Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this. 2x + 10y = 58 -14x + 8y = 140

92,096 questions, page 594
1. CHEMISTRY!!!=0

Determine pH of each solution: b) 0.20 M CH3NH3I I did.... CH3NH3^+ +H2O -> CH3NH2 + H3O^+ 0.20 ---------------0--------------0 0.20-x--------------x------------x so i got... ? =x^2/0.20-x i looked up in the back of the book and found the Kb of CH3NH2 to

asked by ALISON on March 1, 2012
2. Chemistry

Assuming the solution you used was 95% ethanol by volume and that the density of ethanol is 0.816g/mL, how much water and carbon dioxide are produced in the experiment? Equation: C2H6O+3O2-->2CO2+3H2O

asked by BUTCHER on April 19, 2016
3. chemistry

calculate the volume of concetrated nitric acid (68%) that is neede to prepare stock solution 0.25M in 1000mL volumetric flask.(dnitric acid=1.513g/cm3)

asked by farah on July 12, 2013
4. Chemistry

If one assumes the volumes are additive, what is the concentration, in mol/L, of NO3− in a solution obtained by mixing 263 mL of 0.167 M KNO3, 311 mL of 0.404 M Mg(NO3)2, and 713 mL of H2O?

asked by Wes on October 8, 2014
5. general chem

A certain monoprotic weak acid with Ka = 0.49 can be used in various industrial processes. (a) What is the [H+] for a 0.191 M aqueous solution of this acid and (b) what is its pH? Round the [H+] to three significant figures and the pH to two places past

asked by Bri on March 25, 2012
6. science

Calculate the pH of a solution created by mixing 200.0 mL of 0.400 M acetic acid and 200.0 mL of 1.00 M sodium acetate. Hint: The instant the two solutions are mixed what are the initial concentrations of each?

asked by Bruce on February 14, 2011
7. Chemistry

Why did we have to use the same thermometer for finding, the freezing point of both, solvent and solution? If your thermometer was not calibrated (reading 0.05 degrees Celsius below the correct temperature), how would this effect your measured value of

asked by G on March 14, 2011
8. Chemistry

A 75.0g sample of liquid contains 17.5% by mass of H3PO4 (molar mass=98.0g/mol). If 215.0mL of Ba(OH)2 is needed to completely neutralized the acid, determine the concentration (or molarity) of the Ba(OH)2 solution used.

asked by Atia on July 20, 2019
9. chemistry

determine the mass of a 50.0mL sample of your salt solution. Report the mass as a number and use all lower case letters to spell out the word(s) in the unit(s). y = 1.049 x + 0.096

asked by Elias on May 28, 2012
10. Chemistry

A solution of K2CrO4 was titrated with AgNO3, using a silver indicator electrode (E=0.799V) and a S.C.E. electrode (E=0.241V). The product, Ag2CrO4, has a Ksp = 1.1x10^-12. What is the potential at the equivalence point?

asked by Jeanie on May 28, 2012
11. chemistry

When the following redox equation is balanced with smallest whole number coefficients, the coefficient for the hydrogen sulfate (HSO4-) ion will be ______ . Al + HSO4- + OH- --> Al2O3 + S2- + H2O (basic solution)

asked by Admir on March 26, 2012
12. Chemistry

Explain with a chemical equation why the pH of the salt solution is or is not the same as pure water: NaCl, NaC2H3O2, NH4Cl We're working with salt and buffer solutions but the equations confuse me the most. Anything helps!!

asked by ryancon on October 3, 2018
13. Chemistry

A solution of 4-methyl-3-penten-2-one in ethanol shows an absorbance of 0.52 at 236 nm in a cell with a 1-cm light path. Its molar absorptivity in ethanol at that wavelength is 12,600 M^-1 cm^-1. What is the concentration of the compound?

asked by Ryan on February 11, 2015
14. Chemistry

A solution of 4-methyl-3-penten-2-one in ethanol shows an absorbance of 0.52 at 236 nm in a cell with a 1-cm light path. Its molar absorptivity in ethanol at that wavelength is 12,600 M^-1 cm^-1. What is the concentration of the compound?

