# Posts by AMANDA

Total # Posts: 2,546

Chemistry
Using data from the following reactions and applying Hess's law, calculate the heat change for the slow reaction of zinc with water (answer must be in kJ/mol Zn): Zn(s) + 2 H2O(l) ----> Zn^2+(aq) + 2 OH-(aq) + H2(g) (ΔHrxn = ?) H+(aq) + OH-(aq) ----> H2O(l) (&#...

Chemistry
The complete combustion of 1.283g of cinnamaldeyde (C9H8O, one of the compounds in cinnamon) in a bomb calorimeter (Ccalorimeter=3.841 kJ/C) produced an increase in temperature of 130.32 C. Calculate the molar enthalpy of combustion of cinnamaldehydy (delta H comb) (in ...

Chemistry
So q/1.283 = 3841(130.32) I know you have to divide by the molar mass which I found to be 132.169 but Im not sure which number I divide it by.

Chemistry
The complete combustion of 1.283g of cinnamaldeyde (C9H8O, one of the compounds in cinnamon) in a bomb calorimeter (Ccalorimeter=3.841 kJ/C) produced an increase in temperature of 130.32 C. Calculate the molar enthalpy of combustion of cinnamaldehydy (delta H comb) (in ...

Chemistry
Phthalates used as plasticizers in rubber and plastic products are believed to act as hormone mimics in human. The value of deltaHcombustion for dimethylphthalate (C10H10O4) is 4685 kJ/mol. Assume 1.035 g of dimethylphthalate is combusted in a calorimeter whose heat capacity (...

Chemistry
Ok I got the answer!! Thank you!!

Chemistry
Ok, yeah I somehow read that as a label not as part of the equation, so 4685*(1.035/194.21)= 24.97 24.97*1000=24967.69 So then would the final equation be: 24967.69=7.293(Tfinal-20.142) Thank you by the way Im just really struggling with this.

Chemistry
How do you convert 4848.975 to J?

Chemistry
Phthalates used as plasticizers in rubber and plastic products are believed to act as hormone mimics in human. The value of deltaHcombustion for dimethylphthalate (C10H10O4) is 4685 kJ/mol. Assume 1.035 g of dimethylphthalate is combusted in a calorimeter whose heat capacity (...

english
I don't know what this one is. That's why i'm here for help!

english
Which one of the following statements is true for the base forms of verb? A. when the subject of a sentence is singular, add "-s" to the base form. B. Add "to" to the base form to create an adjective. C.Do not use a base form with plural subjects. D.Add &...

english
In this sentence, what is the antecedent of the pronoun it? A. her B. Carla C.house D.work?

english
which sentance contains an incorrect plural? A.The parties ended around midnight. B. If wishes were horses, beggars would ride. C.We spotted the foxs late in afternoon. D.I hate traffic delays.

english
A. river

english
We left King ranch on a december day in 1873. On the Santa Fe trail, we hit bad weather. The Red river was flooded and it took us four days to get the Cattle across. All in all, it was a hard trail drive, but we got our Longhorns to the railroad at Abilene. Which of the ...

Which of the following shound be capitalized? a. river b railroad c drive d weather?

Math
Step 1: Find out what 10 to the 5th power is equal to. it = 100,000 Step 2: Multiply 100,000 by 10 Step 3: your answer = 1,000,000

chemistry
what is the chemical name and lewis structure of NO3 -2

Polynomials
A rock is thrown upward at a speed of 10 metres per second. The height of the rock above the ground is given by the formula h=10t-2.0t². Where h is the height in metres above the ground and t is the time in seconds. Then what is height after 5 second?

chemistry
how are the elements in a pair of isotopes the same? how do they differ? And also if you know anything about the atomic structure phrase apeman i could use some serious help right now i have a test tommoro and i cant remember all the material

chemistry
a new compound composed of just Hex-Nuts and bolts is formed.A 13.7 Kg sample of the new compound is separated into its component elements with the following result 3.84 kg. of hex-nuts and 9.90 kg of bolts. 1. How many hex-nuts are present in the 13.7 kg sample 2. how many ...

bookkeeping
Using your computer, you create a file for an existing costumer. When you're finished, you should a. overwrite the existing file by giving the new file the same name. b. use Save as to save the new file under a different name c. coordinate the old and new files b giving ...

