# Calculate the pH of the solute in an aqueous solution of 0.0047 M codeine, if the pKa of itsconjugate acid is 8.21. What is the percentage protonation of the solute?

46,915 questions, page 343
1. ## Mcmaster

A pendulum consists of an object of mass 2.26 kg that hangs at the end of a massless bar, a distance 2.02 m from the pivot point. Calculate the magnitude of the torque due to gravity about the pivot point if the bar makes an angle of 54° with the

asked by Gabbie on March 7, 2012
2. ## physics

The flywheel of a steam engine begins to rotate from rest with a constant angular acceleration of 1.41 rad/s2. It accelerates for 25.5 s, then maintains a constant angular velocity. Calculate the total angle through which the wheel has turned 65.5 s after

asked by qwertzuiop on February 10, 2012
3. ## Physics

A car traveling at constant speed safely negotiates a frictionless banked curved. Calculate the speed of the car when the road is banked at 20 degrees and the radius of its path is 50 meters. HINT – Do not rotate your axes. Answer v = 13.35 m/s

asked by Anonymous on November 25, 2012
4. ## PHYSIC

IN YOUNG DOUBLE SLIT EXPERIMENT LIHGIT WAVE LENGTH 620NM is ured on 2slit are 0.3 mm interference fringes observed on the screen are 1.3 a) calculate the distance fr6 the screen and the fringd width if the distance double

asked by RAJ on June 6, 2016
5. ## physics

Consider a frictionless track as shown in the figure below. A block of mass m1 = 5.95 kg is released from A. It makes a head on elastic collision at B with a block of mass m2 = 10.0 kg that is initially at rest. Calculate the maximum height to which m1

asked by chuck on October 28, 2010
6. ## Physics

Calculate the kinetic energy that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used

asked by Ashley on January 30, 2013
7. ## Calculus- Reiny

Thanks for the help, but do you understand what Im suppoosed to graph on 2D d) Use a graphing calculator to sketch the graph of y = V(x). Use the viewing window [0, 24, 4] by [-2500, 4000, 500]. Then use the 2 nd – TRACE – maximum feature to calculate

asked by James on June 13, 2016
8. ## Environmental engineering

The company you work for plans to release a waste stream containing 7 mg/L of benzaldehyde . Assuming that benzaldehyde degrades according to the reaction: C7H6O + 8O2 → 7CO2 + 3H2O Calculate the theoretical carbonaceous oxygen demand of this waste

asked by Jazmin on February 26, 2011
9. ## fluid mechanics

I have got differential pressure from an inclined manometer to be 2.8kPa and density of the fluid is 784kg/m^3. I need to calculate the manometer datum height. how do i do tht?? i already did it using formula pressure=density*g*h but i want ans to be 0.165

asked by Nir on May 31, 2010
10. ## physic

A 25 gm bullet is fired into a 2.25kg ballistic pendulum and becomes embedded in it. If the pendulum moves a vertical distance of 10cm, calculate: A. The speed of the system after collision B. The initial speed of the bullet C. The percentage of the energy

asked by piggy on February 5, 2015
11. ## Physics

Calculate the kinetic energy that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used

asked by BrookeNeed on November 18, 2016
12. ## Science (Chemistry)

"Calculate the amount of heat (kcal) released when 18.0 g (grams) of steam are condensed at 100.0 C and the resulting water is frozen and cooled to 25.0 C." The only problem that I'm having is the amount of physical and temperature changes that there are.

asked by Sebastian on October 10, 2016
13. ## physic

A small fly wheel fitted to a motor with a moment of inertia of 80 kg m² slows down from 9000 rpm to 5500 rpm in 7.5 seconds. For the fly wheel, calculate: • The rate of deceleration which you can assume to be constant • The braking torque.

