Answer:
The two spots will move up the plate.
Explanation:
We have to first understand the rudiments of chromatography. In chromatography, there is a stationary phase and a mobile phase. The stationary phase does not move. In this case, the stationary phase is the TLC plate.
The mobile phase is the solvent used to perform the chromatography. The movement of the spots depends on the composition of the solvent.
When neat hexane was used, only one spot was moved. This must be due to the interaction of the nonpolar hexane with the less polar compound. However, when a 50/50 mixture of hexanes and ethyl acetate is used, the both compounds are found to move up the plate.
An ideal gas that is confined in piston-cylinder assembly (i.e., closed system) goes from an initial state of 1 bar at 300 K to a final state of 3 bar at 300 K by the following two-step process.
Process Path.
(Step 1) Heating at constant volume, and then
( Step 2) Cooling by holding the pressure constant.
Required:
a. Determine the initial and final molar mass.
b. Illustrate the two paths on a pressure-volume diagram. Clearly label the initial and final states, process steps and the direction of each step in the diagram.
Answer:
Explanation:
From the given information;
Using ideal gas equation:
pV = nRT
when n = 1 mol
[tex]V = \dfrac{RT}{p}[/tex]
Initial molar volume = [tex]\dfrac{8.314 \ L.bar .k^{-1}.mol^{-1} \times 300 \ K}{1 \ bar}[/tex]
Initial molar volume = 2494.2 L.mol⁻¹
Final molar volume = [tex]\dfrac{8.314 \ L.bar .k^{-1}.mol^{-1} \times 300 \ K}{3 \ bar}[/tex]
Final molar volume = 831.4 L.mol⁻¹
I need help please my teaching is going to go crazy if I didn’t do it
Answer:
No One is going to answer all this because it hard to type it all in her. its easy to search it up
Explanation:
what structure and bonds are formed in group 1 elements
Looking at the following equation, which is the correct order of coefficients?
NH3 + O2 --> NO + H2O
2NH3 + 302---> 2NO + 3H20
Which term names an icy object that orbits the sun and has a tail?
meteorite
comet
meteor
asteroid
Answer:
Comets are small, icy objects that have very elliptical orbits. When they are close to the Sun, they form comas and tails, which glow and make the comet more visible.
Explanation:
Hope This Helps!!
(brainliest please, if possible)
Answer:
comet's
Explanation:
what the other user said
7. A family used 1,438 kilowatt-hours (kwh) of electricity during the month of
October. Express this amount of energy in joules and Btu. See Appendix A.
Can you please show the steps thanks
Answer:
Im bad at math sorry
Explanation:
A student dissolves 12.1 g of potassium chloride (KCl) in 250. g of water in a well-insulated open cup. He then observes the temperature of the water fall from 21.0 °C to 17.1 °C over the course of 6.9 minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction:
KCl(s) → K (aq) + Cl (aq)
a. Is this reaction exothermic, endothermic, or neither?
b. Calculate the reaction enthalpy ΔH.rxn per mole of KCI.
Answer:
a. Endothermic
b. 26.37kJ/mol
Explanation:
a. As we can see, the temperature of the water is decreasing when the reaction is occurring, that means the reaction is absorbing heat and is endothermic
b. To find the enthalpy we must find the change in heat when 12.1g of KCl are dissolved. Using the equation:
Q = -m*ΔT*C
Where Q is change in heat
m the mass of solution (250g + 12.1g = 262.1g)
ΔT is change in heat (17.1°C - 21.0°C = -3.9°C)
And C is specific heat of the solution (4.184J/g°C assuming is the same than the specific heat of water).
Replacing:
Q = -262.1g*-3.9°C*4.184J/g°C
Q = 4277J = 4.28kJ
As reaction enthalpy is the change in heat per mole of reaction, we must find the moles of 12.1g of KCl:
Moles KCl -Molar mass: 74.55g/mol-:
12.1g KCl * (1 mol / 74.55g) = 0.1623 moles KCl
The reaction enthalpy us:
4.28kJ / 0.1623mol = }
26.37kJ/mol
According to the tow of conservation of matter, we know that the total number of atoms does not change in a chemical reaction and thus mas is conserved This
is part of a chemical reaction hydrogen plus orygon yobis water Can you complete this moder? Reorganize the reactants in order to complete the productie
of the reaction
Your answer:
Answer:
no sé de eso perdón necesito los puntos
The Gulf Stream flows along the equator before turning north along Florida’s east coast. How does the Gulf Stream impact Florida’s climate?
