2. Which test for iron(II) ions is conclusive
Answer:
please brainlist answer
Explanation:
The addition of K 3 Fe(CN) 6 to a solution causes the formation of a deep blue precipitate which indicates that iron(II) ions are present.
The conclusive test for iron(II) ions is the test by the use of potassium hexacyanoferrate III solution.
In qualitative analysis certain reagents are used to test for the presence of certain cations or anions. Those reagents react in a certain way with those reagents. Usually, a positive test may involve a color change, formation of a precipitate or evolution of a gas.
In the case of iron(II) ions, potassium hexacyanoferrate III solution is used in the conclusive qualitative test for the ion. A positive test involves the appearance of a deep blue precipitate.
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Which describes a speed?
O A. Moving 8 meters in 2 seconds
O B. Falling down at 100 miles/hr
O C. Moving north at 40 km/hr
O D. Speed changing from 2 km/hr to 5 km/hr
To measure the amount of iron in a certain type of iron ore, an analytical chemist dissolves a sample in strong acid and titrates it to the endpoint with of potassium permanganate solution. The balanced chemical equation for the reaction is:
Answer:
[tex]\% Fe=11.4\%[/tex]
Explanation:
Hello!
In this case, for the described chemical reaction, we find it is:
[tex]8H^+(aq)+5Fe^{2+}(aq)+MnO_4^-(aq)\rightarrow 5Fe^{3+}(aq)+Mn^{2+}(aq)+4H_2O(l)[/tex]
Because it says that the iron is dissolved in a strong acid which provides addition hydrogen ions to the reaction media. Thus, for the questions attached on the figure we find:
- This a REDOX reaction because we see iron is being oxidized from 2+ to 3+ and manganese reduced from +7 to +2.
- Since it is a redox reaction and the oxidized species is that undergoing an oxidation number increase, we evidence iron goes from +2 to +3, which means iron is the oxidized species.
- In this case, for the used 59.2 mL (0.0592 L) of the 0.2000 M solution of potassium permanganate, we can compute the consumed grams of iron via stoichiometry including the 5:1 mole ratio between them in the chemical reaction:
[tex]m_{Fe^{2+}}=0.0592L*0.2000\frac{molMnO_4^-}{L}*\frac{5molFe^{2+}}{1molMnO_4^-} *\frac{55.85gFe^{2+}}{1molFe^{2+}} \\\\m_{Fe^{2+}}=3.31gFe^{2+}[/tex]
It means that the percent of iron in that sample is:
[tex]\% Fe=\frac{3.31g}{29.00g} *100\%\\\\\% Fe=11.4\%[/tex]
Best regards.
Why do you think your new patient, Elisa, is feeling tired all the time? Explain your ideas.
The most plausible reason why your new patient, Elisa, is feeling tired all the time is:
Her body is unable to break down the starch into glucoseAccording to the complete question, we can see that the cells which are in Elise's body are receiving oxygen and proteins, but they are not getting enough glucose, which can be gotten from breaking down starch.
As a result of this, we can see that the best diagnoses of why Elise is always getting tired is that she has diabetes because of the inability of the body to break down starch to provide enough glucose to the body.
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22. In 4f12, the 12 stands for the
The 12 stands for the number of electrons that fill the f orbital
Further explanationIn an atom there are levels of energy in the shell and sub shell
This energy level is expressed in the form of electron configurations.
Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d and f. The maximum number of electrons for each sub shell is
• s: 2 electrons
• p: 6 electrons
• d: 10 electrons and
• f: 14 electrons
4f¹² :
4 : number of shell
12 : the number of electrons that fill the f orbital
an objects kinetic energy increases as its velocity increases?
What is the pH of a solution with a concentration of 1.0 * 10-4 M?
Answer: pH = 10
Explanation: First solve for pOH using the equation pOH=-log[OH-] = 4
Then plug the pOH in the equation, pH + pOH =14
then solve for pH. pH =14 - 4 = 10
Answer:
pH= 10
Explanation:
The pH really depends on what your solution is.
