# why does the equation x^2=-9 has no real solution why does the equation x^2 = 9 has two solutions

56,329 questions, page 169
1. ## Physics

A biotech company produces a solution with an active biomass of 8.7604x10^6 cells per litre of solution. The solution is shipped by tanker truck with a volume of 4.16462x10^1 m3. How many cells are being sent per shipment, expressed to three significant

asked by stacy on October 3, 2010
2. ## Chemistry

Question: A 0.400 g sample of propionic acid was dissolved in water to give 50.00 mL of solution. This solution was titrated with 0.150 M NaOH. what was the pH of the solution when the equivalence point was reached? I'm not really sure how i would go about

asked by Eliz on April 15, 2009
3. ## Chemistry

A chemist has 250.0 mL of a bright blue (caused by Cu+2) aqueous solution that contains 21.16 g of CuCl2. He adds 12.0 g of finely ground silver to the blue solution and lets the solution sit covered overnight. When he returns he finds:

asked by Anonymous on October 10, 2011
4. ## chemistry

Assume that 50ml of 0.01M edta solution were added to 25ml of co solution and the excess edta required 20ml of 0.005M mg solution. Calculate ppm co+ present. The answer 942ppm Bob helps me

asked by Fai on March 2, 2013
5. ## Chemistry

What mass of solid sodium acetate, NaCH3COO, must be added to 2.50 L of an aqueous solution of 0.55 M acetic acid, CH3COOH, in order to make a buffer solution whose pH is 4.50? Assume that adding the solid does not change the volume of the solution.

asked by Dee on December 15, 2012

A solution of 220mL of 0.200M Koh is mixed with a solution of 120mL of 0.240M NiSO4. 1.Determine limiting reactant? 2.Calculate the mass of precipitate formed? 3.Calculate the molarity of all ions left in the solution?

asked by anonymous on October 9, 2011
7. ## chemistry

calculate final volume required to reach 1% solution when 0.2g of sample is predigested with nitric acid 3mL then after 1day, if 1ml sample from this solution is digested in 10ml solution and diluted in 50 mL distilled water.

asked by tomas on March 20, 2011
8. ## chemistry

A solution of 220mL of 0.200M Koh is mixed with a solution of 120mL of 0.240M NiSO4. 1.Determine limiting reactant? 2.Calculate the mass of precipitate formed? 3.Calculate the molarity of all ions left in the solution?

asked by anonymous on October 9, 2011
9. ## Chemistry

A solution of 220mL of 0.200M Koh is mixed with a solution of 120mL of 0.240M NiSO4. 1.Determine limiting reactant? 2.Calculate the mass of precipitate formed? 3.Calculate the molarity of all ions left in the solution?

asked by anonymous on October 9, 2011
10. ## Chemistry

You weigh out 196.07mg ferrous ammounium sulfate (FW 392.14) to prepare 250mL of solution which is 0.002M with respect to that compound. The salt is quantitatively transferred into a 250mL volumetric flask and 8mL of 3M H2SO4 is added and then diluted to

asked by Ken on December 7, 2011
11. ## Physics

A train travels between stations 1 and 2. The engineer of the train is instructed to start from rest at station 1 and accelerate uniformly between points A and B, then coast with a uniform velocity between points B and C, and finally accelerate uniformly

12. ## chemistry

What is th pH of a buffer solution made by dissolving 0.10 mol of formic acid, HCOOH, and 0.10 mol of sodium formate, HCOONa, in 1L of water? What is the molarity of a solution made by dissolving 3.4g of Ba(OH)2 in enough water to make 450mL of solution?