asked by Ryan on February 11, 2015
15. Chemistry university level

what mass of ethylene glycol, the main component, of antifreeze, must be added to 10.0 L water to produce a solution for use in a car's radiator that freezes at -23.3 degree C? Assume the density for water is exactly 1 g/ml.

asked by Raj on January 27, 2009
16. chemistry

What mass of solid sodium formate (of MW 68.01) must be added to 115 mL of 0.57 mol/L formic acid (HCOOH) to make a buffer solution having a pH of 4.16? Ka = 0.00018 for HCOOH. Answer in units of g

asked by Anonymous on January 31, 2015
17. CHEMISTRY!

what mass of ethylene glycol C2H6O2 the main component of anitfreeze, must be added to 10.0L water to produce a solution for use in a car's radiator that freezes at -23.3°C. Assume the density for water is exactly 1 g/m.L

asked by - on January 27, 2009
18. chemistry

A solution was made by dissolving 10.0g of a nonvolatile nonelectrolyte compound in 100.0g of water froze at -0.93C. What is the approximate molecular weight of the substance. (for water..kf=1.86C/m) (m is molality)

asked by Drew on December 12, 2011
19. general chem

A certain monoprotic weak acid with Ka = 0.49 can be used in various industrial processes. (a) What is the [H+] for a 0.191 M aqueous solution of this acid and (b) what is its pH? Round the [H+] to three significant figures and the pH to two places past

asked by Bri on March 25, 2012
20. chemistry

Calculate the oxalic acid mass required for neutralization of 25 ML of 0.1 M NaOH solution.Dihydrate Organic Diacid (H2C2O4.2 H2O, molar mass = 126.04 g/mol)

asked by wallace on August 23, 2018
21. English

Word box: I have Intimidate liberate logical misrepresent optional and variable left 10. her arguement was so ______ that she convinced us that her solution to the math problem was the correct one logicaL?

asked by Jerald on January 22, 2013
22. Chemistry

Calculate the freezing of solution of 3.46 g of compound,X, in 160 g of benzen.when separated sample of X was vaporised, it density 3.27 g/L at 116 c and 773 torr. The freezing point of pure benzene is 5.45 c and Kf is 5.12 c/m.

asked by Ethio on November 8, 2011
23. Science

AIM.will THE colour OF IODINE SOLUTION change TO BLUE-BLACK WHEN WE ADD THE STARCH POWDER ON IT? 1.LIST TWO PLANNING STEP FOR THIS INVESTIGATION. 3 .formulate THE HYPOTHESIS FOR THIS INVESTIGATION.

asked by Lindokuhle on March 27, 2018
24. Chemistry

assuming complete dissociation of the solute, how many grams of KNO3 must be added to 275 mL of water to produce a solution that freezes at -14.5 C? The freezing point for pure water is 0.0 C and is equal to 1.86 C/m .

asked by Colin on January 27, 2012
25. Chemistry 104

A student has 10.0mL of phosphate solution that contains 1.0M PO4{3-}.The Student reacts this with excess ammonium & magnesium under basic conditions to produce 2.2034g of struvite. Calculate the % yield.

asked by Samantha on October 2, 2014
26. Chemistry

0.400 g of a solid base X(OH)2 was dissolved in 50.0 mL of water. The solution was neutralized with 65.80 mL of 0.150 mol/L HCl. Calculate the molar mass of the base. Do I need to set up a dilution equation? I'm not sure what to do.

asked by Anon on December 2, 2015
27. College of Medicine ;University of Malawi

what is the ph at 25 degrees Celsius of a solution made by dissolving a 5.00 grain tablet of aspirin in 0.500 litres of water? The tablet contains 0.325g of the acid HC9H7O4. ka=3.3*10^-4mm=180.2g/l

asked by Andrew on December 3, 2015
28. Chemistry

I need major help with this problem! especially with the first equation that is used... A buffer is prepared by adding 115 mL of 0.20M NH3 to 145 mL of .15M NH4NO3. What is the pH of the final solution? Use the Henderson-Hasslebalch equation.

