Answer:
0.5 M NaOH solution
Explanation:
Initially, we have 0.25L or 250 mL of 8M NaOH solution
Which means that 1L of this solution would have 8 moles of NaOH
Moles present in 250 mL of solution:
Molarity * Volume( in L)
8 * 0.25 = 2 moles
There is 2 moles of NaOH in 0.25 L of the provided NaOH solution
More water is going to be added to this solution but the number of moles of NaOH will remain the same
now that the solution has a volume of 4L after adding the additional water, we have a 4L solution which contains 2 moles of NaOH
Molarity of the new solution:
Molarity = Number of moles in solution / Volume of solution
Molarity = 2 / 4
Molarity = 0.5 M
what are the benefits of using supercritical fluids in EGS
Answer:
See detailed explanation.
Explanation:
Hello.
In this case, it is firstly necessary to cite that EGS accounts enhanced geothermal systems which are man-made reservoirs, placed where lots of hot rock is present but there is lack natural permeability, which requires a fluid to be injected into the subsurface to re-open it and therefore creating permeability.
Typically, water has been used for this purpose, but due to the current issue on saving water alternative methods such as supercritical fluids has been being implemented because they have better dynamic properties such as lower viscosities and therefore larger flow velocities, supercritical CO2 is easy and cheap to get as low temperatures are required to turn it in supercritical condition.
Best regards.!
A block of aluminum weighing 100g is cooled from 108.4°C to 68.2°C
with the release of 1080 joules of heat. From this data, calculate the
specific heat of aluminum
Answer:
Specific heat of aluminum = 0.27 j/g.°C
Explanation:
Given data:
Mass of Al = 100 g
Initial temperature = 108.4°C
Final temperature = 68.2°C
Heat released = -1080 j
Specific heat of aluminum = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 68.2°C - 108.4°C
ΔT = - 40.2°C
Q = m.c. ΔT
-1080 j = 100 g ×c ×- 40.2°C
-1080 j = -4020 g.°C ×c
c = -1080 j/-4020 g.°C
c = 0.27 j/g.°C
Compute the values of the diffusion coefficients for the interdiffusion of carbon in both α-iron (BCC) and γ-iron (FCC) at 900°C. Which is larger? Explain why this is the case.
Answer:
α-iron (BCC) has faster diffusion rate because of lower values in activation energy and pre-exponential value.
Explanation:
Taking each parameters or data at a time, we can determine the values/a constant for each parameters in the diffusion coefficient equation.
For α-iron (BCC), the diffusion coefficient = pre-exponential value,Ao × e^( -Activation energy,AE)/gas constant,R × Temperature.
Converting the given Temperature, that is 900°C to Kelvin which is equals to 1173.15K.
For α-iron (BCC), the pre-exponential value, Ao = 1.1 × 10^-6, and the activation energy, AE = 87400.
Thus, we have that the diffusion coefficient = 1.1 × 10^-6 × e(-87400)/1173.15 × 8.31.
Diffusion coefficient for α-iron (BCC) = 1.41 × 10^-10 m^2/s.
Also, For the γ-iron (FCC), the pre-exponential value, Ao = 2.3 × 10^-5 and the activation energy, AE = 148,00.
From these values we can see that both the exponential value, Ao and the activation energy for γ-iron (FCC) are higher than that of α-iron (BCC).
Thus, the diffusion coefficient for the γ-iron (FCC) = 2.3 × 10^-5 × e ^-(14800)/8.31 × 1173.15.
Then, the diffusion coefficient for the γ-iron (FCC) = 5.87 × 10^-12 m2/s.
Therefore, there will be faster diffusion in α-iron (BCC) because of lower activation energy and vice versa.