asked by Taylor on November 18, 2009
13. ## chemistry

hello this is ellie again. I need help on this one problem A solution of 0.314M KOH is used to neutralize 10.0mL H3PO4 solution. H3PO4(aq) + 3KOH(aq) โ K3PO4(aq) + 3H2O(l) If 29.3mL KOH solution is required to reach the endpoint, what is the molarity of

asked by ellie on December 3, 2013
14. ## Algebra

A chemist mixed a 70% alcohol solution with a 30% alcohol solution to make a 45% alcohol solution. How many liters of each were used to make 120 L of a 45% solution? I tried solving this with elimination method and made two separate equations. For

asked by Annie on May 20, 2016
15. ## chem

what is a liquid solution and a gaseous solution? [define plz] liquid solution: sea water gas solution: air i don't need examples. i need definitions. they are not in my book. a liquid solution is a mixture of atoms/ions/chemicals, etc. dissolved in water.

asked by revie on May 15, 2007
16. ## College Chemistry Lab

Suppose that a 2.50x10^-6M solution of red dye No. 2 had an absorbance of 0.585 at its wavelength of maximum absorbance. A second solution of red dye No. 2 is too concentrated to read its absorbance so 5.00 mL of the concentrated dye solution was diluted

asked by L** on March 16, 2010
17. ## space

What is the force of gravity at 220 miles above Earth's surface? Calculate how much of a g force the astronauts are actually experiencing. The solution for this math problem is a percentage. You can calculate it using the Algebraic equation: gr = R2/r2 x g

asked by Annie on January 21, 2010
18. ## CHEMISTRY

Equilibrium Equation with Partial Pressures PCl3(g) +Cl2(g) PCl5(g)? An equilibrium mixture of PCl5(g), PCl3(g), and Cl2(g) has partial pressures of 217.0 Torr, 13.2 Torr, and 13.2 Torr, respectively. A quantity of Cl2(g) is injected into the mixture, and

asked by Kylie on March 9, 2012
19. ## Chemistry

2. You have a sugar solution (solution A) with concentration x. You pour one-fourth of this solution into a beaker, and add an equivalent volume of water (solution B). a) What is the ratio of sugar in solutions A and B? b) Compare the volumes of soutions A

asked by Jon on January 13, 2007
20. ## chemistry

Hey, can somebody here help me with this stuff? 1) Why are radioisotopes with long half-lives not administered internally in medical procedures? 2) What % of C-14 would you expect a piece of 34000 year-old fossilized bone from a mastodon to have when

asked by Roger on January 2, 2007
21. ## math

You have just received advertisements from 2 companies in your area: Greener Lawns and Lawns for Less. Greener Lawns charges an initial fee of \$200, plus \$50 per hour for labor costs. Lawns for Less charge an initial fee of \$300, plus \$25 per hour for

asked by tammy on March 13, 2011
22. ## "le Chat. principle".

Hey, can you check this, this is regarding "le Chat. principle". Thanks! #1) The value of the equilibrium constant for the reaction H2CO3(aq) + energy >>> H2O(l) + CO2(g) can be changed by introducing a change to which component of the equation? My answer:

asked by Dave on July 19, 2006
23. ## Chemistry!!

A chemist wants to prepare a stock solution of H2SO4 so that a sample of 20.00mL will produce a solution with a concentration of .50 M when added to 100.0mL of water. A)what should the molarity of the stock solution be? B)If the chemist wants to prepare

asked by Anonymous on April 22, 2013
24. ## Chem 1

Use the following data (in kJ/mol) to estimate the standard enthalpy of formation (in kJ/mol) for hypothetical compound CsF2 in the solid state. Lattice energy of CsF2 -2347 First ionization energy of Cs 375.7 Second ionization energy of Cs 2422 Electron

asked by Rossina on November 1, 2006
25. ## Calculus (Limits)

