lacks options, the options are:
A. chlorine (CI)
B. iodine (1)
C. sulfur (S)
D. hydrogen (H)
The answer is A. Chlorine
Explanation:
Polarity of a substance in chemistry is a function of electric charges in the atoms of the molecules involved. Polarity, however, can be increased or decreased in molecules depending on the charges of the atoms that form them.
Since polarity increases when an atom in the molecule has a high ability to pull electrons toward itself i.e. electronegativity, one atom that can be substituted for Bromine in the hydrogen bromide (HBr) molecule in order to increase its polarity is CHLORINE. This is because Chlorine (Cl) is more electronegative than Bromine atom, hence, will pull more electrons from hydrogen to make the HCl molecule more polar than HBr.
To increase the polarity of HBr, the bromine atom can be replaced with a hydrogen atom.
A polar molecule is one in which a dipole moment exists. There is a positive end and a negative end in a polar molecule. Conventionally, the direction of the dipole is from the positive end of the molecule towards the negative end of the molecule.
If we want to increase the polarity of the molecule then we must substitute the bromine atom with a more electronegative atom. In this case, chlorine is the best option.
Missing parts;
If you wanted to change the polarity of hydrogen bromide (HBr) by substituting the bromine by a different atom. Which atom would increase the polarity of the molecule?
A. chlorine (CI)
B. iodine (1)
C. sulfur (S)
D. hydrogen (H)
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If a neutral atom has 49 protons, how many electrons does it have?
given that the only known ionic charges of lead are pb(ii) and pb(iv), how can you explain the existence of the pb2o3 salt
Answer:
See Explanation
Explanation:
Pb2O3 is better formulated as PbO.PbO2. It is actually a mixture of the two oxides of lead, lead II oxide and lead IV oxide.
This implies that this compound Pb2O3 (sometimes called lead sesquioxide) is a mixture of the oxides of lead in its two known oxidation states +II and +IV.
Hence Pb2O3 contains PbO and PbO2 units.
Write the condensed electron configurations for the follow- ing atoms and indicate how many unpaired electrons each has: (a) Mg, (b) Ge, (c) Br, (d) V, (e) Y, (f) Lu.
Answer:
i think it is ge
Explanation:
Two or more than two atoms with different physical or chemical properties can not combine together to form an element. Therefore, the condensed electron configurations for the given element can be written as below.
What is element?Element generally consist of atoms or we can atoms combine to form element. Atoms of an element is always same, means all the properties of all atoms of one type of element is same.
The systematic distribution of electrons in the various atomic orbitals is called its electronic configuration. 1,2,3 represents the number of shells and s and represents the orbitals. The superscripts represents the number of electrons in each orbitals.
Electronic configuration of Mg Ne 3s²
Electronic configuration of Ge [Ar] 3d¹⁰ 4s² 4p²
Electronic configuration of Br [Ar] 3d10 4s² 4p⁵
Electronic configuration of V [Ar] 3d³ 4s²
Electronic configuration of Y [ Kr ]4d¹ 5s²
Electronic configuration of Lu [Xe] 4f¹⁴ 5d¹6s²
Therefore, the condensed electron configurations for the given element can be written as above.
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What two options are homogeneous mixture
Answer:
vinegar and soap
Explanation:
Answer:
vinegar and soap
Explanation: just took the test
A student is using colored beads to model 1 molecule of LaTeX: Ca_3\left(PO_4\right)_2C a 3 ( P O 4 ) 2. The student uses blue beads to model Calcium, red beads to model Phosporus, and green beads to model Oxygen. How many of each color will the student need to make their model?
Answer:
3 blue beads
1 red beads
4 green beads
Explanation:
The compound given:
Ca₃PO₄
Elements in the compound are:
Ca
P
O
Number of atoms are :
Ca - 3
P - 1
O - 4
blue beads to model Calcium
red beads to model Phosphorus
green beads to model Oxygen
3 blue beads
1 red beads
4 green beads
What is the mole fraction of water in a solution that contains 8.0 mol of ethanol (C2H5OH) and 1.6 mol of water?
