1.The cost of renting a car is $46 /wk plus $0.25 /mi traveled during that week. An equation
...
esent the cost would be y=46+0.25x , where x is the number of miles traveled.
a. What is your cost if you travel 59 mi?
The cost is $
43.26
.
b. If your cost was $66.25 , how many miles were you charged for traveling?
You were charged for traveling
66.51
miles.
c. Suppose you have a maximum of $100 to spend for the car rental. What would be the maximum number of miles you could travel?
The maximum number of miles you could travel is
Number
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3.3A(g) + X(g) → Z(g) ΔH° = -480 kJ/molrxn
The equation shown above represents an exothermic reaction between A(g)
...
reaction between A(g) and X(g). What is the amount of heat released when 10 mol of A(g) reacts with an excess X(g) ?
ΔH
A -236kJ
X -136kJ
Y -167kJ
Using the heats of formation found in the table above, calculate ΔH for the reaction below.
6A(aq) + 7X(g) → 6Y(l)
Y + 2X → 4Z ΔH=-4
A + 3B → 2Z ΔH=-2
A → X +C ΔH=7
Using the thermodynamic data above, determine ΔH for the reaction below.
2C+ 6B → Y
When 0.3 moles of A(s) (4 grams) is dissolved in 12 grams of water at 23°C, the temperature of the water increases to 31°C. The specific heat of water is 4.18 J/g°C.
Calculate ΔH in kJ/mol. Report your answer to 1 decimal place.
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5.AP Chem AB FRQ
Question 1
A sample consisting of 50. mL of 0.400 M solution of the acid, HClO4, is titrated
...
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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6.I am trying to figure out the optimal radius that will give the lowest surface area of a cylinder. I
...
have done the calculus which reveals that the surface area is at a minimum when height is double the radius. I am now trying to find an equation for the relationship between the amount of wasted surface area as a percentage of the minimum surface area and the ratio between height and radius.
If I were to plot it on a graph, the y axis would be the percentage of excess materials needed as a percentage of the minimum possible surface area, and the x axis would be height divided by radius. Since the surface area is minimized when height=2(radius), I know that when x=2, y=0.
The website https://www.datagenetics.com/blog/august12014/index.html explains what I am trying to do quite well and shows the graph below. I am trying to find the equation for this graph, but am unsure how to go about it.
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8.I'm stuck on this problem regarding finding the speed of a cart moving down and then up a slope from
...
rest. The current unit that our teacher has us on so far is centripetal motion, and I can't recall being taught how to solve this. File attached below shows my work so far, I don't necessarily need the work done for me, but I just want to be put on the right track, such as an equation to start with or what I need to look for. The answer I got was clearly incorrect for part a (which is what I need help with), so please help me get going in the right direction.
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9.I have 5 questions I am stuck on. Please help!
1. Enter the correct answer in the box.
Facundo crochets and sells
...
chets and sells baby blankets, b. Each blanket requires 3 skeins of yarn, and the total number of skeins Facundo uses, y, varies directly as the number of blankets he crochets, b.
Write an equation that models this relationship.
2. The weight of an object, w, varies inversely as the square of its distance from the center of Earth, d. When an astronaut stands in a training center on the surface of Earth (3,960 miles from the center), she weighs 155 pounds. To the nearest tenth of a pound, what will be the approximate weight of the astronaut when she is standing on a space station, in orbit 240 miles above the training center?
3. The square of g varies inversely as h. When g = 16, h = 2. What is the value of h when g = 40?
4. The number of days, d, it will take Manny to read a book varies inversely as the number of pages, p, he reads per day. If k is the constant of variation, which equation represents this situation?
5. The battery life for Bruhier’s cell phone is longer when he has fewer apps running. When only one app is running, the battery will last for 16 hours. When four apps are running, the battery will only last for 4 hours.
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11.Hi, I've been trying to figure out what should be the simplest of formulas for over an hour now. Take
...
e a look at this spreadsheet so I can properly explain:
https://docs.google.com/spreadsheets/d/1lEJIPiSZJk9LYUTSA4oeDwyLXCVd18Zdewm6gnjxcXo/edit?usp=sharing
Ok, so for the sake of simplicity We'll just go with row two here. Cell A2 represents the hours worked freelancing, where B2 is for the minutes of the recorded time frame. C2 is the net amount earned in that time. Over in cell N10 I need to figure out an equation using the =SUM() function (treats it as a normal math problem) where it prints the hourly income based on those three integers. I'll admit i was never great at math, but in my defense I've been up since 6 am yesterday (currently 3 pm) and have been running solely on caffiene and nicotine haha... The sheet is editable and I can see any changes you make in realtime. Is there any way you could help me out on this one? It's for a work report type thing.