For example, if we are assuming that the concentration of 1.0M is of a strong monoprotic acid e.g. HCl, it would be safe to assume that almost all of the 1.0M acid has dissociated into its H+ ion, and its conjugate base. Thus, the pH can be determined by taking the negative log(to base 10), of the concentration.
Inversely, if the solution is of a strong base, the pOH value would be found, assuming the steps above. This pOH value can be used to infer a pH from the formula - pH + pOH = 14 then 14 - 4 = 10
Finally, come the weak acids/bases, which follow the rules above, except as they only partially dissociate, one needs its equilibrium constant to determine its extent of ionisation, to substitute into the negative log. This also is the case for the second, and higher order dissociation of polyprotic acids e.g. H2SO4.the answer is 10
Hope it helps
How did you organize the tiles in part A? Describe the method that you used.
Periodic table of numbers tiles
Answer:
I ordered the tiles from left to right and top to bottom as the numbers kept increasing. The tiles were also organized based on the color and shape that they were. The tiles with the same color and shape were arranged in the same column.
Explanation:
In the modern periodic table, the elements are listed in order of increasing atomic number and elements having similar chemical properties naturally line up in the same column (group).
5. Psilocybin is made of C 50.70%, H 6.03%, N 9.86%, 22.51%, P 10.90%. a. Find the empirical formula.
The empirical formula : C₁₂H₁₇N₂O₄P
Further explanationThe empirical formula is the smallest comparison of atoms of compound =mole ratio of the components
The principle of determining empirical formula
Determine the mass ratio of the constituent elements of the compound. Determine the mole ratio by by dividing the percentage by the atomic massC
[tex]\tt \dfrac{50.7}{12}=4.225[/tex]
H[tex]\tt \dfrac{6.03}{1}=6.03[/tex]
N[tex]\tt \dfrac{9.86}{14}=0.704[/tex]
O[tex]\tt \dfrac{22.51}{16}=1.407[/tex]
P[tex]\tt \dfrac{10.9}{31}=0.352[/tex]
Divide by the smallest mole ratio(0.352)
C : H : N : O : P
[tex]\tt C\rightarrow \dfrac{4.225}{0.352}=12[/tex]
[tex]\tt H\rightarrow \dfrac{6.03}{0.352}=17[/tex]
[tex]\tt N\rightarrow \dfrac{0.704}{0.352}=2[/tex]
[tex]\tt O\rightarrow \dfrac{1.407}{0.352}=4[/tex]
[tex]\tt P\rightarrow \dfrac{0.352}{0.352}=1[/tex]
A sample of gas is placed into an enclosed cylinder and fitted with a movable piston. Calculate the work (in joules) done by the gas if it expands from 4.22 L to 15.61 L against a pressure of 5.63 atm.
Answer:
The work is -6,497.54 J
Explanation:
Work is the amount of energy transferred from one system to another by a force when a displacement occurs.
The work exchanged for a gas depends on the transformation it performs to go from the initial state to the final state.