asked by Rachel on March 28, 2007
29. Physic

A spherical concave mirroe has a radius =0.4m forms an image of a 0.2 m high object located 1m from the vertex of mirror. find the position and height of the image. ? please explain your solution

asked by mac on December 12, 2010
30. Civics

Which of the following statements is most likely to have been said by an Anti-federalist? The constitution is the best solution to the country's problems. This new government will be too powerful. I don't like it.*** A stronger national government will

asked by jeje on January 19, 2015
31. General Chemistry

A solution of 2.50g of compound having the empirical formula C6H5P in 25.0g of benzene is observed to freeze at 4.3 degrees Celsius. Calculate the molar mass of the solute and its molecular formula.

asked by Sasha on September 4, 2011
32. microbiology

In a solution, the substance present in the largest amount is referred to as the solvent. Consider adding one ounce of oil to one gallon of water. Using terms, such as solute, solvent, polar, non-pola

asked by doug on January 25, 2011
33. Chemistry

In a titration of 26.0 mL of 0.840 M H2SO4, __________ mL of a 0.200 M KOH solution is required for neutralization. Express your answer to the nearest 1/10 mL. Hint: remember H2SO4 is a diprotic acid

asked by Camarra on March 10, 2010
34. General Chemistry

how many grams of a protein weighing 4500 grams/ mol must be present in 100 ml of water solution to a given osmotic pressure of 18 mm hg at 25 degrees celcius...( use formula of pie = Mrt

asked by Sarah on December 11, 2010
35. chemistry

If the end point in the titration of oxalic acid with NaOH solution is super-passed (too pink), will the molar concentration of NaOH be hiegher or lower than the actual value ? Explain ..

asked by Huda on April 2, 2011
36. Chemistry

A weak acid HA (pka=6.00) was titrated with 1.00M NaOh. The acid solution had a volume of 100ml and a concentration of .100M. Find the pH at the following volumes of added base. Vb=20ml

asked by Layla on April 25, 2016
37. Chemistry

A student dissolved the KHP in 100.0mL of water instead of 50.0mL. Will the molar concentration of the NaOH solution determined from titrating be greater, less than, or unaffected by this mistake? Explain.

asked by Lola on April 2, 2013
38. chemistry

0.1276 of a monoprotic acid (molar mass 110g/mol) was dissolved in 25ml of water.The pH of the solution was found to be 5.87 after the addition of 10.0ml of 0.0633 M NaOH.The Ka of acid is.......................

asked by tete on April 18, 2010
39. fluid mechanics problems

With the distance: 0.610 m, nutrient solution (ρ = 1040 kg/m3) can just barely enter the blood in the vein. What is the gauge pressure of the venous blood? Express your answer in millimeters of mercury.

asked by Gun-yuoung on November 30, 2008
40. chemistry

Calculate the pH and pOH of each of the following aqueous solutions of strong acd or base: (a) 0.010 M HNO3(aq) (b) ) 1.0 x 10-3M Ba(OH)2(aq) (c) 10.0 mL of 0.22M KOH(aq) after dilution to 250 mL (d) 100 mL aqueous solution containing 050 g of Ba(OH)2 (aq)

asked by imelda on September 16, 2014
41. Chemistry

Suppose 10.2 G of copper a state is dissolved in 350 mL of a 3-0 molality solution of sodium chromate calculate the final molarity of copper assume the volume stays constant

asked by Sabrina on April 13, 2019
42. chemistry

How many grams of HCOOH are needed to make 3.7 liters of aqueous solution of pH=3.5? I have followed the steps for a similar problem posted;I found x to 3.16e-4 mol/L but I'm having trouble converting it to grams.

asked by nick on October 6, 2010
43. Human Physiology

A subject with a body weight of 60 kg was injected with 10 ml of a 1% (w/v) solution of Evans Blue. After 10 min, the blood was sampled and found to contain 0.035 mg ml^-1 of the dye. What is the subject’s plasma volume in litres?