Physics
In a head-on collision, a car stops in 0.14{\rm s} from a speed of 24{\rm m}/{\rm s} . The driver has a mass of 67{\rm kg} , and is, fortunately, tightly strapped into his seat. What force is applied to the driver by his seat belt during that fraction of a second?

math-algebra
one pump can empty a pool in 5 days, wheras a second pump can emtpy pool in 7 days. how long will it take the two pumps, working together, to empty the pool?

chemistry
Would you expect a chemical change to be always accompanied by a physical change?Pls. Explain

chem
Write the complete ionic equation for Cu(NO3(aq)+K2S(aq)and namd write the formula for the spectator ions in this reaction? This is what I got pls. check it: complete ionic equation: Cu^19aq)+K^1(aq)+S^-2(aq)=K^1(aq)+NO3^-1(aq)+Cu2S(s) net ionic equation: Cu(aq)+s^-2(aq)=Cu2S(...

math
Number 6 is actually ( -8, -10). I took the mother F***ing test and got that answer wrong because of you guys.

Chemistry
a student conducts and experiment by reacting 39.6g CuSO4 with an excess of MgS. The reaction yields 9.5599g CuS. What is the percentage yield? MgS+CuSO4=CuS+MgSO4

Geometry
Find the measure of each angle in a triangle with angles: x, (x-135), and 1/10 x

chemistry
A 27.00 mL sample of an unknown H3PO4 solution is titrated with a 0.110 M NaOH solution. The equivalence point is reached when 25.78 mL of NaOH solution is added. What is the concentration of the unknown H3PO4 solution? The neutralization reaction is: H3PO4(aq) + 3NaOH(aq) -&...

science
fill in the blank:the ____, the force acting on an object, the greater the acceleration of the object. It is 6 letters and the third letter is R

math
A student take in 2,300 calories and burns 2,500 calories. find the net change

Algebra
In 2007, Donald's stock portfolio decreased in value by 25%. In 2008, his stock portfolio decreased in value by another 40%. What percentage gain is required in 2009 for Donald's stock portfolio to return to the value it had in the beginning of 2007? (Round to nearest ...

english

Algebra
Find the distance between the points and the midpoint of the line segment joining them (p,0) (q,0)

Algebra
In which quadrants are the sign of first and second coordinates different

Algebra
Find x such that point (x,9) is 10 units from (9,3)

Geometry
if EF=2x-10 FG=3x-9, and EG=21 find the value of x, EF, and FG

Chemistry
Okay, I think I got it! Thanks a bunch :)

Chemistry
I have this problem.... Hexane has a density of 0.659 g/ml. How many milliliters (mL) would a student need to pour in order to get 49.5 g of hexane? Am I to solve by using mass = density x volume? And if so, is the answer 32.62mL?

i don't understand this math
4 is A those of u who think its c are wrong

Algebra 2
2x-y+=-9 3x-8y=-7 using the substitution method.

AP Physics
The volume of liquid flowing per second is called the volume flow rate "Q" and has the dimensions of [L]^3/[T]. The flow rate of a liquid through a hypodermic needle during an injection can be estimated with the following equation. Q = pi * R^n (P2 - P1) / 8ηL ...

math
500 becuase it takes away a hundred mph with the aerodynamicness

Theory to Practice
it would be b because it is one of the biggest obsticles as a begginner

mr sus
it will show the teacher that you have fully grasped the entire concept of what has been taught to you.

Economics
what exactly ?

Chem
What is 1250.37986 with 3 significant figures?

Physics
(a) Find the capacitance of a parallel-plate capacitor made of two 5 cm×5 cm square plates separated by 1 mm. (b) If 50 V is applied to this capacitor, how much energy is stored?