1. Determine the electron-domain geometry and molecular geometry for each of the following.
a. SBr2
b. PI4+
c. IBr2−
2. The following three compounds all have the same general formula, XF4. Compare the electron-domain geometries of these three compounds and explain what characteristic(s) of the central atom causes differences in geometry.
a. SiF4:
b. SeF4:
c. XeF4:
Answer:
SBr2: Electron geometry-tetrahedral; molecular geometry-trigonal pyramidal
PI4+: Electron geometry-tetrahedral; molecular geometry-tetrahedral
IBr2−: Electron geometry- Trigonal bipyramidal ; molecular geometry- linear
Explanation:
In SBr2, the molecule is of the structure type AX2E2 hence it is based on a tetrahedron but have two lone pairs of electrons hence the molecular geometry is trigonal pyramidal.
PI4+ has four electron domains and all of them are bond pairs hence both electron geometry and molecular geometry are both tetrahedral.
IBr2- is of the structure type AX2E3 hence it is based on a trigonal bipyramd and has a linear molecular geometry.
2)
SiF4 has a tetrahedral molecular and electron domain geometry because the central atom(Si) has no lone pairs.
SeF4 has a trigonal bipyramidal electron geometry with the structure AX4E. Its molecular geometry is See-saw since it has one lone pair of electrons that causes a deviation from its ideal trigonal bypyramidal geometry.
XeF4 has an octahedral electron domain geometry and the molecule is AX4E2. The two lone pairs are positioned above and below the plane of a square hence the molecule is square planar.
If the visible light spectrum is from 400 to 700 nm, would light with an energy of 2.79 x 10^-19 J be visible with the naked eye? What is the wavelength of this light?
Answer:
713 nm. It is not visible with the naked eye.
Explanation:
Step 1: Given data
Energy of light (E): 2.79 × 10⁻¹⁹ JPlanck's constant (h): 6.63 × 10⁻³⁴ J.sSpeed of light (c): 3.00 × 10⁸ m/sWavelength (λ): ?Step 2: Calculate the wavelength of the light
We will use the Planck-Einstein equation.
E = h × c / λ
λ = h × c / E
λ = 6.63 × 10⁻³⁴ J.s × 3.00 × 10⁸ m/s / 2.79 × 10⁻¹⁹ J
λ = 7.13 × 10⁻⁷ m
Step 3: Convert "λ" to nm
We will use the relationship 1 m = 10⁹ nm.
7.13 × 10⁻⁷ m × (10⁹ nm/1 m) = 713 nm
This light is not in the 400-700 nm interval so it is not visible with the naked eye.
Give Me An Atom With The Following Characteristics Lanthanide series
As temperature decreases, what happens to particles in a material?
Particles become further apart / expand?
Particles become slippery / liquid?
Particles become closer together / contract?
Particles become sticky / plasma?
Answer:
Particles become closer together / contract?
Explanation:
as particles cool down in temp, the particles slow down and compress
Which of the following favors the solubility of an ionic solid in a liquid solvent? Group of answer choices a large magnitude of the solvation energy of the ions a small magnitude of the lattice energy of the solute a large polarity of the solvent all of the above none of the above
Answer:
all of the above
Explanation:
The solubility of an ionic solid in a liquid solvent largely depends on three factors:
i) The solvation energy
ii) The lattice energy of the solid
iii) The polarity of the of the solvent
A large solvation energy and a small magnitude of lattice energy means that the ionic solute will dissolve very easily in the solvent.
Secondly, the solvent must have a large polarity, this is why water serves as a good solvent for most ionic solutes.
an atom contains 31 protons,39neutrons and 31 electrons.Identify the mass number of this atom
Answer:
Atomic mass =70
Explanation:
Mass number is total protons +total neutrons
Draw molecules that satisfy the following prompts:
1. All molecules must have a minimum of 12 Carbon atoms and exactly 3 heteroatoms (not carbon or hydrogen atoms).
2. You may not use the same molecule twice for any parts of this question.
4. You do not need to look up solubility information, but the answers must be reasonable (supported by the concepts that we have discussed). Also, the structures must be reasonable (improper structures, e.g. carbon with 5 bonds or oxygen with one bond and no charge, will not receive any credit).
a. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M HCl(aq) and dichloromethane.
b. Draw two non-charged molecules that will be separated once they are placed in a separatory funnel that contains 2.5 M NaOH(aq) and dichloromethane.
c. Draw two non-charged molecules that will be separated using neutral water and dichloromethane and in a separatory funnel.