asked by john on April 29, 2017
14. ## PHYSICS

Calculate the kinetic energy that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used

asked by Anonymous on November 3, 2015
15. ## Calculus

In the diagram below, the y-coordinate of point P is increasing at a rate of 4 units per minute while point Q remains in its fixed position. Find the rate of change of angle, in radians per minute, when y = 20. y ^ | P (0, y) | | | | |---| |___|________ Q

asked by Katie on February 6, 2011
16. ## Physics

A ball on the end of a string is revolved at a uniform rate in a vertical circle of radius 72.0 cm, as shown in Fig. 5–33. If its speed is .4 00 m s and its mass is 0.300 kg, calculate the tension in the string when the ball is (a) at the top of its

asked by helpme on February 6, 2011
17. ## Physic

A ball of mass 1000g moving with 7m/s impinges another ball of twice its own mass and moving with 1/6th of its own velocity and moves in the opposite direction. If the coefficient of restitution is 0.75, calculate the velocities of the two balls after

asked by Abdu on November 24, 2016
18. ## Physics

A ball on the end of a string is cleverly revolved at a uniform rate in a vertical circle of radius 85.0cm. If its speed is 4.15 m/s and its mass is 0.300 kg, calculate the tension in the string when the ball is (a) at the top of its path, and (b) at the

asked by Angie on November 20, 2013
19. ## Chemistry

An element has ccp packing with a face-centered cubic unit cell. Its density is 12400 kg/m3 and the unit cell volume is 5.50 x 10-29 m3. Calculate the molar mass (g/mol) of the element to three significant figures. Please explain how you come to the

asked by Luc on February 9, 2010
20. ## Chemistry

Calculate the number of grams of water produced from 30 g of oxygen gas. List only the number of grams of water. First, you will need to balance the equation above. Round to the nearest hundredth. And, as always, don't forget the units.C6H10+O2---->CO2+H2O

asked by Jarred on August 5, 2010
21. ## physics

A laden lorry of mass 3000kg travelling due east at 40 m.s -1 collides head on with a large truck of mass 2000kg travelling at 30 m.s -1. the two vehicles combine during the collision. Calculate the velocity with which the two wrecks move after collision.]

asked by Claudia on February 10, 2011
22. ## camestry

Calculate the number of grams of calcium chloride (CaCl2) needed to react with excess silver nitrate (AgNO3) to produce 6.60 g of silver chloride (AgCl). The equation for the reaction is given below: CaCl2 + 2AgNO3 → 2AgCl + Ca(NO3)2

asked by mohammed on November 5, 2012
23. ## Physic

A 25 gm bullet is fired into a 2.25kg ballistic pendulum and becomes embedded in it. If the pendulum moves a vertical distance of 10cm, calculate: A. The speed of the system after collision B. The initial speed of the bullet C. The percentage of the energy

asked by tason on February 5, 2015
24. ## Physics

A ball on the end of a string is revolved at a uniform rate in a vertical circle of radius 72.0m, as shown in figure. If it's sped is 4.00 m/s and its mass is .300kg. Calculate the tension in the string when the ball is a). at the top of its path and b).

asked by Emily Grossman on February 22, 2011
25. ## physics

The flywheel of a steam engine begins to rotate from rest with a constant angular acceleration of 1.45 rad/s2. It accelerates for 29.5 s, then maintains a constant angular velocity. Calculate the total angle through which the wheel has turned 63.7 s after

asked by Sue on September 22, 2013
26. ## science

A bullet with a mass of 7.11 g and a speed of 774 m/s penetrates a tree horizontally to a depth of 1.85 cm. Assume that a constant frictional force stops the bullet. Calculate the magnitude of this frictional force. Try energy considerations. Answer in

asked by jason on November 16, 2012
27. ## Science (Chemistry)

"Calculate the amount of heat (kcal) released when 18.0 g (grams) of steam are condensed at 100.0 C and the resulting water is frozen and cooled to 25.0 C." The only problem that I'm having is the amount of physical and temperature changes that there are.

asked by Sebastian on October 10, 2016
28. ## Physics

A waterfall is 1260m high. calculate the change in temperature of the quantity of water that falls from the top to the bottom of the waterfall( neglect heat losses to the surrounding) take g to be 10m/s and specific.heat capacity of water to be 4200j/kg/k.

asked by Blue on March 2, 2016
29. ## Physics

Ive tried numerous methods, but I cant seem to get this right. Please help, and explain step by step. An object's position is given by x=bt+ct^3, where b=1.50m/s and c=0.640m/s3. To study the limiting process leading to the instantaneous velocity,

asked by Ronnie on January 14, 2016

I need to calculate the valueof Kc for 5 test tubes for an experiment that I completed on determination of Kc. The equation used was Fe^3+ + SCN^-= FeSCN^2+ After creating an ice table for the first test tube my values for Fe and SCN were 6.5e-4M and for

asked by Hannah on March 6, 2012
31. ## Chemistry

Calculate the standard cell potential for each of the electrochemical cells? What would the answers be to something like this? If someone could work out the answer I would really appreciate it. My online hw keeps telling me its wrong.