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15.
For a reducing balance loan what happens when you pay a extra repayments aggressively at the start. How does it
...
rt. How does it make u pay less interest and have less interest:
Vn+1 = 1.00405Vn - 1817.35, Vo= 34400
The term of the loan is 30 years with monthly payment of 1817.35 at an interest rate of 4.86 p.a
Pls tell me the answer regarding this particular equation
Q2) How much of the principal has been repaid? Fv - Vo is this the correct formula
Q3) Superannuation
Something like if u add money without tax why does it benefit your super account
I’m sorry to disturb you but I was hoping you could help as tmrw is my last writing lesson for my sac
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17.I am looking for someone who is used to water resources engineering/fluid dynamics. I have been tasked to design the
...
ed to design the water, wastewater, and stormwater systems for an addition to a building at our university. I have the maps of the existing systems and I am planning to use these existing systems as much as possible to avoid extra work. I have calculated a water demand and fire flow for the building. I believe I have to use mannings equation for the water pipes to determine flow, etc. I am not sure how to deal with the wastewater. I have to use the rational method for stormwater. I have attached a document which explains what I need to do overall. I need help on this ASAP as I have to present it Tuesday evening.
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18.
Value: 1
equation image indicator
a. (x - 2)2(x - 3)2
b. (x2+ 4)(x2+ 9)
c. (x - 2)(x +
...
2)(x - 3)(x + 3)
d. (x2 - 4)(x2+ 9)
Value: 1
The table below shows the cost of purchasing a standard stapler at five office supply stores, A through E. If the median cost of purchasing a standard stapler for these stores was $17.99, which of the following could NOT have been the cost of the stapler for Store A?
staplergraph.jpg
a. $19.95
b. $18.95
c. $16.95
d. $19.25
Value: 1
If equation image indicator then x =
a. 7
b. 1/5
c. 5
d. 1/7
Value: 1
A six−sided die, with sides numbered 1,2, 3,4,5, and 6, is tossed. What is the probability of tossing a number less than three?
a. 1/3
b. 0
c. 1/2
d. 1/4
Value: 1
If 6m + 4 = 8m, then 4m =
a. 6
b. 2
c. 8
d. 4
Value: 1
In the xy-plane, what is the y-intercept of the graph of the equation equation image indicator?
a. 2
b. 4
c. 16
d. There is no y-intercept.
Value: 1
Which of the following equations has both 2 and −4 as solutions?
a. x2 + 6x + 8 = 0
b. x2 - 2x - 8 = 0
c. x2 + 2x - 8 = 0
d. x2 - 2x + 8 = 0
Value: 1
The perimeter of a square is 20 ft. If you increase the length of the square by 2 feet and decrease the width by 1 foot, what is the area, in square feet, of the new figure?
a. 22
b. 28
c. 35
d. 40
Value: 1
(3x-2y4)-3 =
a. equation image indicator
b. equation image indicator
c. equation image indicator
d. equation image indicator
Value: 1
A softball is tossed into the air upward from a first floor balcony. The distance of the ball above the ground at any time is given by the function, distance function.png, where h(t) is the height of the softball above the ground (in feet) and t is the time (in seconds). What was the maximum height, in feet, of the softball above the ground after it was thrown?
a. 28
b. 30
c. 32
d. 34
Value: 1
A group of 100 people, some students and some faculty, attended a museum opening. Each student paid $10 per person for entrance to the museum and each of the faculty paid $25 per person for entrance. If the total paid, for all 100 people, was $1300, how many students attended the museum opening?
a. 20
b. 50
c. 70
d. 80
Value: 1
The ratio of Sam's age to Hank's age is 5 to 3. If the sum of their ages is 24, how old is Hank?
a. 21
b. 15
c. 19
d. 9
Value: 1
In the xy−coordinate plane shown below, point P has coordinates (8, −6). Which of the following is an equation of the line that contains points O and P?
O and P graph.jpg
a. equation image indicator
b. equation image indicator
c. equation image indicator
d. equation image indicator
Value: 1
The variables x and y are inversely proportional, and y = 2 when x = 3. What is the value of y when x = 9?
a. 54
b. 6
c. 2/3
d. 3/2
Value: 1
A farmer has 1235 trees to be planted on a rectangular parcel of land. If there are 24 trees planted in each row and each row must be complete before it is planted, how many trees will be left over after planting?
a. 21
b. 11
c. 0
d. 55
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