asked by Dean on November 8, 2010
44. Chemistry

24.0 mL of a 2.4 M silver nitrate is mixed with 32.0 mL of 2.0 M sodium. Calculate the mass of precipitae formed. Calculate the concentration of all ions remaining in solution after the precipitate forms. I don't know how to start this or where to go with

asked by Marissa on April 7, 2015
45. chemistry

What about this question? Calculate the mass (g) of PbSO4 that will dissolve in 2000 mL of 0.0694 M K2SO4 solution. The equation represents the solubility process. PbSO4 (s) Pb2+ (aq) + SO42- (aq) Ksp = 1.7 x 10-8

asked by Confused on October 16, 2010
46. Chemistry

I don't understand how to do this problem. You mix 1.00 L of 2.00 M BaCl2 with 1.00 L of 2.00 M AgNO3. What compounds remain in the solution, and what are their concentrations? BaCl2 + 2AgNO3 ---> 2AgCl + Ba(NO3)2 Is it trying to trick me with the two sets

asked by Ana on April 29, 2010
47. Chemistry

you have 505mL of a .125 M HCl solution and you want to dilute it to exactly .100. How much water should you add? I got (.125M)(505mL)=(.100M)(Vf)= 631.25. But on my answer sheet they got 126 mL of H2O???? I don't know how she got it.

asked by Gracy on October 15, 2011
48. chemistry

Balance each of the following redox reactions occurring in acidic aqueous solution.Express your answer as a chemical equation. Identify all of the phases in your answer. Zn(s) + Na(aq)-> Zn2+(aq)+Na(s) Cl-(aq) + 2NO3-(aq)->NO(g)+Cl2(g)

asked by redgy on April 23, 2011

No one can predict a natural disaster or world crisis, when a hurricane, flood, or a pandemic strikes a country, who is most likely to respond first? Which economicsystem is the best solution to handling a crisis of epic proportion?

asked by Rhonda on October 30, 2010
50. Program Design

You require an algorithm that will receive an integer from the screen, add 5 to it, double it, subtract 7 from it, and display the final number on the screen. Need help with the input, output, and processing. Also with the solution algorithym.

asked by Kemp on September 8, 2008
51. AP Chem

When 0.076 moles of lead(II) nitrate are dis- solved in enough water to make 670 mililiters of solution, what is the molar concentration of nitrate ions? Answer in units of M

asked by Lutesia on October 9, 2011
52. Child Development

1) The recording method that's most useful in discovering the causes or results of a child's behavior is A. rating scale. ￼B. time sampling. C. event sampling. D. checklist. 2) One way a teacher can help a child stand up for her rights is A. making other

asked by Danielle on December 4, 2014
53. physics

A ballistics pendulum is a device used to measure the speed of a fast moving projectile such as a bullet. A bullet of mass 5g is fired into a large block of wood of mass 1.5kg suspended from some light wires. The bullet is stopped by the block and the

asked by ZU on August 25, 2013
54. anthropology

When individuals get married, alliances are formed between the two families. In some cultures there will also be a formal economic exchange. Three forms discussed in this chapter are bridewealth, bride service and dowry. Discuss each economic form with its

asked by jimmy on January 26, 2015
55. Science

The following sphere is responsible for forming the solid shell of Earth that holds up life? -Hydrosphere -Lithosphere -Atmosphere -Biosphere** Explain the interaction between the four main components of Earth's physical systems. Be sure to include the

asked by PoPo on March 13, 2017
56. Civics

Why did the framers of the constitution include the system of checks and balances? To ensure the powers of each branch of government are limited and checked by another branch To create a process for the American people to choose their representatives for

asked by jeje on January 6, 2015
57. Math [Calculus]

I'm asked to find the volume of the solid bounded by the curves x=1+y^2 and y=x-3, rotated about the y-axis. I have a general idea of how to start the problem off, but I'm not sure how to find the interval that I need to work with...

asked by Tii on January 10, 2010
58. English

I am doing the 4 humours for english home work and have to give examples of characters from tv, film or book that match the 4 humours so melancholy, phlegm, sanguine and choler.

asked by Anonymous on November 16, 2011
59. Physics

A dram of mass 100kg is rolled into the deck of long 1.5m above a horizontally floor using a plank 4m long.calculate the work done against gravity during the process [Take g=10ms'2]

asked by Yegh margaret on January 29, 2017
60. English

Wolunteering at an orphanage. I have worked at an orphanage. There were a lot of work to do. I talked with children there and helped them with math. I taught them English, too. I was happy because I could help others. (Would you check the passage above?)

