# 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

91,718 questions, page 674
1. ## Math

Plz help lisa is painting a fence that is 26 feet long and 7 feet tall. A gallon of paint will cover 350 square feet. Write and solve a proportion to determine how many gallons lisa will need.

asked by Hannah on September 12, 2012
2. ## Chemistry

If the amount of mercury in a polluted lake is 0.4 µg Hg/mL, what is the total mass in kilograms of mercury in the lake? (The lake has a surface area of 100mi^2 and an average depth of 20 ft.) I'll probably be able to solve this once I know what it's

asked by Jack on October 12, 2007
3. ## algebra

A town has a population of 8400 in 1990. Fifteen years later, its population grew to 12500. Determine the average annual growth rate of this town's population. How do i solve this using applications of exponential functions?

asked by Tony on April 10, 2011
4. ## Math

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the

asked by Salman on November 20, 2009
5. ## Calculus

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the

asked by Salman on November 20, 2009
6. ## algebra

You are putting a stone borderof uniform width around a rectangular garden that measures 6 yards by 15 yards. You only have enough stone to cover 100 square yards. How wide should the border be? Solve using the 5 step process.

asked by Warren on September 9, 2010
7. ## Physics

A car drives straight off the edge of a cliff that is 58 m high. The police at the scene of the accident note that the point of impact is 126 m from the base of the cliff. How fast was the car traveling when it went over the cliff? Can someone please

asked by Anonymous on October 20, 2010
8. ## Physics

Suppose a flame of a gas burner stove emits light just like a blackbody.The flame appears blue,emiting most of the light as a wave length of 475 nanometers. what is the temperature of the flame. How do I solve this?

asked by EBS123 on October 21, 2011
9. ## science

If the kinetic energy of a 0.62kg stone is 2.3J at its highest point and 9.4J at its lowest point how do I calculate the height at the highest point. Thanks The difference in KEnergy has to be equal to the change in gravitational PE. mgh = 9.4-2.3

asked by sarah on January 16, 2007
10. ## Maths

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the

asked by Salman on November 20, 2009
11. ## 3rd grade math

front end estimation to estimate the sum...like..436+517= ~~~~~~also we have some problems that say use rounding to estimate the sum...like..236+710=....DO WE DO BOTH OF THESE THE SAME WAY??? solve then estimate??? my child has been out from school for a

asked by Anonymous on October 20, 2010
12. ## Calculus

There is a point (P) on the graph of [x^2+y^2- 136 x + 12 y + 4560 = 0] and a point(Q) on the graph of [(y + 6)^2 = x^3 - 116 x^2 - 417 x + 267460] such that the distance between them is as small as possible. To solve this problem, we let ((x,y) be the

asked by Salman on November 19, 2009
13. ## physics

The mass of the Earth is 5.98 × 1024 kg. A 6.83 kg bowling ball initially at rest is dropped from a height of 2.12 m. The acceleration of gravity is 9.8 m/s^2. What is the speed of the Earth coming up to meet the ball just before the ball hits the ground?

asked by Jazz on January 16, 2017
14. ## Math

ok so i'm kinda sort of confused... I had this for a equation X^2 + 4X - 1 = 0 and then I was like zero??? zero... really zero... hmm... X^2 + 4X - 1 = dy ???????? That zero does represent when Y equals zero correct??? this allows us to solve for X

asked by Kate on January 3, 2010
15. ## TRIG

In a right triangle ABC, C = 90°, b = 380.1 inches and c = 589.1 inches. Solve for all the missing parts using the given information. (Round each answer to one decimal place for side and to two decimal places for angles.) A = ° B = ° a = inches IM lOST!

