Answer:
The symbol (l) stands for liquid phase.
Explanation:
Metal plating is done by passing a current through a metal solution. For example, an item can become gold plated by attaching the item to a power source and submerging it into an Au³⁺ solution. The item itself serves as the cathode, at which the Au³⁺ ions are reduced to Au(s). A piece of solid gold is used as the anode and is also connected to the power source, thus completing the circuit. What mass of gold is produced when 15.1 A of current are passed through a gold solution for 31.0 min?
Answer:
172 g
Explanation:
Let's consider the reduction of Au³⁺ to Au.
Au³⁺(aq) + 3 e⁻ → Au(s)
In order to find the mass of gold produced, we will use the following relations.
1 min = 60 s1 A = 1 C/sThe charge of 1 mole of electrons is 96,468 C (Faraday's constant).1 mole of Au is deposited when 3 moles of electrons circulate.The molar mass of Au is 196.97 g/mol.The mass of gold produced when 15.1 A of current are passed through a gold solution for 31.0 min is:
[tex]31.0min \times \frac{60s}{1min} \times \frac{15.1C}{s} \times \frac{1mole^{-} }{96,468C} \times \frac{3molAu}{1mole^{-} } \times \frac{196.97gAu}{1molAu} = 172 gAu[/tex]
Calculate the pH of 0.65 M H2SO4 (sulfuric acid) solution? (Ka2: 1.1x10-2)
Answer:
pH = 0.18
Explanation:
The sulfuric acid (H₂SO₄) has the following reactions in aqueous medium:
H₂SO₄ → HSO₄⁻ + H⁺
HSO₄⁻ ⇄ SO₄²⁻ + H⁺ Ka = 1.1x10⁻²
Where Ka is defined as Ka = [SO₄²⁻] [H⁺] / [HSO₄⁻] = 1.1x10⁻²
Based in the first reaction, [H⁺] = 0.65M and [HSO₄⁻] = 0.65M
In the second reaction, the two species are in equilibrium, thus, concentrations will be:
[H⁺] = 0.65M + X
[HSO₄⁻] = 0.65M - X
[SO₄²⁻] = X
Replacing in Ka formula:
1.1x10⁻² = [X] [0.65 + X] / [0.65M - X]
7.15x10⁻³ - 1.1x10⁻²X = 0.65X + X²
0 = X² + 0.661X - 7.15x10⁻³
Solving for X:
X = -0.67M → False solution. There is no negative concentrations.
X = 0.01065M → Right answer.
Thus [H⁺] = 0.65M + 0.01065M = 0.66065M
As pH = -log [H⁺];
pH = -log 0.66065M = 0.18
Which statement best describes the formation of a solution?
A large amount of solute is dissolved in a smaller amount of solvent.
A small amount of solute is dissolved in a larger amount of solvent.
A small amount of solvent is dissolved in a larger amount of solute.
A large amount of solvent is dissolved in a larger amount of solute.
Answer:
A small amount of solute dissolved in a larger amount of solvent.
Take this analogy to help you understand, if you were to put a teaspoon of sugar in a liter of water it would dissolve, but if you put a sack of sugar in it it would not dissolve! The solute is what is being dissolved and the solvent is what dissolves the solute, so that eliminates some of the options.
When Fe2O3(s) reacts with H2(g) to form Fe(s) and H2O(g), 98.8 kJ of energy are absorbed for each mole of Fe2O3(s) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation. Note that the answer box for the energy term is case sensitive. Use the SMALLEST INTEGER coefficients possible and put the energy term in the last box on the appropriate side of the equation. If a box is not needed, leave it blank.
Answer:
Explanation:
Fe₂O₃(s) + 3H₂(g) = 2Fe (s) + 3H₂O - 98.8 kJ .
one mole of ferric oxide reacts with 3 mole of hydrogen to give 2 mole of iron and 3 mole of water . 98.8 kJ of heat is absorbed .
For a theoretical yield of 20 g and actual yield of 12 g, calculate the percent yield for a chemical reaction. Answer in units of %.
Please and Thank you!
Answer:
Percent yield for chemical reaction = 60%
Explanation:
Given:
Theoretical yield of chemical reaction = 20 gram
Actual yield of chemical reaction = 12 gram
Find:
Percent yield for chemical reaction = ?