asked by rfvv on October 15, 2010
61. Busienss

Hello My name is Sara and i,m work in marketing and i have get offer from some company from all world about some product for import and export and i do like to know how i can check this company its real or fake wait your reply Thanks

asked by saramazen on June 12, 2014
62. Physics

A certain coiled spring with an unstretched length of 20cm required a force of 2N to stretch it by 0.2cm. What work is done in stretching it by 2cm if the elastic limit is not exceeded?

asked by Nina on October 2, 2018
63. Maths

A rock, R, is 40 km from a harbour, H, on a bearing of 040°. A port, P, is 30 km from R on a bearing of 130°. Draw a sketch showing the points H, R and P and work out the size of angle HRP.

asked by Sam on September 14, 2011
64. Math

How many square tiles with sides 1ft long on each edge would be needed to cover the floor of an 8 by 13ft room? Work Multiply 13ft by 8ft?

asked by Need help desperately on October 20, 2015
65. physics

a loaded cart as a total mass of 227kg.if a 312-N force acting at angle of 30° to the ground is applied, how much work is done in moving the cart 15 meters?

asked by leonardo magdayo on January 18, 2012
66. physics

A 58.0-kg skier starts from rest at the top of a ski slope of height 70.0 .If frictional forces do −1.09×104 of work on her as she descends, how fast is she going at the bottom of the slope?

asked by lok on December 14, 2011
67. Physical Chemistry

Derive an expression for number of electrons N(E) with energy that can escape from a metal in terms of Z(E) (density of state) and F(E) (Fermi-dirac function) and ф (work function).

asked by John on November 18, 2011
68. Math

Czarina is working part time at a pastry shop baking cupcakes. If she works for 30 hours in one week on the average, how many hours a day does she work?

asked by Molly on October 17, 2012

Compute the difference between the ordinary interest and the exact interest for a loan with a principle amount of \$1100 at 12 percent for 120 days. I'm getting \$0.60 Can you check my work?

asked by Casey on February 21, 2015
70. English

Please check my work. Identify whether if this sentence is complex, an exclamation, declarative, or interrogative. The car broke down, but a rescuer van arrived within minutes. ----- Complex

asked by Priya on July 20, 2011

Give an example of how each of following management structures affects the day-to-day work of an organization? 1) Departmentalization 2) Matrix Organizations 3) The project Team 4) The Collegial Model

asked by Anonymous on March 16, 2007

My questin is If r=5z then 15z=3y, then r= I just can't seem to determine how to set this problem up. I tried subsutition but that doesn't work for me either? Thanks in advance I assume you want to define r in terms of y. If r = 5z, then 3r = 15z.

asked by Katie on March 5, 2007
73. physics

A sled if pulled over level snow a distance of 0.500 km by a force of 124 n applied to a rope that makes an angle of 35.0 degrees with the snow. How much work is done?

asked by mer on January 29, 2008
74. scholarship thing

for the scholarship, it says we can submit additional work that would give evidence to why we would excel in an honors program. i would really like to submit some photos i took but i'm not sure that would help me, especially when i plan on majoring in

asked by lillian on January 1, 2009
75. p.e

You think your friend is depressed and may be considering suicide. Which of the following actions should you avoid? A. Tell him how concerned you are about him; you'll probably embarrass him. B. Leave him alone to work it out. C. Tell an adult you trust

asked by Beau on September 19, 2014
76. world lit

cervantes wrote a parody while voltaires wrote a satire. explain the difference in purpose between the two forms of writing, then use two examples from each work to support your statement.

asked by jarod on August 25, 2011
77. U.S History

In the Revolutionary war, who helped America to some early wins, but turned traitor later on in the war? Just a minute! Are you asking us all your questions? What have YOU done to find the answers? We HELP but don't DO the work for you!

asked by COOL on January 22, 2007

Using requirements of Value Chain Management put these requirements to work specifically at the Smart Chips Company in order to help it remain competitive in the long run.

asked by Jennifer on July 7, 2010
79. geometry

T is the set of all positive numbers n such that n

asked by marco on January 31, 2007
80. Maths

A rock, R, is 40 km from a harbour, H, on a bearing of 040°. A port, P, is 30 km from R on a bearing of 130°. Draw a sketch showing the points H, R and P and work out the size of angle HRP.

asked by Sam on September 14, 2011
81. physics

when 1240 J of heat are added to one mole of an ideal monatomic gas its temperature increases from 273K to 277K. Find the work done by the gas during the process.