asked by Anonymous on February 10, 2012
16. ## Calculus

A square is inscribed in a circle. If the area of the circle is 144(pi)cm*squared* --sorry the square root thing isnt showing up. Then the exact perimeter of the square is... I really don't get how to solve this, but the answer is supposed to somehow be

asked by -Untamed- on October 4, 2011
17. ## Calc

Find a cartesian equation for the curve described by the given polar equation. a. r=2 b. r=3sin pheta c.r^2=sin2pheta I don't understand how to solve for this, especially for r squared. Would someone plz explain how o convert to a cartesian equation. any

asked by Jessica on March 26, 2008
18. ## Math

A submarine begins at -125 below sea level. If the submarine travels at 20 feet per minute, how many minutes would it will take the submarine to rise to the surface and then defend to -104 feet? A: 6 1/4 B: 11 2/9 C: 5 1/5 D: 11 9/20 I said C but it was

asked by Reid on October 7, 2014
19. ## government

Which of the following states is a disadvantage for representation in the winner-take-all system? A. A small state that is evenly split between the two major parties. B. A small state that tends to vote heavily for third-party candidates.***? C. A large

asked by dbh on June 5, 2019
20. ## Chemistry

A solution containing 0.100 mol of Na2CO3 and 0.100 mol of NiCl2 is allowed to react. What mass of precipitate forms in this reaction? I think I know how to do it but don't understand. Do I figure out the mass of each of the compounds? HELP please!!!

asked by STAT on February 25, 2013
21. ## chemistry

A 10.0 ml diluted chloride sample required 44.89 ml of 0.01982 M AgNO3 to reach the Fajans end point. how many moles of Cl- ions were present in the sample? What was the concentration of chloride in the diluted solution?

asked by lin on October 8, 2012
22. ## Chem

Ascorbic acid, H2C6H6O6, is a diprotic acide with a K1= 7.9 E-5 and a K2=1.6E-12. In a .005 M aq solution of ascorbic acid which of the following species is present in the lowest concentration. 1. H2O 2. H3O 3. H2C6H6O6 4. HC6H6O6 5. C6H6O6

asked by Confused on April 22, 2008
23. ## chemistry

Automotive antifreeze consists of ethylene glycol, C2H6O2, a nonvolatile electrolyte. Calculate the boiling point and freezing point of a 25.0 mass percent of ethylene glycol in solution.

asked by danielle on January 31, 2010
24. ## Math

Which inequality represents the solution shown on the graph? A number line is shown with a solid blue dot drawn on negative 60 and a blue ray pointing to the right of negative 60. Scott?

asked by Help I need somebody not just anybody on May 15, 2017
25. ## Chemistry

Antifreeze protects a car from freezing and from overheating. Calculate the freezing-point depression of a solution containing exactly 100. g of ethylene glycol (C2H6O2) antifreeze in 0.500 kg of water. Kf of water is: -1.86 C/m.

asked by Sam on March 9, 2019
26. ## Calculus

Using inverse trigonometric functions, find a solution to the equation cos(x)=0.2 in the interval 0â‰¤xâ‰¤4Ï€. Then, use a graph to find all other solutions to this equation in this interval. Enter your answers as a comma separated list. Thank

asked by Rileigh on April 4, 2017
27. ## Chem Hmwrk

Iodine can be prepared by bubbling chlorine gas through an aqueous solution of sodium iodide: 2NaI(aq) + Cl2(g) → I2(s) + 2NaCl(aq) How many grams of sodium iodide are required to produce 98 g of iodine?

asked by Jon on October 11, 2012
28. ## Chemistry

Determine the potential (in V) of an electrochemical cell using a gold electrode and gold (III) [0.0243 M] solution in combination with a manganese/manganese (II) [0.00567 M] half cell How on earth would I do this question? I just know Au(3+) + 3e- = Au

asked by Joe on June 10, 2009
29. ## Chemistry

Two liquids A and B have vapor pressures of 71.3 and 131 mmHg, respectively, at 25 degrees Celsius. What is the total vapor pressure of the ideal solution made up in the following concentrations? 1.00 mole of A and 1.00 mole of B 2.00 moles of A and 5.00

asked by Vivian on December 7, 2012
30. ## chemisty

I have data for titration of a strong base against a strong acid when I added volumes of NaOH 1 mL at a time to 50.00 mL of HCl to see the change in pH. One of the questions says to find the molarity of the HCl solution but how do I do this with the data.