asked by John on April 12, 2014
32. ## Chemistry

A sample of an ideal gas at 15.0 atm and 10.0 L is allowed to expand against a constant external pressure of 2.00 atm at a constant temperature. Calculate the work in units of kJ for the gas expansion. (Hint: Boyle's law applies) Please explain thoroughly!

asked by Jack on October 3, 2010
33. ## Chemistry

A piece of copper of mass 21.3 g at 106.0 °C is placed in a vessel of negligible heat capacity but containing 53.0 g of water at 19.3 °C. Calculate the final temperature of the water. I keep getting 22 celsius and I'm not sure where I'm going wrong. I

asked by Jessica on November 4, 2014
34. ## Physics,chemistry,maths

On turning a corner a car drIver driving at 36 km per hour find a child on the road 55 metre ahead.he immediately applies brakes so as stop within 5 metre. Calculate the retardation produced and the time taken by the car to stop.

asked by Anamika roy on August 3, 2017
35. ## Math

On January 31, a count of ending inventory was completed, and 7,200 units were on hand. Using the periodic inventory system, calculate the cost of goods sold and ending inventory using LIFO, FIFO, and weighted-average inventory methods.

asked by Theresa on February 8, 2015
36. ## Chemistry

Using Hess’s Law with the following data: N2(g) + O2(g) = 2NO(g) Del(H) = 180.7kj 2NO(g) + O2(g) = 2NO2(g) Del(H)= -113.1kj 2N2O(g) = 2N2(g)+ O2(g) Del(H)=-163.2kj Calculate Del(H) for the reaction: N2O(g) + NO2(g) = 3NO(g)

asked by Dan on July 29, 2014
37. ## chemistry

A sample of an ideal gas at 15.0 atm and 10.0 L is allowed to expand against a constant external pressure of 2.00 atm at a constant temperature. Calculate the work in units of kJ for the gas expansion. (Hint: Boyle's law applies) Please explain thoroughly!

asked by Jack on October 4, 2010
38. ## Physics

A car traveling at constant speed safely negotiates a frictionless banked curved. Calculate the speed of the car when the road is banked at 20 degrees and the radius of its path is 50 meters. (HINT - Do not rotate your axes) Answer v=13.35 m/s

asked by Anonymous on November 21, 2012
39. ## Chem 225

Calculate the amount of isopentyl acetate that should be present in the reaction mixture at equilibrium based on 300 mmol of acetic acid and 150 mmol of isopentyl alcohol as starting quantities. Use equilibrium constant of 4.2 for this calculation.

asked by Dee-Dee on October 12, 2015
40. ## Brain excel

R and S are two observation posts on the same horizontal ground as the foot P of a vertical tower PQ.The tower is 18m due north of S and 24m east of R.The angle of elevation of Q from S is 35degree.calculate the height pQ,the distance RS,the angle of

asked by Zenny on November 11, 2015
41. ## math

Cand D are two observation posts on the same horizontal ground at the foot A of a vertical tower AB.the tower is 18m due north of D and 24m east of C.the angle of elevation of B from D is 35¡ã.calculate to three s.f the height AB,distance CD,angle of

asked by dayo on June 22, 2017
42. ## Bio/CHEM

11. You need to make a 1:8 ratio of DNA of two DNA types A and B (A:B). Your total aliquot should be 2ng/26 ìL. For each of the following sets, calculate how much of each extract you should use and how much TE-4: a. Extract A: 2.5 ng/20 ìL, Extract B:

asked by Remy on May 24, 2013
43. ## statistics

A jar contains 2 red balls, 2 blue balls, 2 green balls and 1 orange ball. Balls are randomly selected, without replacement, until 2 of the same colour are obtained. Calculate the probability that more than 3 balls must be selected.