Physics
Three positive particles of charges 1 μC, 2 μC, 3 μC, and 4 μC, are located at the corners of a square of side 1 cm. Calculate the potential in the center of the square, taking V = 0 at a great distance.

Physics
How much work does the electric field do in moving a 2 μC charge from a point with a potential of +20 V to a point with a potential of −20 V?

Never mind I figured it out the answer is 67.3614 if anyone needs help

A race car is one lap behind the lead race car when the lead car has 57 laps to go in a race. If the speed of the lead car is 66.2 m/s, what must be the average speed of the second car to catch the lead car just before the end of the race (i.e., right at the ﬁnish line...

physics
Tammy leaves the oﬃce, drives 43 km due north, then turns onto a second highway and continues in a direction of 30◦ north of east for 80 km. What is her total displacement from the office? and At what angle is her displacement? (Consider east to be 0◦ and ...

Math/Chemistry PLS HELP
Find the absolute and percent relative uncertainty and express each answer with a reasonable amount of significant figures. 9.2(+ or -0.7)*(0.0054(+-0.3)+0.0056(+-0.7) The Algebraic answer: 0.1012 Absolute error? Relative error %?

Health
The answer is A. Added sugars are sugars and syrups that are added to foods or beverages when they are processed or prepared. This does not include naturally occurring sugars such as those in milk and fruits.

Chemistry 314
Five mineral samples of equal mass of calcite, CaCO3 (MM 100.085) , had a total mass of 12.4 ± 0.1 g. What is the average mass of calcium in each sample? (Assume that the relative uncertainties in atomic mass are small compared the uncertainty of the total mass.) (Input...

chemistry
A volume of 29.62 ± 0.05 mL of HNO3 solution was required for complete reaction with 0.8896 ± 0.0008 g of Na2CO3, (FM 105.988 ± 0.001). Find the molarity of the HNO3 and its absolute uncertainty. I have the molarity of HNO3 = 0.5667

Chemistry
A volume of 29.62 ± 0.05 mL of HNO3 solution was required for complete reaction with 0.8896 ± 0.0008 g of Na2CO3, (FM 105.988 ± 0.001). Find the molarity of the HNO3 and its absolute uncertainty. I have the molarity of HNO3 = 0.5667

Chemistry
Five mineral samples of equal mass of calcite, CaCO3 (MM 100.085) , had a total mass of 12.4 ± 0.1 g. What is the average mass of calcium in each sample? (Assume that the relative uncertainties in atomic mass are small compared the uncertainty of the total mass.) (Input...

calculus 1
THANK YOU!!!!!

calculus 1
If you can program a calculator or computer, estimate the length of the curve f(x) on the given interval using largest n's. f(x)=56cos(x), for x is greater than/equal to 0 and x is smaller than/equal to pi/2.

Chemistry 314
What NaCl concentration results when 254 mL of an 0.880 M NaCl solution is mixed with 412 mL of a 0.450 M NaCl solution?

Chemistry
I figured it out thanks to related questions.

Chemistry
75.0 mL of a 1.80 M solution is diluted to a volume of 258 mL. A 129-mL portion of that solution is diluted using 187 mL of water. What is the final concentration?

Chemistry
75.0 mL of a 1.80 M solution is diluted to a volume of 258 mL. A 129-mL portion of that solution is diluted using 187 mL of water. What is the final concentration?

Structured English Immersion
How can the continuum of strategies be used inappropriately in the classroom?