Computation:
[tex]Percent\ yield \ for\ chemical\ reaction = [\frac{Actual yield}{Theoretical yield} ]100\\\\Percent\ yield \ for\ chemical\ reaction = [\frac{12}{20} ]100\\\\Percent\ yield \ for\ chemical\ reaction = [0.6 ]100\\\\Percent\ yield \ for\ chemical\ reaction = 60[/tex]
Percent yield for chemical reaction = 60%
What is enthalpy?
A. Enthalpy is the heat involved in a reaction.
B. Enthalpy is the temperature of a reaction.
C. Enthalpy is the mass involved in a reaction.
D. Enthalpy is the kinetic energy of a system.
Enthalpy is the heat involved in a reaction.
The enthalpy change is the sum of the internal energy and the product of volume and pressure. Enthalpy is the heat involved in a reaction. The correct option is A.
What is enthalpy?The enthalpy denotes the measurement of energy in a thermodynamic system. The amount of enthalpy equals to the total heat content of a system, equivalent to the system's internal energy plus the product of volume and pressure.
The enthalpy is described as a state function, which indicates that its value depends only on the state of the system and it is independent of the path by which this state has been reached.
The equation of the enthalpy of system is given as:
H = U + PV
Here the enthalpy is represented by the letter 'H'. It is a very important quantity as it gives how much heat or energy is present in the system.
Thus the correct option is A.
To know more about enthalpy, visit;
https://brainly.com/question/1657608
#SPJ7
Find the pH of a solution whose hydronium concentration is 1.0 x 10-11
Answer:
11
Explanation:
pH=-log(H+)
What Science and Math jobs are expected to have much faster than average growth? Check all that apply.
1.Natural Sciences Managers
2.Zoologists and Wildlife Biologists
3.Medical Scientists
4.Food Science Technicians
5 .Biochemists and Biophysicists
6.Mathematical Technicians
Answer:
3.Medical Scientists
5.Biochemists and Biophysicists
Explanation:
Science and Math jobs are expected to have much faster than average growth. Medical Scientists and Biochemists and Biophysicists is correct.
What is biochemist ?Scientists with biochemistry training are known as biochemists. They research the chemistry of living things, including chemical reactions and changes. Biochemists research DNA, proteins, and cellular components. A portmanteau of "biological chemist" is the term "biochemist."
The study of biochemistry focuses on the chemistry of living things. It is a lab-based science that combines chemistry and biology.
Biochemists investigate the makeup, chemistry, and chemical processes of the compounds found in living things in order to understand how they work and how to manipulate them.
Thus, option 3 and 5 both are correct.
To learn more about biochemist follow the link;
https://brainly.com/question/18524947
#SPJ5
Substituents on an aromatic ring can have several effects on electrophilic aromatic substitution reactions. Substituents can activate or deactivate the ring to substitution, donate or withdraw electrons inductively, donate or withdraw electrons through resonance, and direct substitution either to the ortho/para or to the meta positions.
1. From the following list, select the substituents that have the indicated property. The substituents are written as -XY, where X is the atom directly bound to the aromatic ring.
a. Activation of the ring towards substitution
i. -CF3
ii. -NO2
iii. -OCOCH3
iv. -NH2
Answer:
iv. -NH₂
Explanation:
The amine group is an activating substituent and provides an ortho-para orientation.
The free electrons in the nitrogen atom provide stabilization by resonance in the sigma complex if the attack by the electrophilic reactant occurs in the positions ortho or para with regards to the nitrogen atom.
Is HSO4- a polar or non polar molecule
Answer:
Polar molecule.
Explanation:
Hello,
In this case, hydrogen sulfate has in its structure sulfur-oxygen and oxygen-hydrogen bonds which are both polar since the electronegativity difference is between 0.7 and 1.7 (0.86 and 1.24 respectively), for that reason, such quality makes hydrogen sulfate a polar molecule, for that reason it is largely soluble in water.
Best regards.
Use the drop-down menus to fill in the
corresponding cells in the table to the right.
Answer:
a: 1 amu
b: +1
c: neutron
d: 1 amu
Explanation:
Iron (Fe) undergoes an allotropic transformation at 912°C: upon heating from a BCC (α phase) to an FCC (γ phase). Accompanying this transformation is a change in the atomic radius of Fe—from RBCC = 0.12584 nm to RFCC = 0.12894 nm. The highest density planes in BCC structure is (110) and for FCC structure is (111). i. Compare the planar density of the two. (110) in BCC and (111) in FCC iron. EA = − 1.436 r ER = 5.8 × 10−6 r 9 ii. Do you think a (111) plane in FCC structure is more amenable to dislocation motion or (110) plane in BCC structure? What is an implication of that on the mechanical properties of materials.