asked by peter on July 2, 2016
44. ## statistics

A jar contains 2 red balls, 2 blue balls, 2 green balls and 1 orange ball. Balls are randomly selected, without replacement, until 2 of the same colour are obtained. Calculate the probability that more than 3 balls must be selected.

asked by Koala on August 7, 2014
45. ## chem

How many grams of iron metal do you expect to be produced when 245 grams of an 80.5 percent by mass iron (II) nitrate solution reacts with excess aluminum metal? Show all of the work needed to solve this problem. 2 Al (s) + 3 Fe(NO3)2 (aq) 3 Fe (s) + 2

asked by bryan on January 17, 2012
46. ## Ethics

Which of the following was Tolstoys solution to the intense feelings of lifes utter lack of true and lasting meaning? my answer is C a. To devote his life to being an author. b. To devote his life to his family. c. An irrational faith in God. d. A rational

asked by Annmarie on February 18, 2014
47. ## Chemistry

Carbon tetrachloride (CCl4) and benzene (C6H6) form ideal solutions. Consider an equimolar solution of CCl4 and C6H6 at 25°C. The vapor above this solutionis collected and condensed. Using the following data, determine the composition in mole fraction of

asked by MInx on December 7, 2011
48. ## Chemistry

Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.300 M phosphoric acid solution. kPa1: 2.16 kPa2: 7.21 kPa3:12.32 [H3PO4] = ?

asked by Paula on March 10, 2013
49. ## chemistry

QUESTION 4 Data Set 3: 47.65 mL of a standard 0.1000 mol L–1 HCl solution is used to titrate a 0.3827 g sample containing NaOH and other impurities. None of the impurities reacted with the HCl. What is the mass of NaOH in the sample? a. 0.1737 g b.

asked by jess on May 29, 2016
50. ## Analytical Chem

Use activity coefficients to find the concentration of hydrogen ions in a solution of 65.0 mM butanoic acid and 0.05 M NaCl. The ionization constant of butanoic acid is Ka = 1.52 × 10-5. Take the size of C3H7COO– to be 500 pm. Find [H+], pH, and alpha.

asked by Anonymous on September 22, 2014
51. ## chem

an (aq) ammonium chloride solution, rather than H2SO4, is used in the hydrolsis of the magnesium complex of 1,1-diphenylethanol to ensure that no acid catalyed dehydration occurs. write the chemical structure of the dehydration product from

asked by yen on March 7, 2009
52. ## data management gr.12

In how many ways can a committee of 8 members be chosen from 7 males and 9 females if the committee must contain at least 3 males? Please verify if my solution is correct: total# of 8 members 16C8 #with NO males 7C8 # with at least 3 males (7C3 x 4C2)+

asked by Anonymous on December 22, 2016
53. ## Physics

A 25 kg box is along a horizontal floor and a force of 400 N pushes the box with an angle of 50 degree with the horizontal. Starting from rest, the box achieves a velocity of 2 m/s in a time of 4 seconds. Find the coefficient of sliding friction between

asked by Shekinah on April 10, 2016
54. ## Speech

I have to give a problem-solution speech on "Global Warming" what would i put into this? I need to point out some good solutions to the problem. It has to be a really interesting speech for the audience any pointers would be good. I also need a power point

asked by Rina on February 21, 2009
55. ## Chemistry

Which of the following solutes, dissolved in 1000g of water, would provide a solution would the lowest freezing point? .030 mol of BaCl2, CO(NH2)2, CaSO4, CH3COOH, or .030 mol of NH4NO3 Again, the steps needed to determine for the freezing point.

asked by Marcus on February 19, 2013
56. ## math

The formula T=2*pi*sqrt[L/32] gives the period of a pendulum of length l feet. The period P is the number of seconds it takes for the pendulum to swing back and forth once. Suppose we want a pendulum to complete three periods in 2 seconds. How long should

asked by Gabi on April 11, 2011
57. ## chemistry

After isolating the sulfonated product, the filtrate volume is found to be 25.25 mL. A dilution using 1 mL of filtrate and 99 mL of water gives a solution with an absorbance of 0.427. How many moles of indigo carmine were produced? (Molar absorptivity of

asked by Michael on September 22, 2014
58. ## Dynamics

The rated speed of the highway curve of 200 ft radius is 30 mph. If the coefficient of friction between the tires and the road is 0.6, what is the maximum speed at which a car can round the curve without skidding? show solution step by step show FBD (if

asked by 20 on July 14, 2018
59. ## Dr. Bob...Chemistry

you just answered a question for me, but the following are my answers to choose from. it was the 2nd question that I posted. about hydrocloric acid solution mixing with sodium bicarbonate. So, my answers to choose from are gas evolution, precipitation,

asked by Coug on November 20, 2009
60. ## chemistry

Glycerin, C3H8O3, is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 159 g glycerin to 338 mL H2O at 39.8oC? The vapor pressure of pure water at 39.8oC is 54.74 torr and its density is 0.992 g/cm3.