Answer:
the mole fraction of water in a solution is 0.17
Explanation:
The computation of the mole fraction of water in a solution is shown below:
Given that
Ethanol be 8.0 mol
And, the water be 1.6 mol
Based on the above information, the mole fraction of water in a solution is
= Water ÷ (Water + ethanol)
= 1.6 mol ÷ (1.6 mol + 8.0 mol)
= 1.6 mol ÷ 9.6 mol
= 0.17
Hence, the mole fraction of water in a solution is 0.17
For a particular reaction, the change in enthalpy is â9kJmole and the activation energy is 13kJmole. The enthalpy change (ÎH) and activation energy (Ea) for the catalyzed reaction could be which of the following? a. â9kJmole,5kJmole. b. â9kJmole,19kJmole.c. â14kJmole,5kJmole.d. â14kJmole,â13kJmole.
Answer:
The answer is Option a, that is "−9kJmole,5kJmole".
Explanation:
Please find the complete question in the attached file.
In the question, it uses the catalyst inside a process, which does not modify the process eigenvalues, however, it decreases the active energy with an enthalpy of -9kJmole, and also the power for activating decreases around 13 to 5 kJ mole, that's why the choice a is correct.
How many valence electrons are found in P3- ?
Answer:
5 valence elctrons
Explanation:
the outer most orbitals, 3s2 and 3p3 contains 5 electrons, thus valences electrons for P is 5
Is iron man made or natural
Answer:
Iron is natural. Paper is man-made
Explanation:
Answer:
iron
Explanation:
How do hurricanes form? How do hurricanes form?
a Hurricanes form when winds circulate about a column of cool air.
b Hurricanes form when two warm fronts meet over the ocean
c Hurricanes form when warm air over the equator mixes with cold air from the poles
d Hurricanes form as a result of rising warm air and circulating winds
Answer:
D. Hurricanes form as a result of rising warm air and circulating winds
Explanation:
What does this image represent?
Amine group
Carbonyl group
Ether group
Hydroxyl group
Answer:
ether group
Explanation: I looked it up
which type of energy change causes a
leaf to grow
Electromagnetic energy
Explanation:
Growth is one of the characteristics of living things. It refers to the increase of an organism. A leaf is part of a plant, which is a photosynthetic organism i.e. an organism capable of producing its own food using energy from sunlight. Light energy is a part of the ELECTROMAGNETIC ENERGY.
This light energy is used to synthesize glucose (food) via photosynthesis. The glucose, which stores chemical energy in its bond is then broken down to yield ATP used for growth. Hence, the transformation of electromagnetic energy to light energy is how a leaf grow.
If you start with 34.0 grams of silver (I) nitrate, how many grams of solid silver would be
produced?
Answer:
6.36 g AgCl
Hope this helps!
Calculate the volume in milliliters of 1.57 M potassium hydroxide that contains 10.3 g of solute.
Answer:
[tex]V = 0.117 \ L[/tex]
General Formulas and Concepts:
Chem
Reading a Periodic TableWriting compounds and polyatomic ionsMolarity = moles of solute / liters of solutionExplanation:
Step 1: Define
1.57 M KOH (potassium hydroxide)
10.3 g KOH
Step 2: Define conversions
Molar Mass of K - 39.10 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H - 1.01 g/mol
Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol
Step 3: Convert
[tex]10.3 \ g \ KOH(\frac{1 \ mol \ KOH}{56.11 \ g \ KOH} )[/tex] = 0.183568 mol KOH
Step 4: Solve for Volume
Substitute: [tex]1.57 \ M=\frac{0.183568 \ mol}{x \ L}[/tex]Move x: [tex]x1.57 \ M=0.183568 \ mol[/tex]Isolate x: [tex]x=\frac{0.183568 \ mol}{1.57 \ M}[/tex]Evaluate: [tex]x=0.116922 \ L[/tex]Step 5: Check
We are given 3 sig figs. Follow sig fig rules.
[tex]0.116922 \ L \approx 0.117 \ L[/tex]
Ultraviolet light A (UVA) can penetrate deeper layers of skin than UVB. If UVA has a wavelength of 400 nm, how much energy would be in this wave? 2 x 10-17)
Answer:
E = 5×10⁻¹⁹ J
Explanation:
Given data:
Wavelength = 400 nm (400×10⁻⁹ m)
Energy of wave = ?
Solution:
Formula:
E = h c/λ
c = 3×10⁸ m/s
h = 6.63×10⁻³⁴ Js
Now we will put the values in formula.
E = 6.63×10⁻³⁴ Js × 3×10⁸ m/s /400×10⁻⁹ m
E = 19.89×10⁻²⁶ J.m / 400×10⁻⁹ m
E = 0.05×10⁻¹⁷ J
E = 5×10⁻¹⁹ J
An atom of an element has two electrons in the first energy level and five electrons in the second energy level. Write the electron configuration and name the element. How many unpaired electrons does an atom of this element have?