If g(x) is continuous for all real numbers and g(3) = -1, g(4) = 2, which of the following are necessarily true? I. g(x) = 1 at least once II. lim g(x) = g(3.5) as x aproaches 3.5. III. lim g(x) as x approaches 3 from the left = lim g(x) as x approaches

asked by Mishaka on October 22, 2011
26. ## Calculus

If g(x) is continuous for all real numbers and g(3) = -1, g(4) = 2, which of the following are necessarily true? I. g(x) = 1 at least once II. lim g(x) = g(3.5) as x aproaches 3.5. III. lim g(x) as x approaches 3 from the left = lim g(x) as x approaches

asked by Mishaka on October 22, 2011
27. ## Math

1. Which of these numbers can be classified as both real and irrational? 5.858585858 63.4 square root 21 ** square root 36 2. Which is both a real number and an integer? 23 ** 1 over 4 square root 27 3.402538 3. Which of these numbers is classified as both

asked by Cassidy on October 17, 2016
28. ## economics

At an initial point on the aggregate demand curve, the price level is 100, and real to GDP is \$15trillion. After the price level rises to 110, however, there is an upward movement along the aggregate demand curve, and real GDP declines to \$14 trillion. If

asked by Tina on July 9, 2011
29. ## math

According to the center of Science in the Public Interest, the maximum healthy weight for a person who is 5 feet, 5 inches is 150 pounds and the maximum healthy weight for a person 6 feet, 3 inches tall is 200 pounds. The relationship between weight and

asked by guitarman on March 29, 2010
30. ## AP Chem

A student chemist named Hannah Montana set up an electrical conductivity tester similar to that shown on page 141 and conducted an experiment involving two clear, colorless liquids, identified as solution A and solution B. Solution A and Solution B are

asked by dylan on October 11, 2010
31. ## algebra

geometric dot pattern. 1+2+...+80 I'm not sure what the question is, to add up the numbers from 1 to 80? If it is this is an extremely old problem. If you use the progression o 1 dot____ ..o ..oo 3 dots___ .....o .....oo .....ooo .....oooo 4dots____ the

asked by jaznai on September 12, 2006
32. ## Algebra II

What is the domain of y = 2/(x) + 2 x>0 x=0 All real numbers except x = 0 I think the domain is All real numbers except x = 0 Is that correct?

asked by Matt- on November 1, 2010
33. ## Algebra

What is the domain of y = 2/(x) + 2 x>0 x=0 All real numbers except x = 0 I think the domain is All real numbers except x = 0 Is that correct?

asked by Matt- on November 2, 2010
34. ## Algebra

Please check this. f(x)= 1/(x-1)^2 - 5 D= all real numbers, x does not equal to -5 R= all real numbers, y does not equal to 1

asked by Anonymous on August 17, 2015
35. ## physics

A stone is thrown vertically upward. On its way up it passes point A with speed, v and point B, 3 m higher than A, with speed 1/2v. Calculate a) the speed v and b) the max height reached by the stone above point B. I can't find the equation You need to

asked by jenny on September 17, 2006
36. ## Algerbra

A homeowner wanted to improve the value of his home by putting tile flooring in three of his rooms. He researched the different types of tile and decided on two types: ceramic tile and decorative tile. He found that he could purchase the ceramic tile for

asked by Anonymous on August 10, 2010
37. ## Physics

Under what conditions can a quadratic function be a perfect square? Also.. A stone is thrown vertically upward at a speed of 40m/s. How long does it take to reach a height of 90m? I ended up with a quadratic of t^2-8t+18 which cannot be factored...So is

asked by Anonymous on February 19, 2008
38. ## Physics

Under what conditions can a quadratic function be a perfect square? Also.. A stone is thrown vertically upward at a speed of 40m/s. How long does it take to reach a height of 90m? I ended up with a quadratic of t^2-8t+18 which cannot be factored...So is

asked by Anonymous on February 19, 2008
39. ## BLD 414

A liquid solution of formaldehyde is 37.0% pure. This solution has a specific gravity of 1.037. The molecular weight of formaldehyde is 30.0. to 1.00 ml of this impure stock solution is added quantity sufficient to take the total volume to 500ml. If 1.00

asked by Amber` on March 19, 2012
40. ## Chem Lab Math!