asked by rose on October 5, 2016
61. ## Chemistry

If it requires 23.4 milliliters of 0.65 molar barium hydroxide to neutralize 42.5 milliliters of nitric acid, solve for the molarity of the nitric acid solution. Show all of the work used to solve this problem. Unbalanced equation: Ba(OH)2 + HNO3 ->

asked by Lilly on March 15, 2016
62. ## Chemistry

The molar mass of an unknown salt is 63.5. If 4.81 g is added to 81.1 mL of water the temperature changes from 20.95oC to 21.62oC. What is the molar heat of solution (J/mol) of the salt? (Assume all of the heat is transfered to the water) Express your

asked by John on March 7, 2012
63. ## Chemistry

Phosphoric acid, H3PO4(aq), is a triprotic acid, meaning that one molecule of the acid has three acidic protons. Estimate the pH, and the concentrations of all species in a 0.100 M phosphoric acid solution. pKa1 = 2.16 pKa2 = 7.21 pKa3 = 12.32 [H3PO4] = ?

asked by Nancy on February 26, 2013
64. ## math

Decide whether you would use a permutation, a combination, or neither. Next, write the solution using permutation notation or combination notation, if possible, and, finally, answer the question. A club with 34 members is to select five officers

asked by leelee kay on June 3, 2014
65. ## Science

If it requires 23.4 milliliters of 0.65 molar barium hydroxide to neutralize 42.5 milliliters of nitric acid, solve for the molarity of the nitric acid solution. Show all of the work used to solve this problem. Unbalanced equation: Ba(OH)2 + HNO3 ->

asked by Elain on March 15, 2016
66. ## Chemistry

Describe how you would prepare the following two solutions. Be sure to include the type of glassware which you would use and as much detail as necessary for someone to actually prepare the solution using good laboratory technique. • 250 mLs of a 5% NaCl

asked by Joe on November 7, 2017
67. ## Maths

I got this question, and found what I believe to be the solution, but want it confirmed. I started with: log[base5](2x+1) + log[base5](x-1) = 1 And used the product law: log[base5]((2x+1)(x-1)) = 1 log[base5](2x^2-x-1) = 1 Then I changed to exponential

asked by anonymous on June 8, 2010

Describe how you would prepare the following two solutions. Be sure to include the type of glassware which you would use and as much detail as necessary for someone to actually prepare the solution using good laboratory technique. • 250 mLs of a 5% NaCl

asked by Joe on November 7, 2017
69. ## algebra1

Find the product: (x + 5)2 12 Answer: Referring to the figure, find an expression for the area. 13 Answer: Use the zero-product property to solve the equation: (x + 4)(x - 2) = 0 *NOTE: Applicable to this and all other questions-- For any solution that

asked by peaches williams on June 7, 2011
70. ## Chemistry

Sodium sulfate is slowly added to a solution containing 0.0500 M Ca^2+ (aq) and 0.0390 M Ag^+ (aq). What will be the concentration of Ca^2+ (aq) when Ag2SO4(s) begins to precipitate? What percentage of the Ca^2+ (aq) can be separated from the Ag^+ (aq) by

asked by Anon on March 17, 2013
71. ## Thank you Ann (kinematics)