The pressure - volume work done by a system that compresses or expands at constant pressure is given by the expression:
W= -P*ΔV
where
W is the work exchanged by the system with the environment. Its unit of measure in the International System is the joule (J), which is equivalent to Pa*m³P: Pressure. Its unit of measurement in the International System is the pascal (Pa). ∆V: Volume variation (∆V = Vfinal - Vinitial). Its unit of measurement in the International System is cubic meter (m³)In this case:
Wsystem=?P= 5.63 atm=570,459.8 Pa (being 1 atm=101325 Pa)ΔV=Vfinal - Vinitial= 15.61 L - 4.22 L= 11.39 L= 0.01139 m³ (being 1 L=0.001 m³)Replacing:
W= -570,459.8 Pa*0.01139 m³
Solving:
W=-6,497.54 J
The work is -6,497.54 J
Which is the Lewis structure for H3PO4? An upper P is single bonded above to an O, and to the left, right, and below to an O single bonded to an H. The O above the P has three pairs of dots to the left, above, and below; the O's to the sides have pairs of dots above and below, and the O below the P has pairs of dots right and left. A central upper P is single bonded left, right, above, and below to upper Os. The O above the P is single bonded to upper H on the left and the right, and has two electron dots above it. The O below the P is single bonded to an H below, and has pairs of electron dots to the left and right. A central upper P is double bonded to an O above, and single-bonded to an upper O single-bonded to an upper H to the left and the right. The O above the P has three pairs of electron dots, to the left, above, and to the right; the O's to the right and left have pairs of dots above and below. A central upper P is bonded to an upper H above, an upper O below, and upper O's bonded to upper H's to the left and the right. The O below the P has three pairs of electron dots, to the left, right, and below; the other two O's have pairs of dots above and below. A central upper P is double bonded to an O above, and single-bonded to an upper O single-bonded to an upper H to the left and the right. The O above the P has three pairs of electron dots, to the left, above, and to the right; the O's to the right and left have pairs of dots above and below.
Answer:
It is A.
Explanation:
I took the test.
The Lewis structure shows the arrangement of valence electrons in H3PO4.
The Lewis structure gives us a picture of the number of valence electrons in a molecule. This is because, in a Lewis structure, the electrons in the molecule are shown as dots. A single line may be used to show shared electrons in a covalent bond.
The correct Lewis structure of H3PO4 is an upper P is single bonded above to an O, and to the left, right, and below to an O single bonded to an H. The O above the P has three pairs of dots to the left, above, and below; the O's to the sides have pairs of dots above and below, and the O below the P has pairs of dots right and left.
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What is the % of H20 in Sodium carbonate decahydrate, Na2CO3 • 10H2O
Answer:
Element Symbol # of Atoms
Sodium Na 2
Cobalt Co 3
Hydrogen H 20
Oxygen O 10
Explanation:
Hat is the answer for this
Answer:
C
Explanation:
Answer:
I think is A
Explanation:
Hope it helps
PLEASE HURRT I NEED HELP ASAP !!!!!!!!!!!!!!
Answer:
I think its b
Explanation:
well because thermal energy its connected to kidnetic energy
Which is a valid reason why total dissolved solids (TDS) cannot be accurately calculated by conductivity alone?
Global warming has significantly increased the conductivity of water.
Big blobs of algae do not conduct electricity.
Fish poop changes the conductivity.
Ionic compounds may behave differently based on ion characteristics (e.g. charge or size).
Some dissolved solids may be nonelectrolytes.
Answer:
The correct option is the last option (Some dissolved solids may be nonelectrolytes)
Explanation:
Total dissolved solids (TDS) cannot be calculated by conductivity alone because conductivity involves ionic charges and there are solids that dissolve in water but do not carry ionic charges (and thus form non-electrolytes). Examples include sucrose (common sugar) and glucose. These two solids will dissolve in water but would not form ions that will carry ionic charges which are responsible for conductivity. Thus, if TDS only depends solely on conductivity, then a solution that contains dissolved sucrose will be wrongly accounted for as the sucrose will be omitted from the dissolved substances.
A valid reason why total dissolved solids (TDS) cannot be accurately
calculated by conductivity alone because some dissolved solids may be
non-electrolytes.
Conductivity means the ability of electric current to pass through a
substance and an electrolyte has a high conductivity when dissolved in
water.
Dissolved solids can't be measured by conductivity because not all
dissolved solids are electrolytes.
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Why is fusion not a practical source of energy?
Answer:
Light i think
Explanation:
light is a source of energy also
is there a relationship between the shape and polarity of the molecule
Answer:hi
Explanation:
Suppose you have equal masses of water, ethanol, and oil (in separate containers). You heat each one from 26 °C to 81 °C. Which one requires the most heat?
a. Oil
b. Ethanol
c. Water
Answer: c. Water
Explanation:
Heat capacity can be defined as the physical property of the matter. It is the amount of heat which is required to produce a unit change in the temperature of the material.