Answer:
The description including its given problem is outlined in the following section on the clarification.
Explanation:
The given values are:
RBCC = 0.12584 nm
RFCC = 0.12894 nm
The unit cell edge length (ABCC) as well as the atomic radius (RBcc) respectively connected as measures for BCC (α-phase) structure:
√3 ABCC = 4RBCC
⇒ ABCC = [tex]\frac{4RBCC}{\sqrt{3} }[/tex]
⇒ = [tex]\frac{4\times 0.12584}{\sqrt{3}}[/tex]
⇒ = [tex]0.29062 \ nm[/tex]
Likewise AFCC as well as RFCC are interconnected by
√2AFCC = 4RFCC
⇒ AFCC = [tex]\frac{4RFCC}{\sqrt{2}}[/tex]
⇒ = [tex]\frac{4\times 0.12894}{\sqrt{2} }[/tex]
⇒ = [tex]0.36470 \ nm[/tex]
Now,
The Change in Percent Volume,
= [tex]\frac{V \ final-V \ initial}{V \ initial}\times 100 \ percent[/tex]
= [tex]\frac{(VFCC)unit \ cell-(VBCC)unit \ cell}{(VBCC)unit \ cell}\times 100 \ percent[/tex]
= [tex]\frac{(aFCC)^3-(aBCC)^3}{(aBCC)^3}\times 100 \ percent[/tex]
= [tex]\frac{(0.36470)^3-(0.29062)^3}{(0.29062)^3}\times 100 \ percent[/tex]
= [tex]97.62 \ percent (approximately)[/tex]
Note: percent = %
3. Consider the transport of galactose across a semi-permeable membrane from the extracellular space ([galactose] = 2 mM) to the cytosol ([galactose] = 10 mM) under biochemically standard conditions. (R = 0.08206 L atm/mol K = 8.314 J/mol K) (15 pts.) If ATP hydrolysis liberates 30.5 kJ/mol at standard conditions, approximately how many grams of ATP (507.2 g/mol) would be required to transport 260 g of galactose from the extracellular space to the cytosol?
Answer:
15.63.
Explanation:
So, from the question, we are given the following parameters or data or information for solving this particular Question and they are;
(1). "semi-permeable membrane from the extracellular space ([galactose] = 2 mM) to the cytosol ([galactose] = 10 mM) under biochemically standard conditions. (R = 0.08206 L atm/mol K = 8.314 J/mol K) (15 pts.) "
(2). "If ATP hydrolysis liberates 30.5 kJ/mol at standard conditions".
(3). " (507.2 g/mol) would be required to transport 260 g of galactose from the extracellular space to the cytosol"
Step one: determine the difference to transport of galactose from extracellular space to cytosol.
This can be done by using the formula below:
Ratio = intracellular/ extracellular.
=> 10/2 = 5 mM.
Step two: so, from statement (2) and (3), the if 507.2 g/mol ATP = 30.5 kJ/mol, then 260 g/mol = ???
Therefore, 260 × 30.5 / 507.2 = 15.63 is the energy required.
does nitrous oxide in a car kill the car or help it
Answer:
it makes it go faster
Explanation:
(14.1.50) 0.03 mol of helium are enclosed in a cylinder with a piston which maintains a constant pressure in the helium. Initially the helium is immersed in thermal bath with at 250K. Suddenly, the helium is removed from this thermal bath and plunged into a thermal bath at temperature 350K. Determine (a) the increase in the entropy of the helium. (Hint the entropy change for the helium is the same as if it had been taken through this temperature change by a reversible process.) (b) the increase in entropy of the universe. (Answer: 0.032 J/K)
Answer:
a) 0.210 j /k
b) 0.032 j/k
Explanation:
Find the attachment for solution
Please help me
*science *
Answer: Solar energy
Explanation:
Solar energy because it has more clear and sunny skys
Hello there!
An alternative energy source that is best for Coalville is wind energy.
The first two options, solar power and hydroelectric power aren't very good options since solar power requires lots of sun and they only receive 70 days of sun. While, hydroelectric power isn't a good choice either since it is a small stream meaning very little water and not big enough to build a dam on.
Therefore, wind energy is the best idea since high wind speeds are good to spin the wind turbines. The faster the wind the more energy is produced. Coalville has an average windspeed of 20 mph which is quite fast so that will the best option.
