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1.4. A 2.3 L cylinder containing nitrogen gas at a pressure of 2.8 atm is connected to a 5.5 L ...

r containing nitrogen at 17.3 atm. What is the final pressure when both the cylinders have achieved equilibrium (reached the same pressure)?
6. An analytical procedure requires a solution of chloride ions. How many grams of BaCl2 must be dissolved to make 360 ml of 0.2 M Cl– ?
(M BaCl2 = 208 g/mol)
7. Find the concentration of chloride ions when 344.4 mL of 2.4 M NaCl is mixed with 364 mL of 2.9 M KCl?
8. A sample of an unknown gas had a density of 1.45 g/L at 20.5 °C and 1.2 atm. Calculate the molar mass of the gas.
(R = 0.08206 L·atm·mol-1·K-1)

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2.24) At 25 oC, what is the pOH of a 2.50 x 10–3 M aqueous HCl solution? 25) How many mLs ...

an aqueous 0.1125 M NaOH solution will it take to titrate 25.00 mL of an aqueous 0.05256 M H2SO4 solution to equivalence (25 oC)?

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3.How much potential energy is stored in an apple, mass 0.156 kg, that is in a tree 2.6 m above the ...

round? Round your answer to the tenths place.

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titrated with a 0.200 M solution of the base, LiOH.
Write the balanced chemical reaction for neutralization reaction:
HClO4 (aq) + LiOH (aq) → LiClO4 (aq) + H2O (l)
Write the NET ionic equation for the neutralization reaction.
OH⁻ (aq) + H⁺ (aq) → H2O (l)
Compute the pH of the titration solution. Show your work
i) before any of the base is added
ii) after 25. mL of base is added
iii) after 50. mL of base is added
A student performs the titration with the same chemicals but with smaller volumes of each chemical . Which of the following titration curves could represent the titration. Explain
A because this entails a strong acid and a strong base.
Question 2
A student performs a titration of an unknown acid with a strong base and gets the following titration curve:
a) The student consults the list of pKa of acids shown below. If the acid is listed in the table below, which is the most likely identity of the unknown acid? Explain.
Acid
Ka
HF
7.2 x 10-4
CH3COOH
1.8 x 10-5
H2CO3
4.3 x 10-7
HBrO
2.0 x 10-9
The unknown acid is HBrO because the calculated Ka is in between 50^-4 and 50^-6 and 2.0 x 10^-9 lies in between them.
b) What is the initial molarity of the acid?
10^-3 = 0.001M
Question 3
a) Describe the components and the composition of an effective buffer solution. Explain how the components of the buffer allow the buffer to maintain its pH.
An effective buffer solution has a weak acid and its conjugate base or a weak base and its conjugate acid. A buffer solution is most effective when the ratio of its component concentrations is close to 1, also when the pH is equal to the pka of the acid.; The components of the buffer allow the buffer to maintain its pH because buffers can absorb excess H+ions or OH– ions.
An employer is interviewing four applicants for a job as a laboratory technician and asks each how to prepare a buffer solution with a pH of 5.0. The following constants may be helpful: hydrazoic acid, pKa = 4.74 Boric acid, pKa = 9.23
Archita A. says she would mix equal molar solutions of hydrazoic (HN3) and sodium azide (NaN3) solutions.
Bradley B. says she would mix equimolar Boric acid (H3BO3) and HCl solutions.
Carlos C. says he would mix equimolar Boric Acid (H3BO3) and sodium dihydrogen borate (NaH2BO3) solutions.
Delia D. says he would mix equimolar hydrazoic Acid (HN3) and NaOH solutions.
b) Which of these applicants has given an appropriate procedure? Explain your answer
Delia because she is using Sodium hydroxide which results in a pH of 5. NaOH is a strong base and in order to have an effective buffer a weak acid must be incorporated which is the HN3.
c) Explain what is wrong with the erroneous procedures.
The rest all incorporate a strong acid and a strong base or a weak acid and a weak base which don’ result in an effective buffer.
d) The applicants have access to the 1 Liter volumes of each of the solutions listed above. They have access to graduated cylinders. In order to make 1.0 Liter of the correct 5.0 buffer solution, what volumes of the two chemicals must be mixed?