asked by marla on February 6, 2012
31. ## Chemistry

Calculate the pH values and draw the titration curve for the titration of 500 mL of 0.010 M acetic acid (pKa 4.76) with 0.010 MKOH. Calculate the pH of the solution after 490 mL of the titrant have been added.

asked by Samantha on February 5, 2017
32. ## chem

Ascorbic acid, H2C6H6O6, is a diprotic acide with a K1= 7.9 E-5 and a K2=1.6E-12. In a .005 M aq solution of ascorbic acid which of the following species is present in the lowest concentration. 1. H2O 2. H3O+ 3. H2C6H6O6 4. HC6H6O6- 5. C6H6O6-2

asked by bob on May 5, 2011
33. ## Chemistry

Teeth and bones are composed, to a first approximation, of calcium phosphate, Ca3(PO4)2(s). The Ksp for this salt is 1.3 10-32 at 25°C. Calculate the concentration of calcium ion in a saturated solution of Ca3(PO4)2. Please, help!

asked by Laura on May 9, 2011
34. ## chem

Ascorbic acid, H2C6H6O6, is a diprotic acide with a K1= 7.9 E-5 and a K2=1.6E-12. In a .005 M aq solution of ascorbic acid which of the following species is present in the lowest concentration. 1. H2O 2. H3O+ 3. H2C6H6O6 4. HC6H6O6- 5. C6H6O6-2

asked by bob on May 5, 2011
35. ## Chemistry

Teeth and bones are composed, to a first approximation, of calcium phosphate, Ca3(PO4)2(s). The Ksp for this salt is 1.3*10^-32 at 25°C. Calculate the concentration of calcium ion in a saturated solution of Ca3(PO4)2.

asked by Amy on November 21, 2010
36. ## Chemistry

The freezing point of ethanol is -114.6 deg Celsius and its Kf value is 2.00degC/m. What is the freezing point for a solution prepared by dissolving 50.0g of glycerin in 200g ethanol? I thought it may have been using the formula deltaT=Kf*m, but I'm not

asked by Jonah on February 13, 2013
37. ## chemistry

If a solution is diluted, say by adding 100ml of solvent, does the number of moles of solute change? Does the concentration increase, decrease, or stay the same? i think it depends on what the solvent is, for example if its water then the concentration

asked by david on April 10, 2008
38. ## gen chem

a 10 ml vinegar sample was completely neutralized by 22.5 0.2M NaOH solution . calculate the molarity and percent acetic acid in vinegar I keep getting 2.7% acetic acid is this correct? my friend got 27% and if I am wrong where do you think I messed up?

asked by shannan on November 25, 2012
39. ## Chemistry

Determine the vapor pressure (in atm) of water in an aqueous solution of 12% by mass ethylene group (antifreeze) if the vapor pressure of pure water at that temperature is 0.095 atmospheres.

asked by Samantha on February 15, 2016
40. ## chemistry

Compute the boiling point elevation of a salt water solution that contains 2.60 g of NaCl dissolved in 121 ml of water. Enter the number of degrees celsius that the boiling point will be elevated.

asked by chaddhar on December 10, 2010
41. ## math

A rectangular playground is 800 feet long and 400 feet wide. If fencing costs Php 560 per yard, how much would it cost to place fencing around the playground With solution

asked by ai on September 4, 2014
42. ## Chemistry

When 10.0 g of ammonium nitrate (molar mass= 80 g/mol) are dissolved in 1.00 L of water in a bomb calorimeter with a heat capacity of 2.30 kJ/ K, the temp drops 1.52 K. What is the molar enthalpy of solution of ammonium nitrate?

asked by Sam on October 20, 2012
43. ## chemistry

a 350ml buffer solution is .150M in HF and .150M in NAF. What mass of naoh could this buffer neutralize before ph rises above 4.0? So far I got .285714 from 10^-.544. After that I tried to do .285714(x/.0525-x) but this doesn't worl. The answer is 1.2g.