Answer:
see images attached
Explanation:
Here we are trying to perform solvent extraction. In solvent extraction, there must be an aqueous phase and an organic phase.
One of the species to be separated is extracted in greater concentration in the aqueous phase while the other is extracted in greater concentration in the organic phase.
The phase into which each specie is extracted depends on the nature of the specie.
Two structures are shown in the images attached that will be separated by the methods shown in (a) (b) (c) in the question
Sketch the titration curve for the titration of a generic weak base B with a strong acid. The titration reaction is
B+H+⇌BH+
On the curve indicate the points that correspond to the following:
a) the equivalence point.
b) the region with maximum buffering) the point where pH = pKbd) the region where pH depends only on [B]e) the region where pH depends only on [BH+]f) the region where pH depends only on the amount of excess strong acid
Answer:
Kindly check the attached picture.
Explanation:
Titration is one of the useful concept or practical in chemistry which is used in the determination of the concentration of a particular chemical specie. Without mincing words, let us dive straight into the solution to the question;
(a) Determining the equivalence point using the graph.
=> The equivalence point is the point at which there has been been "enough" addition of the acid to the base to give us the congugate acid. In the diagram showing the curve, it is the point labelled (a).
(b)The next thing is to determine the region with maximum buffering.
=> The position with the maximum buffering ranges from the point labelled (b) in the graph and it is the point when the acid and the base has been added. But the point with the maximum buffering is labeled as point (c).
(c). Determination of the point where pH = pKb.
=> The Point in which the pH = pKb is the point a
(d). The region where pH depends only on [B].
=> The starting point in the point in which the pH is dependent on the concentration of the base, [B].
(e). The region where pH depends only on [BH+].
=> This is the same point with point labelled as (a). Thus, point (a) and (e) are the same.
(f). The region where pH depends only on the amount of excess strong acid is the point labelled as (f) which is known as the post equivalence point.
The atoms of which element will gain electrons to form an ion?
oxygen
calcium
lithium
mercury
Explanation:
Oxygen will gain electrons to form ion (O²⁻).
Calcium loses electron to form ion (Ca²⁺)
Lithium loses electron to form ion (Li⁺)
Mercury loses electron to form ion (Hg²⁺)
Here it is stated in question that the element will gain electron it means electron bears negative charge.
Therefore,
Option A is correct ✔.
Select the term that matches each definition:
a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion.
b) The mass of a salt in grams that will dissolve in 100 mL of water.
c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved.
d) The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation.
e) The maximum number of moles of a salt that will dissolve in 1 L of solution.
*** Answer options for all questions: ***
- Solubility
- Molar Solubility
- Solubility product constant
- Common ion effect
- Saturated Solution
Answer: a) A decrease in the solubility of an ionic compound as a result of the addition of a common ion : Common ion effect
b) The mass of a salt in grams that will dissolve in 100 mL of water: Solubility
c) A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved: Saturated solution
d) The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation : Solubility product constant
e) The maximum number of moles of a salt that will dissolve in 1 L of solution : Molar solubility
Explanation:
Solubility is expressed usually as the mass of solute per 100 grams or 100 ml of solvent.
Molar solubility of a solid is expressed as the concentration of the dissolved solid in a saturated solution.
Solubility product constant is defined as the equilibrium constant in which a solid ionic compound is dissolved to produce its ions in solution. It is represented as [tex]K_{sp}[/tex]
The common-ion effect is the decrease in solubility of a sparingly soluble salt by the addition to the solution of a soluble compound with an ion in common with the precipitate.
Saturated solution is defined as the solution in which no more solute particles can be dissolved in the solvent.
Write the net ionic equation for the reaction of aqueous solutions of ammonium chloride and iron(III) hydroxide.