A liquid solution of formaldehyde is 37.0% pure. This solution has a specific gravity of 1.037. The molecular weight of formaldehyde is 30.0. to 1.00 ml of this impure stock solution is added quantity sufficient to take the total volume to 500ml. If 1.00

asked by Morgan M on March 18, 2012
41. ## chemistry

0.5 L of a 0.30 M HCl solution is titrated with a solution of 0.6 M KOH. a)What is the pH before addition of KOH? b)What is the total number of moles of acid? c)What is the pH after addition of 125 mL of KOH solution? d)What volume of the KOH solution is

asked by Joe on April 28, 2011
42. ## math

A rental car company charges a fixed fee of \$15.00 plus \$.12 per mile. Write an equation to find the total cost, y, for any number of miles, x

asked by jara on March 31, 2019
43. ## chem

if 2.19e-9 mol of 176-W emits 1.07e15 beta particles in 1 hour. what is the decay constant? how do i go about doing this? i know the equation 0.693=kt(1/2) but i don't think that is helpful here

asked by sara on September 16, 2014
44. ## Maths

1. Show that k=15 is congruent integer. where 0.5xy=km^2, x=r(u^2 - v^2) y=r(2uv) z=r(u^2 + v^2) x^2 + y^2 = z^2 2. how i solve Pell's equation using bhaskara II then brahmagupta method for x^2 - 67y^2 =1 Please help, exam on monday... :)

asked by Elven on May 6, 2017
45. ## Chemistry

Assume that 7.2 L of I2 are produced at STP according to the following balanced equation: 2KI+Cl - 2KCl+ I2 How many grams of KI (MOLAR MASS=166.002G/MOL) reacted

asked by Valerie on January 15, 2013
46. ## math

a car rental company charges a flat rate of \$29 per day and an additional \$0.15 per mile. Write an equation to model the total charge

asked by hannah on December 10, 2013
47. ## chemistry

Consider the equation A(aq) + 2B(aq) 3C(aq) + 2D(aq). In one experiment, 45.0 mL of 0.050 M A is mixed with 25.0 mL 0.100 M B. At equilibrium the concentration of C is 0.0410 M. Calculate K. a) 7.3 b) 0.34 c) 0.040 d) 0.14 e) none of these the answer for

asked by raf on April 4, 2011
48. ## Chemistry

I have 3 Fe (s) + 4 (H2O) (g) reacts with FeO4 (s) + 4 H2 (g) How many g of steam and iron must react to produce 375 g of magnetic oxide Fe3O4 ? I need help trying to figure out how to write the equation please

asked by June on October 27, 2014
49. ## math

Find the coefficient of determination and the standard error estimate for the regression equation fitting each of the following data sets.interpret the result in each case x:-3,-2,-1,0,1,2,3 y:-1,0,1,2,5,6,8

asked by naa on September 15, 2016
50. ## chemistry

Assume that 7.2 L of I2 are produced at STP according to the following balanced equation: 2KI+Cl - 2KCl+ I2 How many grams of KI (MOLAR MASS=166.002G/MOL) reacted

asked by Valerie i need it ASAP on January 15, 2013
51. ## Pre-Calculus

Find the equation of the ellipse whose semi-major axis has length 6 and whose foci are at (3,-2+/-sqrt11). I have the focal constant = 2a which means that a=3 but don't know how to proceed. Thanks.

asked by Lucy on October 12, 2008
52. ## math

a technician charges \$75.00 for consult plus \$35.00 per hour. write an equation for the function. what are the variables represent and find the number of hours if he charged you \$285.

asked by shelly on November 5, 2017
53. ## chemistry

How to balanced chemical equation and identify the type of reaction for solid ammonium nitrate decomposes into dinitrogen monoxide gas and water

asked by judy on February 1, 2017
54. ## chemistry

when propane gas C3H8, is burned with oxygen, the products are carbon dioxide and water. Write an unbalanced formula equation for the reaction.

asked by kate on February 3, 2009
55. ## calculus

find the positive roots of the equation 2x^3-5x^2+6=0 and evaluate the function y=500x^6 at each root. round you answers to the nearest integer, but only in the final step.