asked by Nancy on January 4, 2014
44. ## chem

the pH of a .100 M solution of sodium formate = 8.37. Calculate the value of Ka of formic acid. okay so I know that the anion of a weak acid is itself a weak base so A- +H2O---> OH- + HA pOH =14-8.37 so conc of OH is 10^-5.63 Ka=[OH][HA]/[A-] so we know

asked by Natash on May 13, 2009
45. ## Chemistry

In the neutralization of HCl and NaOH i was instructed to measure the temperature of the acid HCl prior to mixing the reaction components. I was to assume however, that the NaOH solution was at this same temperature. Is this a reasonable assumption?

asked by Jane on April 7, 2010
46. ## Chemistry

Hello, please I need help with this excersice of chemical equilibrum. I really don't get what "1:6" means and how can I use that proportion". The excercise says: "0,014" moles of HCl are dissolved in water in a proportion of 1:6 (1 mole of HCl per 6 moles

asked by Nelson on August 27, 2016
47. ## Chemistry

7 grams of chloride was dissolved in water. 20 ml of lead(II)nitrate was used to completely precipitate all chloride (assume atomic mass of 35g/mol). What is the molarity of the Lead(II) Nitrate solution.

asked by Luke on November 12, 2012
48. ## chemistry

what mass of silver chloride can be prepared by the reaction of 100 ml 0,20 M of silver nitrate with 100,0 ml of 0.15 M calcium chloride calculate the concentration of each ion reamaining in solution after the precipitation is complete

asked by mathew on September 24, 2014
49. ## chem - freezing point

When 18 g of ethylene glycol C2H6O2 is dissolved in 150 g of pure water, the freezing point of the solution is _____ C. (The freezing point depression constant for water is 186C kgmol.

asked by jerry on October 4, 2010
50. ## Chemistry

7 grams of chloride was dissolved in water. 20 ml of lead(II)nitrate was used to completely precipitate all chloride (assume atomic mass of 35g/mol). What is the molarity of the Lead(II) Nitrate solution.

asked by Luke on November 12, 2012
51. ## ap chem

Bismuth can be electrolytically reduced according to the following reaction: BiO(+)+ 2H(+)+ 3e¯ >>> Bi + H2O How many grams of bismuth can be reduced by applying a 5.60 A current for 23.8 min. to a solution containing BiO+ ions (assuming 100% efficiency)?

asked by Anonymous on May 22, 2015
52. ## chemistry

Benzene is a carcinogenic (cancer-causing) compound. A benzene-contaminated water sample contains 3.1×10−5% benzene by mass. What volume of the water in liters contains 225mg of benzene? (Assume that the density of the solution is 1.0 g/mL.)

asked by Anon on November 19, 2014
53. ## organic chemistry

should you use decolorizing charcoal before allowing the hot solution to cool in? Explain Your answer is here. http://www.google.com/search?hl=en&lr=&ie=ISO-8859-1&q=decolorizing+charcoal&btnG=Search

asked by sheri on November 12, 2006
54. ## Chemistry

How would I calculate the heat of solution in Joules for dissolving 0.1 mole of NH4NO3 in 100 mL of water? The initial temperature was 22.8 degrees celsius and the temperature after the salt dissolved was 18.1 degrees celsius.

asked by Zach on July 24, 2012
55. ## Math

A jeepney ride costs 8 pesos for the first 4 km and each additional integer km add 1.50 pesos to the fare. Use a piecewise function to represent the jeepney fare in terms of the distance (d) in km. Please give the solution. Thank you

asked by Kyle David desoyo on June 19, 2017
56. ## math

find the next number in the following sequence; 1/2,2/3,3/5,5/8, _ *please i need your assistance guys for this question* My idea is as follows denominator part for the given fraction =1+2 =3 then 2+3 =5, 3+5=8,therefore the next denominator part = 5+8 =13