Answer:
[tex]Fe(OH)_3(s)\rightarrow Fe^{3+}(aq)+3OH^-(aq)[/tex]
Explanation:
Hello.
In this case, for the reaction between aqueous solutions of ammonium chloride and iron (III) hydroxide, we have the following complete molecular reaction:
[tex]3NH_4Cl(aq)+Fe(OH)_3(s)\rightarrow 3NH_4OH+FeCl_3[/tex]
And the full ionic equation, taking into account that the iron (III) hydroxide cannot be dissolved as it is insoluble in water:
[tex]3NH_4^+(aq)+3Cl^-(aq)+Fe(OH)_3(s)\rightarrow 3NH_4^+(aq)+3OH^-(aq)+Fe^{3+}(aq)+3Cl^-(aq)[/tex]
Finally, the net ionic equation, considering that spectator ions are NH₄⁺, Cl⁻ as they are both the left and right side, therefore, the net ionic equation is:
[tex]Fe(OH)_3(s)\rightarrow Fe^{3+}(aq)+3OH^-(aq)[/tex]
Best regards.
The net ionic equation for the reaction of aqueous solutions should be Fe(Oh)3 ➡Fe3+(aq) + 3OH^-(aq).
Net ionic equation:
When the reaction lies between the between aqueous solutions of ammonium chloride and iron (III) hydroxide
So, here the total reaction should be
3NH4Cl(aq) + Fe(OH)3(s) ➡ 3NH4OH + FeCl3
So, here net ionic equation, considering that spectator ions are NH₄⁺, Cl⁻ since they are both the left and right sides.
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All elements in the same group
Answer:
The elements in each group have the same number of electrons in the outer orbital. Those outer electrons are also called valence electrons. They are the electrons involved in chemical bonds with other elements. Every element in the first column (group one) has one electron in its outer shell.
Explanation:
I'm not really sure what the question is but I hope this helps.
what happens to the temperature of the liquid in a cup of water as some of the water evaporates?
Help
please i’m giving out brainly PLEASEE HELPP
Answer:
Abrasion
Explanation:
Plz can someone help FAST
How does a circuit with a 1.5-volt battery compare to a circuit with a 9-volt battery?
What is the dependent variable? Be specific. *
If a teacher washes the tops of the student
desks with rubbing alcohol daily, the
spread of germs in the classroom may be
diminished.Be specific when you write your answer HELPPPPP I NEED IT ASAP!
Please answer !! For chemistry
Answer:
a. is the correct answer
Explanation:
Cations are always
Question Blank
than the neutral atom.
Using charge to describe an atom
Answer:
this atom has nine electrons
The density for potassium is 0.856 g/cm3. What would be the mass of a 35 cm3 piece of potassium?
Answer:
30 grams
Explanation:
density = mass / volume => mass = density x volume
mass = 0.856 g/cm³ x 35 cm³ = 29.96 grams ≅ 30 grams 2 sig. figs.
Is air a homogeneous heterogeneous mixture or substance
Answer:
look at the explanation
Explanation:
The air that you breathe is a homogeneous mixture of oxygen, nitrogen, argon, and carbon dioxide, along with other elements in smaller amounts. Because each layer of the Earth's atmosphere has a different density, each layer of air is its own homogeneous mixture.
Hope this helps. :)
What is the volume of a substance that has a mass of 59 g and a density of 1.98 g/mL?
(show all work)
Answer:
29.8
Explanation:
The formula for volume is mass/ density, so 59/1.98. 29.8 is the answer.
An element has 20 protons, 22 neutrons and 18 electrons. What is the charge for this ion?
PLZ HELP I'LL AWARD BRAINLIEST
Answer:
20 protons.
Explanation:
20 protons = 20 + charges
18 electrons = 18- charges.
The difference = 20 - 18 = +2
The charge for this ion is plus 2
It is a calcium ion. The element is number 20 on the periodic table.