What is the net electric charge of an ionic compound?
Ionic compounds contain both cations and anions in a ratio that results in no net electrical charge
Which of the two compounds, H_2NNH_2 and HNNH, has the strongest nitrogen-nitrogen bond, and which has the shorter nitrogen-nitrogen bond.
a. H_2NNH_2 has the strongest nitrogen-nitrogen bond and HNNH has the shorter nitrogen-nitrogen bond.
b. H_2NNH_2 has both the strongest nitrogen-nitrogen bond and the shorter nitrogen-nitrogen bond.
c. HNNH has the strongest nitrogen-nitrogen bond and H_2NNH_2 has the shorter nitrogen-nitrogen bond.
d. HNNH has both the strongest nitrogen-nitrogen bond and the shorter nitrogen-nitrogen bond.
Answer:
d. HNNH has both the strongest nitrogen-nitrogen bond and the shorter nitrogen-nitrogen bond.
Explanation:
The Lewis structure of HNNH comprises of a double bound between the two nitrogen atoms, therefore each nitrogen still carrying a lone pair of electron and a single bond between each nitrogen to it respective hydrogen.
Also for H_2NNH_2; there exists a single nitrogen to nitrogen bond because hydrogen is sharing two bonds already with the nitrogen; the nitrogen also possess a lone pair of electron and the last bond is a single bond between the nitrogen to nitrogen atom ( therefore obeying the octet rule).
The bond strength and bond angle is stronger and shorter in double bonds than single bonds, thus HNNH has both the strongest nitrogen-nitrogen bond and the shorter nitrogen-nitrogen bond.
Answer:
d. HNNH has both the strongest nitrogen-nitrogen bond and the shorter nitrogen-nitrogen bond.
Explanation:
The Lewis structure of HNNH comprises of a double bound between the two nitrogen atoms, therefore each nitrogen still carrying a lone pair of electron and a single bond between each nitrogen to it respective hydrogen.
Also for H_2NNH_2; there exists a single nitrogen to nitrogen bond because hydrogen is sharing two bonds already with the nitrogen; the nitrogen also possess a lone pair of electron and the last bond is a single bond between the nitrogen to nitrogen atom ( therefore obeying the octet rule).
The bond strength and bond angle is stronger and shorter in double bonds than single bonds, thus HNNH has both the strongest nitrogen-nitrogen bond and the shorter nitrogen-nitrogen bond.
what are the implications of increased amount of CO2 in the atmosphere
Answer:
global warming and destruction of the ozone layer
Explanation:
if Carbon dioxide are high in number , it will cause destruction of the ozone layer which will result to global warming
What is the unit volume in mL
Answer:
4.35 mL
Explanation:
The water line falls halfway inbetween the 4.4 and 4.3 mark.
The number halfway between 4.3 and 4.4 is 4.35.
Therefore, the volume of the liquid in the graduated cylinder is 4.35 mL.
nswer the following questions relating to HCl, CH3Cl, and CH3Br.HCl(g), can be prepared by the reaction of concentrated H2SO4(ag), with NaCl(s), asa.represented by the following equation.H2SO4(ag) + 2 NaCl(s) → 2 HCl(g) Na2SO4(ag)A student claims that the reaction is a redox reaction. Is the student correct?i.Justify your answer.Calculate the mass, in grams, of NaCl(s), needed to react with excess H2SO4(ag)ii.to produce 3.0 grams of HCl(g). Assume that the reaction goes to completion
Answer:
It is an example of double displacement reaction.
4.8 g of NaCl is needed to react.
Explanation:
Balanced reaction: [tex]H_{2}SO_{4}(aq.)+2NaCl(s)\rightarrow 2HCl(g)+Na_{2}SO_{4}(aq.)[/tex]
Here, oxidation states of H, S, O, Na and Cl do not change during reaction. Hence it is not a redox reaction.
In this reaction, cations and anions of the reactants interchange their partners during reaction. Hence, it is an example of double displacement reaction.
As [tex]H_{2}SO_{4}(aq.)[/tex] remain in excess amount therefore NaCl (s) is the limiting reagent. Hence production of HCl entirely depends on amount of NaCl used.
Molar mass of HCl = 36.46 g/mol
So, 3.0 g of HCl = [tex]\frac{3.0}{36.46}[/tex] mol of HCl = 0.082 mol of HCl
According to balanced equation-
2 moles of HCl are produced from 2 moles of NaCl
So, 0.082 moles of HCl are produced from 0.082 moles of NaCl
Molar mass of NaCl = 58.44 g/mol
So, mass of 0.082 moles of NaCl = [tex](0.082\times 58.44)[/tex] g = 4.8 g
Hence 4.8 g of NaCl is needed to react.