asked by kelvin on July 2, 2017
57. ## physical chemistry

Estimate the boiling point of 250 cm3 of water to which 12.6 g of phenol(C6H5OH) has been added. Treat the solution as ideal.( water of boiling point elevation is 0.51K/mol)

asked by Byeong Ju on April 23, 2017
58. ## math

A cow is tied with a rope of length 14 m at the corner of rectangular field measured 20 m by 16 m. Find the area of the field in which the cow can graze. #anyone to help me with proper and systematic step by step solution

asked by kelvin on April 19, 2017
59. ## chemistry

Consider an acid, HA, with pKa =3.33 0.025 moles of hydroxide ion are added to 17.4mL of a 0.519 M solution of the acid. What is the resulting pH? I know pKa=-log([Ka]) pH=-log([H+]) I don't know how to link this information. Thanks

asked by Sarah on February 28, 2008
60. ## Language Arts

Which of the following statements about a short story plot is not true? (1 point) The plot has a beginning, middle, and end. The plot is when and where the story takes place. The plot usually starts with a problem and ends with a solution.

asked by Camryn on November 13, 2012
61. ## Science

1.0 g of copper was heated in a crucible, while stirring, and .2g of unreacted copper was recovered usoing hydrochloric acid as a solvent, how much copper would precipitate when zinc is later added to the copper oxide/acid solution?

asked by R Johnson on March 13, 2013
62. ## Chemistry

Mercury(II) sulfide, HgS, is practically insoluble in pure water. Its solubility at 25 degrees C is probably no more than 3×10^−25 g/L. Of the following quantities of pure water, which is the smallest quantity that could be used to make a saturated

asked by Helena on May 2, 2016
63. ## Chemistry

A viral contains radioactive iodine -131 with an activity of 2.0 mCi per milliliter. If the thyroid test requires 3.0 mCi in an "atomic cocktail", how many milliliters are used to prepare the iodine -131 solution ?

asked by Anonymous on July 20, 2010
64. ## chemistry

How much heat is required to raise the temperature of 200 g CH3OH from 20 to 30 degrees and then vaporize it at 30 degrees. The molar heat capacity of CH3OH is 81.1 J/Mol/K. Okay...the answer is approximately around 254. It was a homework problem. The

asked by joseph on February 13, 2010
65. ## mathematics

Please help me answer this question; 1.A metal gutter open at the tops and ends, is bent up from material 30 cm wide to form a rectangular cross section. a) If the base of the gutter is x cm wide, find the height of the gutter. b)Show that the area of the

asked by Ruby on August 29, 2011
66. ## Science NEED HELP NOW

Bill and Amy want to ride their bikes from their neighborhood to school which is 14.4 kilometers away. It takes Amy 40 minutes to arrive at school. Bill arrives 20 minutes after Amy. How much faster (in meters/second) is Amy’s average speed for the

asked by Marias on October 2, 2011
67. ## chemistry

How much heat is required to raise the temperature of 200 g CH3OH from 20 to 30 degrees and then vaporize it at 30 degrees. The molar heat capacity of CH3OH is 81.1 J/Mol/K. Okay...the answer is approximately around 254. It was a homework problem. The

asked by joseph on February 13, 2010
68. ## math

a species of orchid is being studied. The population 'p' at time 't' years after the study started is assumed to be p = 2800ae^0.2t/1 + ae^0.2t where 'a' is a constant. Given tnat there were 300 orchids when the study started. a. show that a =0.12 b. use

asked by lindsay on March 18, 2013
69. ## Chemistry

1) 800 mL of 0.025 M Pb(NO3)2 is mixed with 500 mL of 0.030 M K2CrO4. Calculate the grams of PbCrO4 that form. I am confused on how to do this I got the answer it should be 4.85 g PbCrO4, but I would want to know how to get that. And also Limiting reactant

asked by Akbar on April 4, 2012
70. ## Science

Bill and Amy want to ride their bikes from their neighborhood to school which is 14.4 kilometers away. It takes Amy 40 minutes to arrive at school. Bill arrives 20 minutes after Amy. How much faster (in meters/second) is Amy’s average speed for the