asked by maritza on November 22, 2010
56. ## Chemistry

Write a balanced chemical equation that represents the self-ionization of water. (Use the lowest possible coefficients. Include states-of-matter at 1 atm and 25ยฐC in your answer.)

asked by Grace on April 2, 2014
57. ## Physics

A particle moves according to the equation x(t) = (10 m/s2) t2 where x is in meters and t is in seconds. Find the average velocity for the time interval from t1 = 2.0 s to t2 = 3 s. Answer in units of m/s. Please help! I have no idea how to set this up :(

asked by Christie on September 7, 2014
58. ## Chemistry

I am having trouble in calculating equilibrium concentrations. Where I get stuck will be at the end where I have to square root both sides and get the value of x to plug in the equation to get the individual concentration of every substance.

asked by Rosa on March 18, 2008
59. ## Trig

2cos^2Beta-Cosbeta=0 (find all solutions for the equation in the interval 0, 2 pi). I have no idea how to go about doing this. Do you isolate the beta on one side? Would you be able to show me how and I'll solve for you to check?

asked by Janie on January 24, 2010
60. ## Calculus

Hi, I'm absolutely stuck on this problem. This is for a newton's method/linearization unit. Find an equation for the curve in the xy-plane that passes through the point (1,-1) if its slope at x is always 3x^2+2.

asked by Jay on January 1, 2011
61. ## maths help needed!

Hi, just a short question. How do i find the x intercepts for the equation y=-2x^3+1 ? I tried to let y equal zero but i could only get as far as x^3=1/2 please help! x^3 = 1/2 is correct. There is only ine x-intercept. It is where x = (1/2)^(1/3) which

asked by elle on March 5, 2007
62. ## chemestry

I need serious help on this....please help guys.. i've to turn it in in an hours... Balance th following equation in acid Solutiong and determind if it is spontaneous under standard conditions. NO3^-1 + Sn^+2 ---> NO + Sn^+4 Please do not post duplicates.

asked by bik on May 16, 2007
63. ## AP Calc-easy ?

Given: f(x)= x^3 + x^2 - 2x over the closed interval [0,2] Write the equation of the tangent line to f(x) passing through point A(-1,-2). *At first glance I knew how to do it, but f(-1) does not equal -2...so do I add a constant onto f(x) to make f(-1) =

asked by blondie07 on March 7, 2007
64. ## Algebra

Solve each system graphically. #6. 4x - y = 9 x - 3y = 16 I need to find at least one pair of points that fit. I tried using the elimination method and got (5 and 6/7, -22), which did not even work for the first equation. I also tried graphing it but it

asked by Suzanne on February 18, 2009
65. ## CHEMISTRY

What volume of H2 would be obtained at 27 degrees Celsius and 1.0 atm if 35.0 g of Fe reacts with 0.75 mil of H2SO4? Equation: 2Fe + 3H2SO4 = 3H2 + Fe2(SO4)3

asked by bm24 on August 23, 2018
66. ## Chemistry

Write a balanced chemical equation and determine the enthalpy of combustion for carbon in the diamond allotropic form. Is this the correct chemuc eq? C + O2 ----> CO2?

asked by Lana on January 14, 2016
67. ## Algebra

You borrow \$40 from your sister. To repay the loan, you pay her \$5 a week. Write a linear equation to model the situation and check with unit alalysis.

asked by Qwerty on November 13, 2011
68. ## Chemistry

Calculate ฮG (in kJ) at 298 K for some solid ZnF2, 0.055 M Zn2+ and 0.063 M F-(aq). I found Q to be 2.18e-4, then i implemented it into the equation deltaG=RT(lnQ). I got -20.89, but the answer is -12.2.