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a) A scientific theory must be able to be proven.
b) A scientific theory has been derived from known facts and always applies.
c) A scientific method should give different results depending on who performs the method.
d) Knowledge of our surroundings usually emerges through an interplay between theory and experiment.
2) The sides of a straight block are measured to 3,202 cm; 0.0012 cm and 11.2 cm, respectively. Calculate the volume of the straightening block and enter it with the correct number of value digits.
(2/0/0)
Number of words: 0
3) A 9.2 dm long and evenly thick rod rests on a support. 0.55 dm from one end, a dynamometer is hung so that the rod will hang horizontally. Then the dynamometer shows 4.4 N. How much does the bar weigh?
(1/1/0)
Number of words: 0
4) A bar AB that is homogeneous and evenly thick has a length of 2.70 m and is rotatable about an axis at A. The bar weighs 25 kg and is kept in equilibrium by a force F which has its point of attack in B. is 45 degrees. How big is the force F?
(1/1/0)
Saved!
25 * 9.82 = 245.5 N
Number of words: 6
5) A trolley rolls at a constant speed to the right. On the cart is an upward cannon that suddenly shoots a bullet. The carriage continues to the right with the same speed as before. Where does the bullet end up when it falls? For a detailed reasoning.
(1/1/1)
Number of words: 0
6) A river is 200 m wide. The water in the river flows at a speed of 2.5 m / s. A motorboat steers across the river at its maximum speed, which in stagnant water is 5.0 m / s. The boat is constantly heading perpendicular to the banks of the river. Where does the motorboat land on the other shore?
(2/0/0)
Number of words: 0
7) A ball with a mass of 2.0 hg moves at a constant speed in a circular path. The radius of the track is 1.5 m and it takes the ball 3.0 seconds to move one turn. How big is the centripetal force?
(1/1/0)
Number of words: 0
8) A bullet moves at a constant speed. Can we then safely say that the resultant of the forces acting on the bullet is zero? Motivate and discuss your answer.
(0/1/1)
Number of words: 0
9) A conductor is located between the poles of a permanent magnet. The current in the conductor goes in the direction of the plane of the paper (away from the reader). How is the force acting on the leader directed?
(1/0/0)
a) To the right of the figure
b) To the left in the figure
c) Downwards in the figure
d) Upwards in the figure
10) Protons enter horizontally from the left between two large metal plates at a speed v = 0.80 Mm / s. The plates are connected to a voltage source with the pole voltage U. Between the plates there is a homogeneous magnetic field with a flux density of 38 mT directed perpendicular to the plane of the paper. The distance between the plates is 1.5 cm. They want the protons to continue with unchanged direction and speed between the plates. Which of the plates should be connected to the positive pole of the voltage source and how large should the voltage U be?
(0/2/0)
Number of words: 0
11) The magnetic flux Φ through a 700-speed coil decreases linearly with time according to the diagram below. Calculate the voltage across the coil at time t = 1.0 ms.
12) The current in a coil with an inductance of 35 mH has a growth rate of 6.2 A / s at a given moment. What is the instantaneous value of the ems induced in the coil?

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hin a free demo session as I have my answers, but just want to confirm them, that would be greatly appreciated.
Question 1:
A block of mass M = 0.10 kg is attached to one end of a spring with spring constant k = 100 N/m . The other end of the spring is attached to a fixed wall. The block is pushed against the spring, compressing it a distance x = 0.04 m . The block is then released from rest, and the block-spring system travels along a horizontal, rough track. Data collected from a motion detector are used to create a graph of the kinetic energy K and spring potential energy Us of the system as a function of the block's position as the spring expands. How can the student determine the amount of mechanical energy dissipated by friction as the spring expanded to its natural spring length?
Question 2:
The Atwood’s machine shown consists of two blocks connected by a light string that passes over a pulley of negligible mass and negligible friction. The blocks are released from rest, and m2 is greater than m1. Assume that the reference line of zero gravitational potential energy is the floor. Which of the following best represents the total gravitational potential energy U and total kinetic energy K of the block-block-Earth system as a function of the height h of block m1?
Question 3:
A 2 kg block is placed at the top of an incline and released from rest near Earth’s surface and unknown distance H above the ground. The angle θ between the ground and the incline is also unknown. Frictional forces between the block and the incline are considered to be negligible. The block eventually slides to the bottom of the incline after 0.75 s. The block’s velocity v as a function of time t is shown in the graph starting from the instant it is released. How could a student use the graph to determine the total energy of the block-Earth system?
Question 4:
A block slides across a flat, horizontal surface to the right. For each choice, the arrows represent velocity vectors of the block at successive intervals of time. Which of the following diagrams represents the situation in which the block loses kinetic energy?

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7. A tree grows at angle of 87° in Kayleigh’s backyard. Kayleigh wants to know the height of the tree. ...

ee. She walks 65 m
from the tree and measures an angle of elevation of 35° to the top of the tree. How tall is the tree?