asked by Marias on October 2, 2011
71. ## physics

A horse pulls upon a wagon, but according to Newton’s third law the wagon pulls back with an equal and opposite force upon the horse. Use a free-body diagram and show all the involved forces. i posted this question before but i still don't get it. Could

asked by Alex on July 17, 2012
72. ## math help please

Which of the following types of information is suited for display on a scatter plot? A. Relationship between favorite color and age. B. Relationship between number of pets and favorite TV show C. Relationship between hours of exercise and number of

asked by Anonymous on March 19, 2015
73. ## chemistry Equations

Write euations to show how a buffer made up of equimolar amounts of acetic acid, CH3COOH, and acetate, CH3COO-, would behave when (a) HCl was added and (b) NaOH was added. Is this right,If not what is the correct way? CH3COOH + HCl ----> CH3COOHCl + OH

asked by Lan on April 20, 2014
74. ## chemistry

The density of diamond is 3.51 g/cm^3 and the density of platinum is 21.43g/cm^3. If equal masses of diamond and platinum are transferred to equal volumes of water in separate graduated cylinders, which graduated cylinder would have the greatest volume

asked by summer on January 22, 2017
75. ## math 115

What units in the metric system would you use to measure each of the following quantities?= The United States emitted 19.5 million t of nitrogen oxides (NO) into the atmosphere in 1987. One metric ton (1 t) equals 1,000 kg. How many kilograms of NO were

asked by amber on September 30, 2009
76. ## math 115

What units in the metric system would you use to measure each of the following quantities?= The United States emitted 19.5 million t of nitrogen oxides (NO) into the atmosphere in 1987. One metric ton (1 t) equals 1,000 kg. How many kilograms of NO were

asked by amber on September 30, 2009
77. ## Government

1: how does someone become a member of the supreme court?(1 point) > by popular election and senate approval*** >by judicial appointment and presidential approval >by presidential appointment and senate approval >by senatorial appointment and judicial

asked by HELP on September 20, 2016
78. ## solid mensuration

Find the area of a portion of a semicircle of radius 15 m that is outside the area of an inscribed square if the base of the square lies on the diameter of the semicircle. Please include solution. Thanks.

asked by Cathy on December 1, 2012
79. ## chemistry

A solution that contains 55.0 g of ascorbic acid (Vitamin C) in 250. g of water freezes at −2.34°C. Calculate the molar mass (in units of g/mol) of the ascorbic acid. Kf of water is 1.86°C/m.

asked by Diana on September 8, 2010
80. ## Chemistry

Concentrated hydrochloric acid is 12 M. What is the molarity of an HCl solution prepared by diluting 10.0mL of concentrated acid to a total volume of 250.0mL?

asked by Sam on March 8, 2016
81. ## Mat/116

what is the solution set {c/c

asked by Denise on May 27, 2010
82. ## chemistry

What mass in grams of an aqueous hydrochloric acid solution that is 37.0% by mass hydrogen chloride is needed to supply 2.000 moles of hydrogen chloride?

asked by Li on October 4, 2011
83. ## Chemistry

Calculate the concentration of IO3– in a 9.23 mM Pb(NO3)2 solution saturated with Pb(IO3)2. The Ksp of Pb(IO3)2 is 2.5 × 10-13. Assume that Pb(IO3)2 is a negligible source of Pb2 compared to Pb(NO3)2.

asked by Sonya on February 20, 2014
84. ## chem

A sample of hexane was cracked. A sample of 50cm³ of gas was produced. The gas decolorized 4cm³ of 0.23moldm–³ solution of bromine. What % of alkenes was produced?

asked by jay on April 13, 2016
85. ## Solid Mensuration

Two similar cones have volumes 81pi/2 in^3 and 12pi in^3 and slant height of the bigger cone is 7.5 in. Find the integer solution to the height of the similar cone.