asked by tired on November 12, 2013
82. Physica

a man pushes a box of mass 5 kg in a horizontal direction by 10 N force on the surface through a distance of 5m if the cofficien of kinetic friction is 0.2 the total work done on the box is

asked by 1999999 on July 17, 2012
83. physics

a certain coiled spring with an unstretched length of 20cm require a force of 2N to stretch it by 0.2cm. What is the work done in stretching it by 2cm. If the elastic limit is nt execeed.

asked by Anonymous on January 26, 2017
84. physics

"A projectile is fired horizontally at 14.9 m/s from the edge of a 7.05-m-high cliff and strikes the ground. Find the horizontal distance the projectile traveled." I have no work cause I have no idea how to do this...

asked by hailey on September 21, 2014
85. HCA 220

I have not received my book because of a shipping error on the distributors part and I do not have the diagrams needed for week 8 chapters 8, 9, & 10. I can not complete the assignment without it. Can anyone post the diagrams so I can do the work, I would

asked by Jessicka on August 29, 2010
86. math

A hairstlist schedules 1/4 hour to trim a customers hair and 1/6 hour to style. The hairstylist plans to work 3 1/3 hours each day. How many appointments can she schedule?

asked by sarah on October 19, 2014
87. College Level Physics

A horse pulls a cart with a force of 145 newtons at an angle of 30 degrees above the horizontal and moves along at a speed of 2.5 m/s. How much work to the nearest kJ does the force do in 6 minutes?

asked by Devin on June 9, 2013
88. i need your help please :(

a loaded cart as a total mass of 227kg.if a 312-N force acting at angle of 30° to the ground is applied, how much work is done in moving the cart 15 meters?

asked by i need your help please :( on January 18, 2012
89. English

Which of the following is correct when analyzing a story? ignore internal inconsistencies resist the obvious meaning of the work ignore ambiguities do not read skeptically my answer D

asked by christopher on April 23, 2010
90. Economics

suppose you have a factory that makes pens and the demand for the pens decline, and there are more people willing to work due to a recession. does this result in an increase in supply? please explain

asked by Anonymous on October 18, 2007
91. computers

How does organization culture play a role in the successful reliance on the JAD process to identify and gather business requirements? Would JAD work in your company? Why or why not?

asked by Anonymous on August 26, 2010
92. Employees

Proportion practice: "Fancy factory has 300 employees with a 3 to 7 ratio of men to women. How many men work there?" I've been working on this forever. And I can't figure out what to do. DX uarrghhh. Help?

asked by Kiki on November 17, 2008
93. English language

Please tell me how to write these, if you have any idea. Let's assume we are all connected by the oceans;can we work together to protect the environment? Write an essay,story or poem on the above topic. It should be about 700 words?

asked by poppy👌🤔 on May 4, 2019
94. Math

Find the missing dimensions for each three-dimensional figure to the nearest tenth given the volume and other dimensions. I'm not understanding the cones too much. r=5in., v = 487in.3 How do I work it, given only the radius

asked by Nia on March 23, 2011
95. physics

If 180 J of work is performed to move four coulombs of charge from the positive plate to the negative plate shown below, what potential difference exists between the plates?

asked by Marcia on January 12, 2012

How much work must be done to accelerate a baton from rest to an angular speed of 7.27 rad/s about its center? Consider the baton to be a uniform rod of length 0.529 m and mass 0.478 kg

asked by Megan on March 10, 2011
97. Physics

a loaded cart has a total mass of 227kg. if a 312N force acting at an angle of 30 to the ground is applied, how much work is done by moving the cart 15m?

asked by Miko on August 20, 2012
98. physics

when 1240 J of heat are added to one mole of an ideal monatomic gas its temperature increases from 273K to 277K. Find the work done by the gas during the process.

asked by tired on November 12, 2013
99. physics

a loaded cart, mass220-kg is pulled across the ground with the force of300n acting at angle 37 degree with the horizontal. how much work is done in moving the cart 20m?

asked by christian on March 20, 2013
100. Math

How many square tiles with sides 1ft long on each edge would be needed to cover the floor of an 8 by 13ft room? Work Multiply 13ft by 8ft?

asked by Anonymous on October 20, 2015