asked by JUNDY on April 7, 2015
69. ## algebra

solve the system by the method of substitution x-4y=-21 3x+y=2 I got (0,2) Try plugging in x=0 and y=2 into your first equiation and uopu will that your answer must be wrong. Do it this way: x - 4y =-21 12x+ 4y =8 13 x = -13 x = -1 y = 2 - 3x = ? x=0 and

asked by Rose on December 14, 2006
70. ## Beginning Algebra

how do i figure out this problem i have to make the equation true by inserting one or more parenthesis a. 2 * 3^2 + 4 * 3 - 1 = 47 For this a. 2 * 3^2 + 4 * 3 - 1 = 47 You need a fairly large number compared with the available numbers, so you might try

asked by Eliana on September 27, 2006
71. ## chemistry

3. Complete the following word equation and write the balanced formula equations: a. Zinc(s) + iodine(g) b. Hydrogen peroxide(l) c. Magnesium(s) + lead(IV) nitrate(aq)

asked by Anonymous on March 4, 2012
72. ## Microeconomics

Consider a single price monopoly that faces a market demand curve for a good is given by the equation ๐=100โ.1๐ and the total cost function is given as ๐๐ถ=1000+20๐+.4๐2.

asked by Ella on September 12, 2016
73. ## General Mathematics

The value of your property is rising by 100,000 per year. If it is worth 1.5 million today what will it be in 10 years? Finding the equation of the problem using exponential form.

asked by Anonymous on July 18, 2018
74. ## anayltical chemistry

I have tried and tried to use the henderson-hasselbalch equation for this problem, but i do not understand how to plug in the data: how much ammonium sulfate should be added to 500mL of .3M ammonia to produce a buffer with a pH of 9.?

asked by joey on November 22, 2010
75. ## Chemistry

Assume that 7.2 L of I2 are produced at STP according to the following balanced equation: 2KI+Cl - 2KCl+ I2 How many grams of KI (MOLAR MASS=166.002G/MOL) reacted

asked by Valerie on January 15, 2013
76. ## algebra

How to put this math problem in power point presentation. Evaluate both expressions by using R= 120 and s = 200 : Find the LCD of the terms in the equation.

asked by faith on August 20, 2011
77. ## College Chem

Based on the balanced equation 4Na + O2 โ 2Na2O calculate the number of Na2O formula units formed when 60 Na atoms and 10 O2 molecules react? Thanks.

asked by Lance on April 15, 2012
78. ## College Chem

Based on the balanced equation 4Na + O2 โ 2Na2O calculate the number of Na2O formula units formed when 60 Na atoms and 10 O2 molecules react? Thanks.

asked by Lance on April 15, 2012
79. ## Reposting Chemistry College

Based on the balanced equation 4Na + O2 โ 2Na2O calculate the number of Na2O formula units formed when 60 Na atoms and 10 O2 molecules react? Thanks.

asked by Lance on April 15, 2012
80. ## Math

A piano tuner uses a tuning fork. If middle C has a frequency of 264 vibrations per second, write an equation in the form for the simple harmonic motion.

asked by Lisa on October 9, 2006
81. ## chemistry

Using the balanced equation, determine the number of NaNO3 units in the visualization in the reaction. 3Ca(NO3)2(aq) + 2Na3PO4(aq) โ 6NaNO3(aq) + Ca3(PO4)2(s)

asked by eng on January 20, 2010
82. ## Chemistry

Assume that 7.2 L of I2 are produced at STP according to the following balanced equation: 2KI+Cl - 2KCl+ I2 How many grams of KI (MOLAR MASS=166.002G/MOL) reacted

asked by Valerie on January 15, 2013
83. ## Chemistry

Write a net ionic equation for the overall reaction that occurs when aqueous solutions of potassium hydroxide and oxalic acid (H2C2O4) are combined.

asked by Adriana on September 28, 2016
84. ## Chemistry

Why was the tert butyl chloride washed with aqueous sodium hydrogen carbonate? what gas was evolved during the washing? Write a balance equation

asked by Issac on September 30, 2017
85. ## Math

Approximate the equation's solutions in the interval (0,2pi). sin2x sinx = cosx I know that I should work on the left side first. I know how to solve for the intervals but I am just not sure how to start this off.