Water requires more amount of energy per gram of the liquid to change its temperature as compare to any other liquid like ethanol and oil. Ethanol is a volatile liquid so it will require less heat to boil but heat capacity of oil will be more than the oil. The heat capacity of water will be the highest, and it will require more heat.
lead(II) nitrate, Pb(NO3)2, and potassium iodide, KI
net ionic equation:
Answer:
Pb²⁺ (aq) + 2I⁻ (aq) → PbI₂ (s)
General Formulas and Concepts:
Solubility RulesReaction PredictionExplanation:
Step 1: RxN
Pb(NO₃)₂ (aq) + KI (aq) → PbI₂ (s) + KNO₃ (aq)
Step 2: Balance RxN
Pb(NO₃)₂ (aq) + 2KI (aq) → PbI₂ (s) + 2KNO₃ (aq)
Step 3: Ionic Equations
Total Ionic Equation:
Pb²⁺ (aq) + 2NO₃⁻ (aq) + 2K⁺ (aq) + 2I⁻ (aq) → PbI₂ (s) + 2K⁺ (aq) + 2NO₃⁻ (aq)
Cancel out spectator ions.
Net Ionic Equation:
Pb²⁺ (aq) + 2I⁻ (aq) → PbI₂ (s)
the layering of rock horizontally is for the __________ only.
A. relative age
B. same age
C. absolute age
Answer:
A
Explanation:
According to valence bond theory, which atomic orbitals of carbon may be hybridized to account for bonding? Why?
.
A. Only 2p orbitals may hybridize; the 2p orbital is carbon’s highest-energy atomic orbital.
B. Only 1s and 2s orbitals of carbon may hybridize; each contains electrons to share in bonding.
C. Only 2s and 2p may hybridize; these orbitals contain valence electrons used in bonding.
D. Only 2s orbitals may hybridize; these orbitals contain valence electrons.
E. 1s, 2s, and 2p orbitals all may hybridize; these orbitals are of the same phase
Answer:
C. Only 2s and 2p may hybridize; these orbitals contain valence electrons used in bonding.
Explanation:
Carbon has four valence electrons (2s² 2p²), in several organic compounds it forms four bonds and as this element has two types of orbitals to join, 2s and 2p, it is expected that a compound like methane has two types of C-H bonds, but this is not the case, as all its orbital atoms are the same.
In a process called hybridization, s orbitals and p orbitals are combined in an atom. Depending on the amount of p orbitals that are combined, the hybrid orbitals can be sp (one orbital 2s and one 2p are combined), sp² (the 2s orbital combines with two 2p orbitals) and sp³(the orbital 2s combines with three 2p orbitals).
The carbon atom has the presence of 6 electrons. The valence bond theory hybridized the 2s and 2p orbital for the bonding, as they have valence bonds.
What is valence bond theory?The valence bond theory has been the atomic hybridization of the atoms that results in the formation of the bonds.
The carbon atom has 4 valence electrons present in the bonding valence orbitals. The orbitals combine as sp, sp2, sp3 orbital in order to form the bond.
Thus, since there has been the presence of valence electrons in the s and p orbitals, the 2s and 2p are involved in the hybridization. Hence, option C is correct.
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please help me out I need some ideas for cell city project or comic strip by tonight or if you did it already lemme copy it={
Answer:
Can you give me your snap, so I can send you the foto
Is mass conserved when 40 g of sodium hydroxide undergoes a chemical change during an interaction with 37g of hydrogen chloride? Use complete sentences to support your answer by explaining how this can be demonstrated. (10 points)
Answer:
Mass is conserverd
Explanation:
Any chemical reaction must follow the law of conservation of mass. Meaning that mass cannot be created nor destroyed. Since all chemical reactions must follow this law, no matter what reaction happens, mass is conserved.
Which functional group is found in an ESTER?
R
R
O=O
R
OR
O
R- OH
R-NH2
Answer:
its hydroxy and alkoxy
Explanation:
ester is mainly formed by substitution reaction of carboxylic acid and alcohol
The esters are generally produced as a result of the reaction called esterification. They are generally derived from carboxylic acids. The functional group present in ester is OR. The correct option is E.