Answer:
The Gulf Stream is influential on the climate of the Florida peninsula.East winds moving over this warm water move warm air from over the Gulf Stream inland, helping to keep temperatures milder across the state than elsewhere across the Southeastern United States during the winter.
Explanation:
hope this helps!
Answer:
The Gulf Stream is influential on the climate of the Florida peninsula.East winds moving over this warm water move warm air from over the Gulf Stream inland, helping to keep temperatures milder across the state than elsewhere across the Southeastern United States during the winter.
Explanation:
Hope This Helps!
For each of the following compounds, decide whether the compound's solubility in aqueous solution changes with pH.
a. Ca(OH)2
b. CuBr
c. Ca3(PO4)2
Answer:
a. pH raises
b. pH neutral
c. pH raises
Explanation:
First of all we need to dissociate these compounds.
Ca(OH)₂ → Ca²⁺ + 2OH⁻
This is the calcium hydroxide, a strong base.
In this case, we are giving OH⁻ to medium, so the pH will be increased.
OH⁻ + H⁺ ⇄ H₂O
Hydroxides will neutralize the protons in order to make water, but if we have many OH, we talk about a basic solution where pH is lower than 7.
b. CuBr → Cu⁺ + Br⁻
This is similar to NaCl, a ionic salt which is neutral.
The ions from this salt, do not make hydrolisis, that's why pH does not change.
c. Ca₃(PO₄)₂ → 3Ca²⁺ + 2PO₄⁻³
Calcium cathion comes from a strong base. It means, that the ion can not make hydrolisis because it is the conjugate weak acid.
Phosphate anion comes from a weak acid, it can gives OH⁻ to medium so pH will increase; the PO₄⁻³ anion is the conjugate strong base of the phosphoric acid, that's why it can react:
PO₄⁻³ + H₂O ⇄ H₂PO⁻² + OH⁻
What is geberal formula for alkane?
Answer:
CnH2n+2
Explanation:
Alkane have double and two atoms of hydrogen than carbon atoms
Like C4H10
n = 4
CnH2n+2
C4H2×4+2
C4H10
Question 6
How many moles of carbon is found in 98.22g of carbon?
Answer:8.18 moles C
Explanation:
98.22g x 1 mole C/ 12.011g = 8.18 moles C
What is the coefficient of iron(lll) carbonate?
Fe(NO3)3 + (NH4)2CO3
? Fe2(CO3)3 + NH4NO3
In the periodic table what is the 65th element? (pls help me)
Answer:
Terbium
Explanation:
All elements are put in squares on the periodic table. They represent the number of protons in the nucleus. They are the largest number in the square. The elements go up in order. Number 65 is in the row following Calcium. It is about in the middle of that row.Of the predators in the image, which one is most likely a keystone species?
O pine marten
O mountain lion
O eagle
O wolf
Answer:
mountian lion
Explanation:
A 1 mL sample weighs 4 g, the density of the sample is
What is the formula for Decaoxygen pentasulfide
Answer:
Compound Formula. 1, Carbon dioxide, CO2. 2, Carbon monoxide, CO. 3, Diphosphorus pentoxide, P2O5. 4, Dinitrogen monoxide, N2O.
Explanation:
dont even know by thoAnswer:
Explanation:
A boy sets up a picnic on the beach next to a sand dune. How are sand dunes formed?
A. erosion and deposition
B. weathering and erosion
C. tectonic plates
D. precipitation
Answer:
B. Weathering and Erosion
Explanation:
I majored in Chemistry
Answer:
b
Explanation:
What would be the structural formula for sodium fluoride? (NaF)
Answer:
Formula and structure: The chemical formula of sodium fluoride is NaF and its molar mass is 41.99 g/mol. It is a simple ionic compound, made of the sodium (Na +) cation and fluoride (F -) anion. The solid salt exists as cubic crystals similar to the crystal structure of sodium chloride (NaCl).
Explanation:
What do scientists use to answer scientific questions?
A. A scientific guidebook
B. The scientific method
C. A scientific law
D. The atomic theory
Scientists uses scientific methods and well designed experiments to solve a scientific question. They can use some laws and previous scientific records as an aid.
What is a scientific question ?A scientific question arises from selected topic under study. A scientific question addresses a natural phenomenon, a socially relevant problem or a any personal curiosity.
The scientific question must be testable. The first prediction for the question based on observation and scientific records is called the hypothesis.
The hypothesis must be tested using a well designed scientific experiment based on a scientific method. The methodology should be clearly specify what to collect and how to use them. Hence, option B is correct.