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etically engineered killer hounds patrolling the grounds of the FORTRESS OF MISERY. Fortunately, Captain Proton has a piece of bone to whittle into a flute (assume this is a tube open at both ends). A sound with a frequency of 23015 Hz will disable the Killer hounds. Assuming a speed of sound of 334 m/s, how long must the flute be so that its fundamental frequency will disable the Killer Hounds? (3 points)
2. The delivery entrance of the FORTRESS OF MISERY is guarded by a Destructo-Bot that is programmed not to respond to any sound less than 50 dB in relative intensity. Captain Proton will set off a small explosion 10.0 m from the Bot. How much power must the explosion’s sound carry in order to exceed 50 dB at the Bot’s position. Assume that I0 is 1.0*10-12¬¬ W/m¬2. Surface area of a sphere = 4πr2. (5 points)
that is due tonight

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ed killer hounds patrolling the grounds of the FORTRESS OF MISERY. Fortunately, Captain Proton has a piece of bone to whittle into a flute (assume this is a tube open at both ends). A sound with a frequency of 23015 Hz will disable the Killer hounds. Assuming a speed of sound of 334 m/s, how long must the flute be so that its fundamental frequency will disable the Killer Hounds? (3 points)
2. The delivery entrance of the FORTRESS OF MISERY is guarded by a Destructo-Bot that is programmed not to respond to any sound less than 50 dB in relative intensity. Captain Proton will set off a small explosion 10.0 m from the Bot. How much power must the explosion’s sound carry in order to exceed 50 dB at the Bot’s position. Assume that I0 is 1.0*10-12¬¬ W/m¬2. Surface area of a sphere = 4πr2. (5 points)

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d lead (II) sulfate precipitates
(a) Write a balanced chemical equation for the reaction
(b) Write the net ionic equation for the reaction
(c) What type of reaction is occurring?
(d) What is the limiting reagent? The excess reagent?
(e) How many grams of lead (II) sulfate are formed?
(f) In the lab, a chemistry student mixed the two solutions together and formed 9.40 g of lead (II) sulfate. What percent yield did the student obtain?

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The ball lands 601 m away from the cannon. How far above ground level is the cannon?

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3.0 m and then returned to its original position. How much work did gravity do on the bucket during this process? Thank you

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h = ???????? − where h m is the height of the jet of water above the ground after t seconds.
(a) How long does it take for the jet of water to hit the ground? Show your working.

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14.A spring with stiffness constant 45.0 N m is attached to the side of a 2.20 kg steel block on a ...

el
tabletop. A child attempting to use the spring to pull the block directly horizontally from rest
extends the spring by 30.0 cm
a) Does the block slip? Explicitly state how you know.
b) Calculate the magnitude of the acceleration if the block accelerates or, if it does not, calculate
the magnitude of the static frictional force acting on the block.

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n, I completed parts A and B, but can't get C. We get all the answers to the questions but not how to get to the answer. The question is:
Patrick changes velocity from 2.0 m/s North to 4.0 m/s South with an acceleration of 0.50 m/s/s South. (A) Determine how much time this process takes (ANSWER: 12 s). (B) Find his displacement (magnitude and direction) (ANSWER: 12 m South). (C) Find how much distance Patrick covered (ANSWER: 20 m).
Another question I was having trouble with was this (I got part A but not parts B or C):
Two cars are traveling along a straight line in the same direction, the lead car at 25.0 m/s and the other car at 30.0 m/s. At the moment the cars are 40.0 m apart, the lead driver applies the brakes, causing his car to have an acceleration of -2.00 m/s/s. (A) How long does it take for the lead car to stop? (ANSWER: 12.5 s). (B) Assuming that the chasing car brakes at the same time as the lead car, what must be the chasing car's minimum negative acceleration so as not to hit the lead car? (ANSWER: -2.29 m/s/s). (C) How long does it take for the chasing car to stop? (ANSWER: 13.1 s).

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16.Mary wants to throw a can straight up into the air and then hit it with a second can. She ...

collision to occur at height h = 5.0 m above the throw point. In addition, she knows that she needs t1 = 4.0 s between successive throws. Assume that she throws both cans with the same speed. Take g to be 9.81 m/s2.
(a) How long it takes (in seconds) after the ﬁrst can has been thrown into the air for the two cans to collide? Answer to 4 signiﬁcant ﬁgures. (b) Find the initial speed of the cans (in meters/second) to 4 signiﬁcant ﬁgures.

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ons of acidified potassium dichromate from a stock solution of 0.010M K2Cr2O7in 2.0 M H2SO4with the concentrations
0.0008 M,
0.0016 M,
0.0024M,
0.0032 M and
0.0040 M.
How do I go about calculating this?