The chemical compounds which are derived from an acid either organic or inorganic in which at least -OH ( hydroxyl group ) is replaced by an -O- alkyl group ( alkoxy ) group are called esters. Generally an ester can be represented as R - C = O - OR.
The chemical compounds that are formed by the reaction of an acid and alcohol by losing water molecule can be defined as the esters.
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Q2 A solution has a (OH-) = 4.0x10^-5 M. What are the [H30+) and the pH of the
solution?
Answer:
[H₃O⁺] = 2.5 × 10⁻¹⁰ M
pH = 9.6
Explanation:
Step 1: Given data
Concentration of OH⁻ in the solution ([OH⁻]): 4.0 × 10⁻⁵ M
Step 2: Calculate the concentration of H₃O⁺ in the solution
Let's consider the self-ionization of water.
2 H₂O(l) ⇄ H₃O⁺(aq) + OH⁻(aq)
The ion-product of water (Kw) is:
Kw = 1.0 × 10⁻¹⁴ = [H₃O⁺] × [OH⁻]
[H₃O⁺] = 1.0 × 10⁻¹⁴/[OH⁻]
[H₃O⁺] = 1.0 × 10⁻¹⁴/4.0 × 10⁻⁵
[H₃O⁺] = 2.5 × 10⁻¹⁰ M
Step 3: Calculate the pH of the solution
We will use the following expression.
pH = -log [H₃O⁺]
pH = -log 2.5 × 10⁻¹⁰
pH = 9.6
Taking into account the definition of pH and pOH, the pH and [H₃O⁺] of the solution is 9.602 and 2.5×10⁻¹⁰ M respectively.
First of all, pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
The pH is defined as the negative base 10 logarithm of the activity of hydrogen ions, that is, the concentration of hydrogen ions or H₃O⁺:
pH= - log [H⁺]= - log [H₃O⁺]
Similarly, pOH is a measure of hydroxyl ions in a solution and is expressed as the logarithm of the concentration of OH⁻ ions, with the sign changed:
pOH= - log [OH⁻]
The following relationship can be established between pH and pOH:
pH + pOH= 14
In this case, you know that [OH⁻]= 4×10⁻⁵ M. For this concentration, the pOH is calculated as:
pOH= - log (4×10⁻⁵ M)
pOH= 4.398
Then, pH can be calculated as:
pH + 4.398= 14
pH= 14 - 4.398
pH= 9.602
So, the [H₃O⁺] is calculated as:
9.602= - log [H₃O⁺]
[H₃O⁺]= 10⁻⁹ ⁶⁰²
[H₃O⁺]= 2.5×10⁻¹⁰ M
Finally, the pH and [H₃O⁺] of the solution is 9.602 and 2.5×10⁻¹⁰ M respectively.
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What is a useful application for this new material?
Answer:
The new material Emily invented allows scratches to be repaired quickly, so it would be useful on cars and other surfaces that experience a lot of wear.
Explanation:
I got this right on Plato\Edmentum
Answer:
The new material Emily invented allows scratches to be repaired quickly, so it would be useful on cars and other surfaces that experience a lot of wear.
Explanation:
What type of relationship exists between two organisms when one organism benefits from the relationship and the other organism becomes prey? (4 points)
a
Commensalism
b
Competition
c
Mutualism
d
Predation
.
.
[tex]
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b competition .
hope it helps u
410X
412
412
410
183
186
183R
Which two are isotopes?
How many milliliters of a 3.4 M NaCl solution would be needed to prepare each solution?
a. 45 mL of a 0.10 M solution:
mL
b. 330 mL of a 0.074 M solution:
mL
Answer:
a. Approximately [tex]1.3\; \rm mL[/tex].
b. Approximately [tex]7.2\; \rm mL[/tex].