Find more on scientific methods:
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A compound is 22.5% nitrogen and 77.5% oxygen, What is the empirical formula of
this compound?
Answer:
[tex]NO_3[/tex]
Explanation:
Hello!
In this case, since percent compositions are used to set up empirical formulas when assuming those percentages are masses, we can fist compute the moles of nitrogen and oxygen in the compound as shown below:
[tex]n_N=22.5g/14.01g/mol=1.61mol\\\\n_O=77.5g/16.00g/mol=4.84mol[/tex]
Now, we divide by the fewest moles to compute the subscripts:
[tex]N=\frac{1.61}{1.61} =1\\\\O=\frac{4.84}{1.61} =3[/tex]
Thus, the empirical formula turns out:
[tex]NO_3[/tex]
Best regards!
What are some positive and negative things about living near a volcano?
why metals are good conductor of electricity
Explanation:
silver is the best conductor
Answer:
Metals are an excellent conductor of electricity and heat because the atoms in the metals form a matrix through which outer electrons can move freely. Instead of orbiting their respective atoms, they form a sea of electrons that surround the positive nuclei of the interacting metal ions
Which of the following methods is least likely to help Alisha determine the age of sedimentary rock layers in her backyard?
A. Apply radiometric dating to determine the amount of radioactive isotopes in each rock layer.
B.Identify index fossils in sedimentary rock that have lived in a particular time in Earth’s history.
C. Analyze seismic diagrams to determine how radioactive elements break down into stable elements.
D. Use relative dating techniques to determine how individual fossil groups are related to specific rock layers.
ILL GIVE BRAINLIEST!11
Answer:
i put c
Explanation:
Rocks' ages are determined through radiometric dating, which takes into account the ratio of two different isotopes in a sample. Geologists can use tools like these to assess the age of a material,Mass spectrometer for thermal ionization Thus, option C is correct.
What determine the age of sedimentary rock layers?How rocks are structured in strata and how they fit into the larger geological history are the main topics of stratigraphic study. This approach is best suited for studying sedimentary rocks. Cross dating is a method for using fossils to determine a rock's relative age.
Therefore, Index fossils are sought after by geologists in geological strata. Index fossils are useful because they show the relative dates of the rock layers in which they are discovered. Since radioactive isotopes deteriorate with known time intervals.
Learn more about sedimentary rock here:
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The subatomic particle that is negatively charged and found in the space around the nucleus is
Answer: Electrons
Explanation:
An atom is the smallest unit of the matter and contains neutrons, protons and electrons as subatomic particles.
Neutrons which are neutral and protons which are positively charged are present in the nucleus.
The electrons which are negatively charged revolve around the nucleus in orbits called as shells.
What is the formula for Triphosphorous nonaoxide
1. 1 N2+ 3 H2→2 NH3
c.How many moles of nitrogen are needed to produce 12 moles of nitrogen trihydride?
[tex]\displaystyle 6 \ mol \ N_2[/tex]
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
BracketsParenthesisExponentsMultiplicationDivisionAdditionSubtractionLeft to RightChemistry
Atomic Structure
Writing CompoundsStoichiometry
Using Dimensional AnalysisReactions RxNExplanation:Step 1: Define
[RxN - Balanced] N₂ + 3H₂ → 2NH₃
[Given] 12 mol NH₃
[Solve] x mol N₂
Step 2: Identify Conversions
[RxN] 1 mol N₂ → 2 mol NH₃
Step 3: Stoich
[DA] Set up: [tex]\displaystyle 12 \ mol \ NH_3(\frac{1 \ mol \ N_2}{2 \ mol \ NH_3})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 6 \ mol \ N_2[/tex]Answer:
[tex]\boxed {\boxed {\sf 6 \ moles \ of \ N_2}}[/tex]
Explanation:
1. Balance Equation
We are given the reaction:
[tex]1 N_2+3H_2 \rightarrow 2 NH_3[/tex]
The equation is already balanced. Both sides have 2 moles of nitrogen and 6 moles of hydrogen.
2. Conversions
In this reaction, 1 mole of nitrogen produces 2 moles of nitrogen tryhdride:
[tex]1 \ mol \ N_2 \rightarrow 2 \ mol \ NH_3[/tex]
3. Stoichiometry Calculations
Use the conversion rate as a fraction.
[tex]\frac{ 1 \ mol \ N_2}{2 \ mol \ NH_3}[/tex]
Multiply the number of moles of nitrogen trihydride produced: 12 moles.
