Moles of MgF₂ : 1.2 x 10⁻⁴
Further explanationMaybe the complete question is like this
A student prepares 100. mL of a saturated solution of MgF2 by adding 0.50 g of solid MgF2 to 100. mL of distilled water at 25°C and stirring until no more solid dissolves. (Assume that the volume of the undissolved MgF2 is negligibly small.) The saturated solution is analyzed, and it is determined that [F−] in the solution is 2.4 × 10−3 M.
The dissociation reaction of MgF₂
MgF₂(s)⇒ Mg²⁺(aq)+2F⁻(aq)
mol ratio MgF₂ : F⁻ = 1 : 2
mol of F⁻ in 100 ml solution :
[tex]\tt mol=M\times V\\\\mol=2.4\times 10^{-3}\times 0.1=2.4\times 10^{-4}[/tex]
mol MgF₂ :
[tex]\tt \dfrac{1}{2}\times 2.4\times 10^{-4}= 1.2\times 10^{-4}[/tex]
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.
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
Consider the two electron arrangements for neutral atoms A and B. What is the atomic number of A?
A - 1s?, 2s 2p6,35
B - 1s2, 2s 2p, 5s
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].
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
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]
Regional Metamorphism occurs when great masses of rock are exposed to pressure. What does this typically form?
Answer:
Gneiss forms by regional metamorphism from both high temperature and pressure. Quartzite and marble are the most commonly used metamorphic rocks.
410X
412
412
410
183
186
183R
Which two are isotopes?
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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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
How many electrons are in the nucleus of an atom with an atomic number of
16?
O None. Electrons are not in the nucleus
08
O 16
O 32
Answer:
None. Electrons are not in the nucleus.
Explanation:
We know that an atom consist of electrons, protons and neutrons. Neutrons and protons are present inside the nucleus while electrons are present out side the nucleus. Electron has a negative charge and is written as e⁻. The mass of electron is 9.10938356×10⁻³¹ Kg . While mass of proton and neutron is 1.672623×10⁻²⁷Kg and 1.674929×10⁻²⁷ Kg respectively.
Symbol of proton= P⁺
Symbol of neutron= n⁰
The number of electron or number of protons are called atomic number while mass number of an atom is sum of protons and neutrons. The umber of protons and electrons are always equal to make the atom electrically neutral .
The atom having atomic number 16 have 16 electrons and these electrons are present out side the nucleus.
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).
Describe how this instrument works.
Operation:
Answer:
Microscope
Explanation:
Answer:
its a telescope you see stars or plants
Explanation:
Naming inconic compounds and lots of iconic naming
if you just look up the answer it comes up btw!!
have a great day
Hat is the answer for this
Answer:
C
Explanation:
Answer:
I think is A
Explanation:
Hope it helps
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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Just wanted to know what the response time is :)
True or False: Scientists use what they know about the properties of different molecules to separate mixtures. *
Answer:
True
Explanation:
Mixtures are substances with indefinite composition. They consist of two or more elements and or compounds in any proportion by mass.
Their constituents retain their identities i.e. physical properties are retained. Their constituents reacts differently to changed conditions. They can easily be separated into constituents by physical methods.From these properties we can clearly identify that to separate mixtures, we use the differences in the chemical properties of the constituents of the mixtures.
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.
J.J. Thomson's plum pudding model of the atom followed the discovery of
A)
negatively charged particles with a very small mass.
B)
positively charged particles with a very large mass.
0)
negative electrons that revolved around a positive nucleus.
D)
positively charged protons that were contained in a concentrated area.
J.J. Thomson's plum pudding model of the atom followed the discovery of negatively charged particles with a very small mass. Thus, the correct option for this question is A.
Who was J. J. Thomson?J.J. Thomson was a British physicist who discovered sub-atomic particles known as electrons within an atom. He also announced that atoms are made up of smaller components.
The plum pudding model is defined by Thomson in order to demonstrate that negatively charged sub-atomic particles known as electrons are surrounded by a volume of positively charged particles known as protons. It is one of the historical scientific model of the atom that governs all sorts of properties of sub-atomic particles.
Therefore, "negatively charged particles with a very small mass" is the discovery that follows J.J. Thomson's plum pudding model of the atom. Thus, the correct option for this question is A.
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10 POINTS PLS HELP
Combustion occurs when _____.
oxidation reactions are very slow
oxidation reactions are so fast the substance catches fire
oxygen is removed from another substance
machines use chemical energy to do work
Answer: oxidation reactions are so fast the substance catches fire
Explanation:
Answer:
When oxidation reactions are so fast the substance catches fire
Explanation:
because i am big bwain
an objects kinetic energy increases as its velocity increases?
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
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 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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the layering of rock horizontally is for the __________ only.
A. relative age
B. same age
C. absolute age
Answer:
A
Explanation:
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
An overhead view of two people at the start of a maze. The person in a purple shirt has a line running forward, right, backward, right, forward, ending with an arrowhead pointing to a large gold star. The person in a green shirt has a line running forward, right, backward, right, forward, right, backward, right, forward, ending with an arrowhead pointing to a small gold star.
Zamir and Talia raced through a maze. Zamir walked 2 m north, 2 m east, 4 m south, 2 m east, 4 m north, 2 m east, 3 m south, 4 m east, and 4 m north. Talia walked 2 m north, 6 m east, 3 m south, 4 m east, and 4 m north.
Compare their distances:
Zamir walked
meters and Talia walked
Answer:
Zamir walked
27
meters and Talia walked
19
meters.
Explanation:
27 and 19
Answer:
zamir:27 Talia:19
Explanation:
i got it right on my test :)
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)