Explanation:
The unit of concentration "[tex]\rm M[/tex]" is equivalent to "[tex]\rm mol \cdot L^{-1}[/tex]", which means "moles per liter."
However, the volume of both solutions were given in mililiters [tex]\rm mL[/tex]. Convert these volumes to liters:
[tex]\displaystyle 45\; \rm mL = 45\; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.045\; \rm L[/tex].
[tex]\displaystyle 330\; \rm mL = 330\; \rm mL \times \frac{1\; \rm L}{1000\; \rm mL} = 0.330\; \rm L[/tex].
In a solution of volume [tex]V[/tex] where the concentration of a solute is [tex]c[/tex], there would be [tex]c \cdot V[/tex] (moles of) formula units of this solute.
Calculate the number of moles of [tex]\rm NaCl[/tex] formula units in each of the two solutions:
Solution in a.:
[tex]n = c \cdot V = 0.045\; \rm L \times 0.10\; \rm mol \cdot L^{-1} = 0.0045\; \rm mol[/tex].
Solution in b.:
[tex]n = c \cdot V = 0.330\; \rm L \times 0.074\; \rm mol \cdot L^{-1} = 0.02442\; \rm mol[/tex].
What volume of that [tex]3.4\; \rm M[/tex] (same as [tex]3.4 \; \rm mol \cdot L^{-1}[/tex]) [tex]\rm NaCl[/tex] solution would contain that many
For the solution in a.:
[tex]\displaystyle V = \frac{n}{c} = \frac{0.0045\; \rm mol}{3.4\; \rm mol \cdot L^{-1}} \approx 0.0013\; \rm L[/tex].
Convert the unit of that volume to milliliters:
[tex]\displaystyle 0.0013\; \rm L = 0.0013\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 1.3\; \rm mL[/tex].
Similarly, for the solution in b.:
[tex]\displaystyle V = \frac{n}{c} = \frac{0.02442\; \rm mol}{3.4\; \rm mol \cdot L^{-1}} \approx 0.0072\; \rm L[/tex].
Convert the unit of that volume to milliliters:
[tex]\displaystyle 0.0072\; \rm L = 0.0072\; \rm L \times \frac{1000\; \rm mL}{1\; \rm L} = 7.2\; \rm mL[/tex].
Determine the wavelength of the energy that needs to be absorbed for a 3p electron in chlorine to be promoted to the 4s subshell. Assume that Zeff=6 for a chlorine atom.
Answer:
The wavelength of the energy that needs to be absorbed = 52.36 nm
Explanation:
For this study;
Let consider the Rydgberg equation from Bohr's theory of atomic model:
i.e.
[tex]\dfrac{1}{\lambda} = R_H (Z^*)^2( \dfrac{1}{n_1^2}-\dfrac{1}{n_2^2})[/tex]
where
Z* = effective nuclear charge of atom = Z - σ = 6
n₁ = lower orbit = 3
n₂ = higher orbit = 4
[tex]R_H[/tex] = Rydyberg constant = 1.09 × 10⁷ m⁻¹
λ = wave length of the light absorbed
∴
[tex]\dfrac{1}{\lambda} = 1.09 \times 10^7}(6)^2( \dfrac{1}{3^2}-\dfrac{1}{4^2})[/tex]
[tex]\dfrac{1}{\lambda} = 1.09 \times 10^7}(36)( \dfrac{1}{9}-\dfrac{1}{16})[/tex]
[tex]\dfrac{1}{\lambda} = 392400000\times0.0486111111[/tex]
[tex]\dfrac{1}{\lambda} =19075000[/tex]
[tex]\lambda = \dfrac{1}{19075000}[/tex]
[tex]\lambda = \dfrac{1}{1.91\times 10^7 \ m^{-1}}[/tex]
[tex]\lambda = 5.236 \times 10^{-8} m[/tex]
[tex]\lambda = 52.36 \times 10^{-9} m[/tex]
[tex]\lambda = 52.36\ n m[/tex]
Therefore, the wavelength of the energy that needs to be absorbed = 52.36 nm