[tex]12 \ mol \ NH_3 *\frac{ 1 \ mol \ N_2}{2 \ mol \ NH_3}[/tex]
The moles of nitrogen trihydride cancel.
[tex]12 *\frac{ 1 \ mol \ N_2}{2} = \frac{ 12 \ mol \ N_2}{2}[/tex]
[tex]6 \ mol \ N_2[/tex]
6 moles of nitrogen are needed to produce 12 moles of nitrogen trihydride.
6. Which of the process would you use to remove salt
dissolved in water?
opicean .Filtration, evaporation, chlorination
Answer:
Evaporation
Explanation:
You can use evaporation to separate the salt from the water.
In an experiment, 20cm^3 of 0.2dm^3 NaOH reacted with 32.0cm^3 of H2SO4 solution. Calculate the concentration of the H2SO4 in a) mol dm^-3 and b) g dm^-3
Answer:
A. 0.0625 moldm¯³
B. 6.125 gdm¯³
Explanation:
We'll begin by writing the balanced equation balance equation for the reaction. This is illustrated below:
2NaOH + H₂SO₄ —> Na₂SO₄ + 2H₂O
From the balanced equation above,
The mole ratio of the acid, H₂SO₄ (nₐ) = 1
The mole ratio of the base, NaOH (n₆) = 2
A. Determination of the concentration of the acid in moldm¯³.
Volume of base, NaOH (V₆) = 20 cm³
Concentration of base, NaOH (C₆) = 0.2 moldm¯³
Volume of acid, H₂SO₄ (Vₐ) = 32 cm³
The mole ratio of the acid, H₂SO₄ (nₐ) = 1
The mole ratio of the base, NaOH (n₆) = 2
Concentration of acid, H₂SO₄ (Cₐ) =?
CₐVₐ / C₆V₆ = nₐ / n₆
Cₐ × 32 / 0.2 × 20 = 1 / 2
Cₐ × 32 / 4 = 1 / 2
Cross multiply
Cₐ × 32 × 2 = 4 × 1
Cₐ × 64 = 4
Divide both side by 64
Cₐ = 4 / 64
Cₐ = 0.0625 moldm¯³
Therefore, concentration of the acid in moldm¯³ is 0.0625 moldm¯³
B. Determination of the concentration of the acid in gdm¯³.
Concentration (moldm¯³) = 0.0625 moldm¯³
Concentration (gdm¯³) =?
Next, we shall determine the molar mass of the acid, H₂SO₄. This can be obtained as follow:
Molar mass of H₂SO₄ = (2×1) + 32 + (4×16)
= 2 + 32 + 98
= 98 g/mol
Finally, we shall determine the concentration of the acid in gdm¯³. This can be obtained as follow:
Concentration (moldm¯³) = 0.0625 moldm¯³
Molar mass of H₂SO₄ = 98 g/mol
Concentration (gdm¯³) =?
Conc. (moldm¯³) = conc. (gdm¯³) / Molar mass
0.0625 = Conc. (gdm¯³) / 98
Cross multiply
Conc. (gdm¯³) = 0.0625 × 98
Conc. (gdm¯³) = 6.125 gdm¯³
Thus, the concentration of the acid in gdm¯³ is 6.125 gdm¯³
A flask at room temperature contains exactly equal amounts (in moles) of nitrogen and xenon.
a. Which of the two gases exerts the greater partial pressure?
b. The molecules or atoms of which gas have the greater average velocity?
c. The molecules of which gas have the greater average kinetic energy?
d . If a small hole were opened in the flask, which gas effuses more quickly?
Answer:
a) Same
b) Nitrogen
c) Same
d) Nitrogen
Explanation:
a)
The formula for partial pressure of a gas is equal to
[tex]p_B = n_B \frac{RT}{V}[/tex]
Here nB is the number of moles .
The number of moles for both the gases are same and hence the partial pressure for the two gases will also be same.
b) The greater average velocity is calculated by using following formula
[tex]v_{RMS} = \sqrt{3RTM}[/tex]
Here M is the molar mass.
Molar mass of nitrogen is greater than the molar mass of xenon and hence nitrogen will have higher greater average velocity
c) As we know, the average kinetic energy of gas particles is dependent on the absolute temperature of gas and if all the gases are at same temperature, their kinetic energy will also be same. Since nitrogen and xenon are at same temperature, their kinetic energy will be same
d) Effusivity is depended directly on the thermal conductivity, density and and the specific heat capacity.
All these three parameters are higher in case of nitrogen. Thus, it will effuse first