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ow. I'm not sure how to calculate this.
Prepare five 25mL solutions of acidified potassium dichromate from a stock solution of 0.010M K2Cr2O7in 2.0 M H2SO4 with the concentrations
0.0008 M,
0.0016 M,
0.0024M,
0.0032 M
and 0.0040 M.

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ric acid. Titration of 11.3 mL X with 0.119 M silver nitrate required 78.2 mL of the latter. The resulting precipitate, containing a mixture of Ag2CrO4 and AgCl, was dried and found to weigh 1.420 g. How much 0.142 M sodium hydroxide should be used to neutralize 11.3 mL solution X?

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acid. Titration of 13.6 mL X with 0.139 M silver nitrate required 40.7 mL of the latter. The resulting precipitate, containing a mixture of AgBr and AgI, was dried and found to weigh 1.260 g. How much 0.117 M sodium hydroxide should be used to neutralize 13.6 mL solution X?

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is filled, the ferris wheel moves around so that the next seat can be filled. Once all seats are filled, the ride begins and lasts for 6 minutes. The height, h m, of Isobel’s seat above the ground t seconds after the ride has begun is given by h=19 sin〖(15t-60)〗+20.5
I dont know how to determine whether to utilise radians or degrees when solving elements of this problem

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22.A quarterback throws a football. The height, h metres, of the ball is given by the equation h = −5t2 ...

t2 + 20t +2 where t is the time in seconds after the ball is thrown.
a) Graph the equation using desmos (if you can take a screen shot of it and include it)
b) Why do we use only positive values of h and t?
c) What is the height of the ball 1 second after it is thrown?
d) What is the maximum height of the ball?
e) How long does it take for the ball to reach the maximum height?
f) For how long is the ball more than 10 m above the ground?

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23.A 4.0-kg block is lowered down a 37° incline a distance of 5.0 m from point A to point B. ...

tal force (F = 10 N) is applied to the block between A and B as shown in the figure. The kinetic energy of the block at A is 10 J and at B it is 20 J. How much work is done on the block by the force of friction between A and B?

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s a blood transfusion through a blood bag. If their venous pressure is 6 mm Hg, how high would the bag need to be held above their arm to facilitate the transfusion?
(g = 9.8 m s-2, Density of blood = 1059 kg m-3, density of mercury = 13,600 kg m-3)

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high would the bag need to be held above their arm to facilitate the transfusion?
(g = 9.8 m s-2, Density of blood = 1059 kg m-3, density of mercury = 13,600 kg m-3)

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26.You design a triangular garden for a park. One side of the garden has a length 60 m and another ...

has length 80 m. This graph shows how the area of the garden is related to the length of the third side.
a) Describe the relation ship between the length of the third side and the area of the garden
b) How could you use the graph to decide what the length of the third side should be in each situation
bb) you want the area of the garden to be 1500 metersquare
bbb) you want the garden to have the maximum possible area

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27.I was wondering if you could help me step up my chem problems, i'm not sure how to begin ...

estion 1: Draven collected a 1ml sample from a local river. Draven added 99 ml of water to the sample. Draven then took 5 ml of the diluted sample, and determined the 5 ml sample to contained 10 mg of sodium chloride. what is the concentration of sodium chloride in the river?
question 2: how many grams of H2 could be produced when 13 g of H202 decompose?
question 3: how many molecules of carbon dioxide could be produced when 25 ml of a 0.8 M ethanol, c2h60, combusts with 5.18X10^23 molecules of oxygen? the unbalanced equation for the combustion of ethanol is given below:
2ch6O+302-> c02+h20

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28.Must know how to use TI 84 Plus CE calculator and be able to teach that skill without wasting time, ...

or give some complimentary/bonus time while you figure it out, or figure out how to do particular things between sessions instead of during the session
Current topics: understand slope and y-intercept and be able to apply it to equations written using different letters instead of m and b or instead of y and x; parallel, perpendicular line equations; calculate slope/gradient of graphs/sides of shapes/equations; calculate midpoint; calculate distance between two points on a graph; find the equation of a line given a graph or given 2 points; learn the meanings of symbols such as R for real numbers, Z for integers' calculate area of a triangle on a graph
The student is in Kazakhstan and speaks Russian and Kazakh fluently, but is intermediate in English. Please speak with her in English as much as possible, but knowing Russian or Kazakh would be a good bonus that would make you preferable to other tutors all else being about the same, though familiarity with TI calculators or the ability to figure them out is also very important.

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1.AU MAT 120 Systems of Linear Equations and Inequalities Discussion

mathematicsalgebra Physics