Thank you Ann! I had the equations and really was closing in on the answer... (stopping for 23 s is what really got me confused) in either case, the displacement for a) is 888 m ! Now I'll try to calculate (b). Thank you much! P.S. This is in response to

asked by eric (new chem or physics prob. in) on January 31, 2007
72. ## Biochem

Calculate the amount of Tris(hydroxlmethyl)aminomethane(Tris) necessary to make 100mL of a 0.100 M Tris buffer that is equimolar in Tris-base (MW=121.1 g/mol) and Tris-HCL (MW= 157.6g/mol)

asked by bugbabe623 on September 10, 2008
73. ## Chemistry

K=1.6x10^-5 mol/L for the following reaction 2NOCl(g).... 2 NO(g) + Cl2(g) Calculate the concentrations of all species at equilibrium for each of the following original mixtures E) 2.4 mol of NOCl, 2.4 mol of NO, and 1.2 mol Cl2 in a 1.0 L flask F)1.9

asked by AMANDA on November 20, 2007
74. ## chemistry

a radioactive material is undergoin nuclear decay. After 40 minutes, 25% of the sample remains. What is the half life of the sample? Pls say the formula how to calculate it a)10 mins b) 20 mins c) 40 mins d)80 mins e) 160 mins

asked by star on May 28, 2012
75. ## Math

1. Should the census figures be adjusted for the undercount? If so, how? If this solution introduces errors of its own, estimate how large they are, compared to the undercounts. 2. What method should Congress select for apportioning the House of

asked by David Earnest on March 6, 2010
76. ## Chemistry

Write a balanced net ionic reaction for the reduction of cupric ion (Cu2+) by hydroxylamine (NH2OH) in acid solution, using the smallest integer coefficients. (Do not include symbols for state of matter in your answer). in order for this to reduce Cu+2 to

asked by Joseph on October 19, 2015
77. ## Chemistry

You have 2 chemicals A (solid), but you do not know the exact composition od either one of them. You do know that all together, there is SOME combination of sodium, barium, chloride and phosphate (PO4^-3) present. You disolve both chemicals in water. then

asked by Anonymous on July 18, 2010
78. ## chemistry

addition of 1.280g of zinc metal to 100mL of 0.3917 M HCl in a coffee-cup calorimeter causes the temperature to increase from 1 degrees celsius to 22.11 degrees celsius. What is the value of the change of Hrxn for the following equation: Zn(s) +

asked by xx on November 13, 2014
79. ## english COM215 axia

okay for this scenario i have to write at least a 350 word response, and decide to whom the solution should be written to and why, and whether it should be email, memo, or letter: The trip scheduled for mexico during spring break has been cancelled due to

asked by Michelle on August 24, 2007
80. ## Chemistry-Gases

A common laboratory preparation of hydrogen on a small scale uses the reaction of zinc with hydrochloric acid. Zinc chloride is the other product. (a) If 13.0 L of H2 at 765 torr and 20.0 °C is wanted, how many grams of zinc are needed, in theory? (b) If

asked by Anonymous on April 2, 2014
81. ## Chemistry

When dilute nitric acid was added to a solution of one of the following chemicals, a gas was evolved. This gas turned a drop of limewater, Ca(OH)2, cloudy, due to the formation of a white precipitate. The chemical was.... a. the household ammonia NH3 b.

asked by Caroline on April 12, 2009
82. ## Chemistry

35 grams of sodium phosphate are mixed with enough water to make 3.5L of solution having a densityof 1.045g/mol. Find the concentration of sodium phosphate in ppm. Using the same information, find the molarity of the sodium and phosphate ions.

asked by Kristen on February 15, 2012
83. ## chemistry

Sodium carbonate (Na2CO3) has a molar weight of 105.9885 g/mol. A solution contains 50. mM sodium ions and 25 mM carbonate ions. What is the concentration of sodium carbonate in the solutions as expressed as mass/volume percentage?

asked by Anonymous on June 20, 2017
84. ## AP Chemistry

There is an unknown amount of unlabelled monoprotic acid in an unknown amount of water titrated with a sample with a solution of NaOH of unknown molarity. After adding 10.0 mL of NaOH, the pH=5.0. The equivalence point is 32.22 mL of NaOH. What is the Ka?

asked by Ben on March 8, 2011
85. ## Redox Reaction

In an acidic solution, manganese(II) ion is oxidized to permanganate ion by bismuthate ion, BiO3-. In the reaction, BiO3- is reduced to Bi3+. How many milligrams of NaBiO3 are needed to oxidize the manganese in 30.2 mg of manganese(II) sulfate?