algebra 2
Tickets for the hamiltons high school's summer play are $3 for students and$5 for non-students. on opening night 937 tickets were sold and $3943 is collected. How many tickets were sold to students? non-students? geography A stream has jumped its banks and is starting to flow through a formerly dry prairie. Trees are beginning to take root near the riverbed and are starting to develop a canopy. Explain what you believe will happen to the native grass that has flourished in this spot up until now... math You have an aquarium for your new pet, “Shamu” the killer whale, that contains 100,000 pounds of ocean water with a salinity of 30 o/oo. a. Calculate how many pounds of salt are currently in the aquarium. b. You think Shamu may be allergic to salt, so you decide to ... Social Studies YES FOR SURE Science How gravitational acceleration is used to benefit mankind and the environment. How can rural people also benefit from thr use of gravitational acceleration? Health Its d. Reduce daily sodium intake to less than 2,300 milligrams (mg) and further reduce intake to 1,500 mg among persons who are 51 and older and those of any age who are African American or have hypertension, diabetes, or chronic kidney disease. Hea;th The answer is D. Currently, many of the foods and beverages Americans eat and drink contain empty calories – calories from solid fats and/or added sugars. Solid fats and added sugars add calories to the food but few or no nutrients. SPANISH Change the following constructions to an adjetivo posesivo and noun according to the example: Example: la mesa de ella su mesa 1. el gato de Juan y María 2. las sillas de ti 3. el hermano de mí 4. la computadora de tu y yo 5. la mesa de usted 6. la mesa de ... design Have I the write answer so far? 1a 2b 3b 4b 5c 6d 7D 8d chemistry What is the molarity of a solution containing 18.0 g of KCl in 354 mL of solution? Principles of Management - Strategic Management please review my answers! 1. which of the following is an example of an internal stakeholder of an organization? A) distributors B) suppliers C) Unions D) Individual Workers It is: D) Individual Workers 2. Two drug companies agree to work together to pool their research and ... Writeacher maybe you can help ? Principles of Management - Effective Management Are you a business expert? I saw your responses under the business catagory? Principles of Management - Effective Management Do you know of a Business Expert on here that could also double check my work? MS. SUE HELP! Principles of Management - Effective Management I am trying to enter the corse work today, please help! Principles of Management - Effective Management Please double check my answers please! 1. a team manager is resolving the conflicts that exist among the members of his team in an organization. this is an example of: a. planning b. organizing c. leading d. controlling answer C 2. a manager at a grocery store is trying to ... College Math Write the mixed number as an imprper fraction. 7 1/9 = A. 64/9 b. 22/3 c. 7/1 d. 65/9 I think the answer is A. math If the graph x squared + y squared = c contains the point (-3,5), then c = ? Math A line segment begins at point (3,4) and has a length of 13 units. What are the possible endpoints of this line segment? Math the perimeter of an equilateral triangle is 50 inches longer than the length of one side. What is the length of one of the sides? chemistry how many grams of c2h6o contain the same number of oxygen atoms as 0.75 mol of h2o? Math Find how much interest$15,000 earns in 4 years in a certificate of deposit paying 8.5% interest compounded quarterly.

vocabulary

physics
A rock is tossed straight up with a speed of 29m/s. When it returns, it falls into a hole 13m deep. Solve for rock's velocity as it hits the bottom of the hole. &How long is the rock in the air, from the instant it is released until it hits the bottom of the hole?

child care
be able to acquire most of your equipment from free and inexpensive sources

Physics
A sheet of siding has a centrally-located doorway of width 2.0 m and height 6.0 m cut out of it. The sheet, with the doorway hole, has a mass of 264 kg. (a) What is the x coordinate of the center of mass? (b) What is the y coordinate of the center of mass? Assume the lower ...

Busniess English - Negative and Persuasive Message
Which sentence presents an alternative in appropriate way? a. "The 11 a.m. flight is completely sold out, so I booked you on the 2 p.m. flight. Hopefully that will work for you." b. "We are out of the red units, so we went ahead and shipped you 12 green ones ...

Thank you so MUCH!

Indicate the alternative that both correctly evaluates the following sentence and correctly explains the reason for the evaluation. "As soon as you provide your date of birth on Line 2, your application for a flexible spending account will be processed." a. Good ...

Business English - WRiting to build goodwill
C. Main idea(s), background information, negative elements, benefits, goodwill ending.

Business English - WRiting to build goodwill
4. A 11. C 19. B

Business English - WRiting to build goodwill
Can someone double check my answers? 1. Which way of askin for action carries the highest level of politeness? A. a polite order B. an indirect request c. a question d. an order answer is: c. a question 2. Which of the following statements most effectively applies you-attitude...