asked by Paul on March 2, 2012
86. ## 5th grade math

each letter represents a different digit from 1 to 9. what number TWO represents? ONE + ONE --------------- TWO i found two solution so far but only by trial and error, can someone tell me if there is more and what they are? 134 +134 ------ 268 356 +356

asked by edina on September 16, 2016
87. ## chem

Calculate the concentration of IO3– in a 4.73 mM Pb(NO3)2 solution saturated with Pb(IO3)2. The Ksp of Pb(IO3)2 is 2.5 × 10-13. Assume that Pb(IO3)2 is a negligible source of Pb2 compared to Pb(NO3)2.

asked by khadra on October 13, 2014
88. ## Solid Mensuration

Two similar cones have volumes 81pi/2 in^3 and 12pi in^3 and slant height of the bigger cone is 7.5 in. Find the integer solution to the height of the similar cone.

asked by Paul on March 2, 2012
89. ## chemistry

when a zinc strip is placed in a copper nitrate solution, the strip becomes coated with copper. write down the oxidation half-reaction for the reaction that takes place.

asked by Anonymous on July 27, 2010
90. ## chem

A sample of hexane was cracked. A sample of 50cm³ of gas was produced. The gas decolorized 4cm³ of 0.23moldm–³ solution of bromine. What % of aliens was produced?

asked by jay on April 13, 2016
91. ## Chemistry

You have a 135 mL buffer solution of 0.35 M NH3 and 0.40 M NH4+ in concentration. NH4+ (aq) + H2O (l) H3O+ (aq) +NH3 (aq) Calculate the pH of this buffer after adding 10.00 mL of 0.095 M NaOH.

asked by TP on April 3, 2018
92. ## chemistry

10.0mL of solution containing 20.0 mL of 1.0 M NaX (unknown base) and 10.0 mL of 1.0 M HX (unknown acid) was diluted with 50.0 ml water. The pH is 4.92. What is the concentration of HX after dilution and X- after dilution? What is the equilibrium

asked by kelly on February 27, 2010
93. ## Chemistry

I need help with this question, I don't know how to do it. If 210 mL of isopropyl alcohol is diluted with water to a total volume of 300 mL, what is the percent by volume of isopropyl alcohol in the solution?

asked by rebekah on April 3, 2016
94. ## Help!!!!!!!!!!!!

A 0.391 g sample of KHP will be titrated with a NaOH solution with an assumed concentration of 0.100 M. Calculate the volume of NaOH that should neutralize the KHP sample.

asked by Jackie on March 3, 2014
95. ## chemistry

silver sulphate is a sparingly soluble salt.2.5litres of saturated solution of this salt contains 14.25g. Calculate the molar solubility of silver sulphate

asked by victor1 on April 6, 2012
96. ## Chemistry

If 20ml of glacial acetic acid (pure HC2H3O2) is diluted to 1.5L with water, what is the pH of the resulting solution. The density of glacial acetic acid is 1.08g/ml

asked by Kristen on August 2, 2010
97. ## chemistry 105

Consider the following reaction: Li2S(aq)+Co(NO3)2(aq)-->2LiNO3(aq)+CoS(s) What volume of 0.150 M Li2S solution is required to completely react with 125 mL of 0.150 M Co(NO3)2?

asked by julie on October 10, 2011
98. ## Chemistery

consider the reaction N2O5 + h2o -> 2HNO3 how many moles of N2O5 must be dissolved into one more of H2O to obtain an aqueous solution of HNO3 in which the mole fraction of HNO3 is 0.5

asked by PInk ROSEE on December 11, 2015
99. ## physics

Compute the order of magnitude of the mass of (a) a bathtub filled with water, and (b) a bathtub filled with pennies. In your solution list the quantities you estimate and the value you estimate for each.

asked by aaron on September 20, 2010
100. ## physics

A test charge of +2 x 10^-7 C is located 5 cm to the right of a charge of +1 x 10^-6 C and 10 cm to the left of a charge of -1x10^-6 C. The three charges lie on a straight line. Find the force on the test charge? with solution

asked by jesmaincruz on November 13, 2012