Answer:
electronic configuration: 1s^2,2s^2,2p^3
name: nitrogen
unpaired electron: 3
Explanation:
The atom with 2 electrons and 5 electrons in the first and second energy level is NITROGEN. The element has 3 unpaired electron.
The electronic configuration of the atom is 1s² 2s² 2p³Since the atom has 7 Electrons, the element which has 7 electrons is NITROGEN. The 2p orbital has 3 unpaired electrons in it's second energy level.Therefore, the 2p orbital has 3 unpaired electrons in it's outermost shell.
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Chem Muti Choice. Tell me the correct answer.
Answer:
my gues is red not a 100% but its in the 700s
Explanation:
Which of the compounds of H3PO4, Mg(OH)2, LiOH, and HCl, behave as acids when they are dissolved in water?A. Mg(OH)2 and LiOH.B. B H3PO4 and HC.C. Only HCl.D. Only LiOH.
Answer:
B. H3PO
Explanation:
The pH, texture, reactivity, and conductivity should be seen while determining acid or base. Among given option, H₃PO₄ is the acid when dissolved in water.
What are acid and base?Acid is a substance that has sour taste, pH lies in the range of 0-7 and give hydronium ion when dissolved in water. Acid turns blue litmus red. Whereas base has bitter, its pH is between 7-14 and it turns red litmus blue. It give hydroxide ion when dissolved in water.
Extensive properties, such as mass and volume depend on the amount of substance present and are not useful in the identification of a substance. Measuring mass and volume is not useful While determining acid or base. Out of given compounds, H₃PO₄ is the acid when dissolved in water.
Therefore, H₃PO₄ is the acid when dissolved in water.
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1) If a bottle of olive oil contains 1.3 kg of olive oil, what is the volume, in milliliters, of the olive oil? Express your answer to two significant figures and include the appropriate units. 2) A cannon ball made of iron has a volume of 116 cm^3. What is the mass, in kilograms, of the cannon ball? Express your answer to three significant figures and include the appropriate units. 3) A balloon filled with helium has a volume of 6.1 L. What is the mass, in grams, of helium in the balloon? Express your answer to two significant figures and include the appropriate units.
Answer:
1) 1.4 × 10³ mL
2) 0.913 kg
3) 1.1 g
Explanation:
1)
Step 1: Calculate the volume of 1.3 kg of olive oil
The density of olive oil is 0.917 kg/L.
1.3 kg × (1 L/0.917 kg) = 1.4 L
Step 2: Convert the volume to mL
We will use the relationship 1 L = 10³ mL.
1.4 L × (10³ mL/1 L) = 1.4 × 10³ mL
2)
Step 1: Calculate the mass of the cannon ball
The density of iron is 7.87 g/cm³.
116 cm³ × 7.87 g/cm³ = 913 g
Step 2: Convert the mass to kg
We will use the relationship 1 kg = 10³ g.
913 g × (1 kg / 10³ g) = 0.913 kg
3)
Step 1: Calculate the mass of the helium in the balloon
The density of balloon is 0.18 g/L.
6.1 L × 0.18 g/L = 1.1 g
Name and write one polyatomic ion with its charge.
Answer:
Because these ions contain more than one atom, they are called polyatomic ions. Polyatomic ions have characteristic formulas, names, and charges that should be memorized. For example, NO3− is the nitrate ion; it has one nitrogen atom and three oxygen atoms and an overall 1− charge.
Polyatomic Ions.
Name Formula
sulfite ion SO32−
Explanation:
How many molecules are present in 4.21 moles of HBr?
Answer:
The answer is
2.53 × 10²⁴ moleculesExplanation:
The number of molecules present can be found by using the formula
N = n × Lwhere n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
N = 4.21 × 6.02 × 10²³
We have the final answer as
2.53 × 10²⁴ moleculesHope this helps you
Dinitrogen tetraoxide, a colorless gas, exists in equilibrium with nitrogen dioxide, a reddish brown gas. One way to represent this equilibrium is:
The question is incomplete, the complete question is shown in the image attached
Answer:
F
T
Explanation:
From the equilibrium equation;
N2O4(g) ⇄NO2(g)
We must have to remember that;
1) At equilibrium, the concentration of the species on both sides of the reaction equation may not necessarily be the same but must be held at a constant value because the rate of forward reaction equals the rate of reverse reaction.