What evidence supports the claim that social media
had more of an influence outside of the Arab world than
inside it?
Sixty five percent of Egyptians do not use the
internet at all
Eighty four percent of internet users visit social
networking sites for political news,
College educated people are more likely to use the
internet
Social media sites use bitly links to help spread
information
Answer:
Option A) Sixty-five percent of Egyptians do not use the internet at all.
Explanation:
Did it on edg
Answer:
A. 65% of Egyptians do not use the internet at all
Explanation:
Brainliest Answer Please!
Which of the following terms is defined by the measure of mass per unit of volume?
gravity
density
weight
acceleration
Answer:
I'm glad you asked!
Explanation:
Gravity is a force which keeps people from floating around.
Density is usually used for mass or volume.
Weight is how heavy something is.
Acceleration is when something increases in height,speed etc.
The answer is Density.
Which phase has the lowest entropy? Why? How does a change in phase affect entropy changes in a reaction?
Answer:
The solid phase has the lowest entropy.
Explanation:
Entropy (S) is the measure of how spread out or dispersed the energy of a system is among the different possible ways that system can contain energy. The greater the dispersal, the greater is the entropy.
In a solid, the atoms or molecules are confined to fixed positions, thus, the dispersal is minimal and the entropy is at its lowest.
How many ng are there 5.27x10-13 kg
Answer:
This involves metric conversion and one can easily use dimensional analysis, assuming you know the conversion factors.
1 ng = 10-9 g, or put another way 109 ng = 1 g
1 kg = 103 g
5.27x10-13 kg x 1 g/1x10-3 kg x 1x109 ng/g = 5.27x10-1 ng = 0.527 ng
Looking at the individual steps and following the units, we have...
5.27x10-13 kg x 1 g/1x10-3 g = 5.27x10-10 g (kg cancel leaving g)
5.27x10-10 g x 1x109 ng/g = 5.27x10-1 ng = 0.527 ng (g cancel leaving ng)
assume you have a 500 g sample of a radioactive isotope with a half-life of 100 years. fill in the table showing how many grams of material will remain after the indicated time has passed.
The half-life of carbon-14 is 5,715 years. After 29,000 years (5 half-lives) have elapsed, how much carbon-14 remains in a sample
that originally contained 0.32 g of carbon-14
A 0.0409
B. 0.0809
C 0.109
D. 0.0109
E 0209
After 3 half-life, 12 of the 14 of the C-14 = 18 of the C-14 would remain.
Sketch the simple Lewis dot structures and the predicted VSEPR
shapes for each of the following species. Be sure to clearly indicate
lone pair electrons, multiple bonds (double or triple), and any three-
dimensionality (using dashes and wedges). For any ions, don’t forget
to account for the charge when calculating valence electrons! Only
expand the octet of the central atom when absolutely necessary.
A. CO2
B. CS2
C. SeCL
D. SO2
E. SO32-
F. CO32-
G. N3-
Answer:
Check the explanation
Explanation:
Kindly check the attached image below to see the step by step explanation to the question above.
How do limiting factors affect organisms in a community
Answer: Both biotic and abiotic limiting factors can limit organisms' ability to live or reproduce.
Explanation:
penn foster
n the space below, briefly explain why the average times for the two CO2 molecules you calculated should have been similar (or at least not significantly different). If a CO2 molecule starts out surrounded by other CO2 molecules, does this influence how quickly it will reach the other side of the leaf? You might find it helpful to reset the simulation and to re-examine the initial configurations of molecules. Collisions influence how molecules move, but do molecules only collide with other molecules of the same substance?
Answer:
See explaination
Explanation:
No, the neurons don't use diffusion to transfer messages rather they employ the use of electrical impulses which are very fast for example, if we drop something accidentally on our foot we immediately move back to prevent ourselves from injury this quick reaction is possible because the signals are transferred in the form of electrical impulses.If diffusion was there to transfer the message then it would have taken very long time and our foot would have been bleeding too as diffusion process is relatively much slower.
This is due to collision of CO2 molecule with other molecules of CO2 and vander vals interaction between them which results in slow down of CO2 molecule and the CO2 molecules also collide with walls of leaf as well which also decreases the speed of CO2 molecule resulting it in taking more time.