asked by Hannah on March 1, 2010
86. ## Algebra

If the trend for the growth in the median home value continues=d, what would be its value in the year 2007? show how you obtained your answer using the linear equation you found in part c).

asked by Jewel on June 7, 2012
87. ## Chem

The value of ฦยขHยโน for the reaction below is -482 kJ. Calculate the heat (kJ) released to the surroundings when 12.0 g of CO(g) reacts completely. 2CO(g) + O2(g) ยยจ 2CO2(g) *I just want to how to solve this problem as in an equation, not the answer.

asked by Harlem on June 8, 2012
88. ## college chemistry

At 625 K the value of Kc for the equilibrium represented by the balanced equation is 2.50 x 100. Calculate the value of Kp at the same temperature. Express answer in scientific notation. 2NH3(g) = N2(g)+3H2(g)

asked by sparkle on October 4, 2010
89. ## Algebra

okay- i definetly don't remember how to do this: Give an ordered pair(a,b)of numbers that satisfy the equation: 6a+b=8 Common sense says that a = 1 (6 x 1 = 6) b = 2 6 + 2 = 8 omigosh.. im dumb.. lol - ok thanks!

asked by Briana on January 21, 2007
90. ## algebra

1) a line has a slope of 5. it passes through the points (1,4) and (6,y). what is the value of y? explain how you found your answer. 2) write a direct variation equation that relates x miles to y kilometers.

asked by hailey on May 19, 2015
91. ## AP physics

According to the equation a=bc what type of relationship (direct or inverse) exerts between the quantities A and C? Draw a qualitive graph to describe the relation between A and C. Assumeing B is constante.

asked by Help on October 2, 2016
92. ## College Chemistry

Please help me. I have worked on this for 2 days. I don't understand the ratio of this equation.4Na+O2 to 2Na2O. for question: How many grams of Na2O are produced when 81.ograms of Na reacts?

asked by Linda on March 7, 2014
93. ## Parametric derivatie help plz

Find the equation of the line tangent to the parametric curve define by x=cos2t and y=sin3t and t=pi/12 plz i don't no where to start from show working

asked by Collins on October 28, 2015
94. ## chemistry need help so bad seriously help plz

Use Rydbuz equation to calculate the wavelength of the third line in the paschen series of the hydrogen spectrum.give ur answer in Nm. RH=2.18 * 10^-18j, H=6.63 * 10^-34J. Plz help m

asked by weyeremi on March 30, 2017
95. ## chemistry

I need to write an equation that takes place at a temp of 400 K and with a catalyst of iron to make ammonia gas from gaseous nitrogen and hydrogen

asked by sheila on May 21, 2011
96. ## Chemistry

Write the molecular equation for the combination of aqueous solutions of sodium chloride and silver nitrate. Enter your answer as the sum of all coefficients.

asked by Melinda on October 10, 2012
97. ## Chemistry

Write an equation that represents how dihydrogen phosphate ion (H2PO4-) behaves as an Arrhenius acid. ( Be sure to include the correct charges for ions.)

asked by Michelle on April 21, 2013
98. ## Chemistry

Help with the equation for the synthesis 2-chlorobutane from 1-butene and hydrogen chloride for bromobenzene from benzene and bromine I came up with 1C6H6+1Br2->1C5H6Br+1HBr is this correct?

asked by mary on June 8, 2010
99. ## PHYSICS!!!

A net force of 30 N is applied to a 10 kg object, which starts at rest. What is the magnitude of its momentum after 3.0 seconds? Can someone please explain this as you go through the steps? I already know the equation is p=mv and I know that mass is 10kg

asked by Christina on June 2, 2012
100. ## More trig

Use the Quadratic Formula to solve the equation in the interval [0,2pi). Then use a graphing utility to approximate the angle x. (1) 5/(tanx+secx) (2) 4cos^2x-4cosx-1=0 Thank you.

asked by Poindexter on November 17, 2008