2) The rate of forward reaction must equal the rate of reverse reaction.
If the rate of forward reaction is k1 and the rate of reverse reaction is k2. Then it follows that at equilibrium k1 = k2.
How many oxygen atoms will there be in the balanced equation of Al+O2-Al2O3
Answer: 10
Explanation:
4Al + 2O2 --> 2Al2O3
This is the balanced equation so there are 2*2 +2*3 = 4+6 =10
X-rays are often used in medical settings to create images of the body's internal structures such as bones. This is made possible by the
fact that X-rays are able to pass through the body's softer tissues without being absorbed.
Radio waves are also able to pass through the body's softer tissues without being absorbed. Why are radio waves not used to generate
medical images?
OA. The electrons in most atoms are not in high enough energy states to absorb the photons of radio waves.
OB. Radio waves tend to bend too much when they encounter solid materials to be used for generating accurate images,
OC
The frequency of most radio waves is too low to allow them to pass through bones or other solid materials.
OD.
Radio waves carry so little energy that they tend to pass through most atoms without an interaction taking place.
Answer:D
Explanation:I did it on study island.
Radio waves are not used to generate medical images because as per the electromagnetic spectrum ,the radio waves carry little energy that they pass through most atoms without interaction.
What is an electromagnetic spectrum?The electromagnetic spectrum consists of radiation which consists of waves made up of electromagnetic field which are capable of propogating through space and carry the radiant electromagnetic energy.
The radiation are composed of electromagnetic waves which are synchronized oscillations of electric and magnetic fields . They are created due to change which is periodic in electric as well as magnetic fields.
In vacuum ,all the electromagnetic waves travel at the same speed that is with the speed of air.The position of an electromagnetic wave in an electromagnetic spectrum is characterized by it's frequency or wavelength.They are emitted by electrically charged particles which undergo acceleration and subsequently interact with other charged particles.
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Why is the following electron configuration not possible?
1-9-1
Answer: because its noy
Explanation:
Nitrogen dioxide (NO2) gas and liquid water (H2O) react to form aqueous nitric acid(HNO3) and nitrogen monoxide gas. Suppose you have 2.0 mol of NO2 and 7.0 mol of H20 in a reactor. Calculate the largest amount of NHO3 that could be produced. Round your answer to the nearest 0.1 mol.
Answer:
1.3 moles of HNO₃ will be produced
Explanation:
Equation for the reaction:
3NO₂ + H₂O ----> 2HNO₃ + NO
From the equation of the reaction, 3 moles of NO₂ reacts with 1 mole of H₂O to produce 2 moles of HNO₃
Suppose there are 2 moles of NO₂ and 7.0 moles of H₂O in a reactor, the limiting reactant will be NO₂ and H₂O will be in excess since 3 moles of NO₂ reacts with every 1 mole of H₂O.
Since 3 moles of NO₂ reacts to produce 2 moles of HNO₃;
2 moles of NO₂ will react to produce 2/3 * 2 moles HNO₃ = 1.3 moles of HNO₃
Therefore, 1.3 moles of HNO₃ will be produced
The largest amount of HNO₃ produced from the reaction between 2 mole of NO₂ and 7.0 mole of H₂O in a reactor is 1.3 mole
We'll begin by determining the limiting reactant. This can be obtained as follow:
3NO₂ + H₂O —> 2HNO₃ + NO
From the balanced equation above,
3 moles of NO₂ reacted with 1 mole of H₂O.
Therefore,
2 moles of NO₂ will react with = [tex]\frac{2}{3}\\\\[/tex] = 0.67 mole of H₂O.
From the calculation made above, we can see that only 0.67 mole of H₂O out of 7 moles given, reacted completely with 2 moles of NO₂. Thus, NO₂ is the limiting reactant and H₂O is the excess reactant. Finally, we shall determine the largest amount of HNO₃ produced from the reaction. This can be obtained by using the limiting reactant as illustrated below:From the balanced equation above,
3 moles of NO₂ reacted to produce 2 moles of HNO₃.
Therefore,
2 moles of NO₂ will react to produce = [tex]\frac{2 *2 }{3} \\\\[/tex] = 1.3 mole of HNO₃.
Thus, the largest amount of HNO₃ produced from the reaction is 1.3 mole
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