The charge of the ion is +2
HOW TO DETERMINE THE CHARGE OF AN ION:
The charge of an ion is a function of the number of protons and electrons in the atom. An atom consists of three subatomic particles namely: neutron, proton and electron. The proton is positively charged while the electron is negatively charged. The charge of an atom is determined by subtracting the number of electrons from protons, that is;Charge = no. of protons - no. of electronsHence, if the protons in an atom is more than the electrons, the charge will be positive and vice versa. In this case, an element has 20 protons, 22 neutrons and 18 electrons.Therefore, the charge of the ion will be 20 protons - 18 electrons = +2
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molecular formula of C4H5
Answer:
Cyclopropylmethylene
what isotope of an atom if it has 29 protons and 36 neutrons
Answer:
POTASSIUM
Explanation:
2 8 8 1________ 1A
Suppose you are studying the kinetics of the iodine-catalyzed decomposition of hydrogen peroxide. 2 H 2 O 2 ⟶ 2 H 2 O + O 2 If you determine the initial rate is 7.50 × 10 − 4 M/s when [ H 2 O 2 ] = 0.546 M and [ K I ] = 0.212 M , what is the rate constant? Assume that the order of both reactants is 1.
Answer:
[tex]k=6.48x10^{-3}M^{-1}s^{-1}[/tex]
Explanation:
Hello.
In this case, based on the given information, we can write the rate law as shown below:
[tex]r=k[H_2O_2][KI][/tex]
Since the overall order of reaction is 2 being 1 for reach reactant. Thus, by knowing the initial rate and concentrations, the rate constant turns out:
[tex]k=\frac{r}{[H_2O_2][KI]}=\frac{7.50x10^{-4}M/s}{0.546M*0.212M}\\ \\k=6.48x10^{-3}M^{-1}s^{-1}[/tex]
Best regards!
The rate constant, k is [tex]6.48x10^{-3}M^{-1}s^{-1}[/tex]
Rate law:The rate law should be
[tex]r = k[H_2O_2]{KI}[/tex]
Since the total order of the reaction is 2 being 1 for reach reactant. So, by knowing the beginning rate and concentrations, the rate constant turns out:
[tex]k = \frac{r}{k[H_2O_2]{KI}} = \frac{7.50x10^{-4}M/s}{0.546M\times 0.212M}[/tex]
k = [tex]6.48x10^{-3}M^{-1}s^{-1}[/tex]
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Concentration data is commonly monitored during a reaction to determine the order with respect to a reactant. Consider the types of observations listed, and determine which order is likely for that reactant. Assume all other factors are held constant.
1. An increase in the concentration of the reactant in solution causes the reaction rate to increase exponentially.
a. first order
b. second order
c. zero order
2. The reaction rate increases in direct proportion to the concentration of the reactant in solution.
a. first order
b. second order
c. zero order
3. The reaction rate is constant regardless of the amount of reactant in solution.
a. first order
b. second order
c. zero order
Answer:
1) first order
2) second order
3) zero order
Explanation:
The curve of a first order reaction shows it to be exponential. In fact for a first order reaction, the concentration at a time t is an exponential function;
[A]t= [Ao] e^-kt
Where
[A]t = concentration at time =t
[Ao]= initial concentration
k= rate constant
t= time
For a second order reaction, the rate of reaction is directly proportional to the concentration of reactants.
For zero order reactions, rate of reaction is independent of concentration hence rate = k(rate constant)
The concentration data has been required for the determination of the rate of reaction. Based on the concentration of reactant and product, the rate has been determined.
1. For the first-order reaction, there has been an exponential increase in the rate of the reaction with the increase in the reactant concentration. The rate has been dependent on the concentration of the reactant.
Thus the correct option is A.
2. Irrespective of the first-order kinetic, in the second-order reaction, the rate of reaction has been directly proportional to the concentration of the reactant in the solution.
Thus option B is correct.
3. The zero-order reaction has been independent of the concentration of the reactant. The rate of reaction has been constant with an increase in the reactant concentration.
Thus option C is correct.
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