asked by Kelly on April 19, 2015
86. ## science

Erin must perform a science experiment. She needs to dissolve 10 g of salt in 250 ml of water. She measures the water incorrectly and dissolves the 10 g of salt in 350 ml of water. Now she has no more salt. Explain what Erin can do to make the solution

asked by astrid on April 29, 2008
87. ## chemistry

Ravi prepared a solution of sodium chloride by mixing 5.85g of salt in 1 liter of water. a)find molar mass of sodium chloride b)find number of moles of sodium chloride dissolved.

asked by hamida on January 5, 2015
88. ## chemistry

How many moles of NaOH are in 23.5 mL of a 1.50 M solution? 1. 0.0353 moles 2. 35.26 moles 3. 16.7 moles 4. 0.0235 moles

asked by katie on November 29, 2011
89. ## Math

How many solutions does the equation cosx + 1/2 = 1 have for 0

asked by Jake on January 25, 2012
90. ## fin

The following tabulation gives earnings per share figures for the Foust Company during the preceding 10 years. The firm’s common stock, 7.8 million shares outstanding, is now (1/1/03) selling for \$65 per share, and the expected dividend at the end of the

asked by HELP on September 8, 2007
91. ## physics

A mass attached to a spring executes simple harmonic motion in a horizontal plane with an amplitude of 1.07 m. At a point 0.4815 m away from the equilibrium, the mass has speed 3.87 m/s. What is the period of oscillation of the mass? Consider equations for

asked by eric on April 19, 2010
92. ## Physics

The mass of a sports car is 1100 kg. The shape of the car is such that the aerodynamic drag coefficient is 0.240 and the frontal area is 2.40 m2. Neglecting all other sources of friction, calculate the initial acceleration of the car ,if it has been

asked by Simi on July 10, 2010
93. ## Chemistry (concentration)

Iron fluoride (FeF2) dissociates according to the following equation: FeF2(s) ⇌ Fe^2+(aq) + 2 F^–(aq) A sample of iron fluoride (FeF2) is dissolved in water, and a saturated solution is obtained. The [Fe^2+] is measured to be 2.05 × 10^–4 mol/L.

asked by Summer on March 30, 2018
94. ## Chemistry

A 5.0-g Sample of KBr at 25.0 degrees celsius dissolves 25.0 mL of water also at 25.0 degrees celsius. The final equilibrium temperature of the resulting soltution is 18.1 degrees celsius. What is the enthalpy of of solution in kilojoules per mole of KBr?

asked by Sam on March 20, 2013
95. ## chemistry

What is the pH of the solution created by combining 2.80 mL of the 0.10 M NaOH(aq) with 8.00 mL of the 0.10 M HCl(aq)? with 8.00 mL of the 0.10 M HC2H3O2(aq)? mL of NaOH pH w/HCl pH w/HC2H3O2 2.80 ? ? okay, so i tried m1v1=m2v2 and when i got m2 i would

asked by UN on July 9, 2008
96. ## Chem 219

If 48.9g of barium chloride dihydrate, BaCl2.2H20, was treated with excess silver nitrate solution. (show formula) a). how many moles of silver chloride precipitated? b). how many grams of silver chloride precipitated? thank you!

asked by Chels on February 8, 2011
97. ## physics

the distance between a loudspeaker and the left ear of a listener is 2.70 m a) calculate the time required for sound to travel this distance if the air temperature is 20oC. b) assuming that the sound frequency is 523 Hz, how many wavelengths of sound are

asked by Joe on November 18, 2012
98. ## Physics

A singly charged positive ion has a mass of 2.74 10-26 kg. After being accelerated through a potential difference of 268 V, the ion enters a magnetic field of 0.450 T, in a direction perpendicular to the field. Calculate the radius of the ion's path in the

asked by Joe on April 17, 2013
99. ## Physical Chemistry

Calculate the work, w, (in J) when 0.6 litre of an ideal gas at an initial pressure of 91.5 atm is expanded isothermally to a final pressure of 2.15 atm against a constant external pressure of 2.15 atm. I got -130.71 J, but apparently it is wrong. Help is

asked by Cole on January 18, 2016
100. ## Science

A box of mass 50kg is placed on an inclined plane. When the angle of the plane is increased to 30°, the box begins to slide downward. Calculate the coefficient of statics friction b/w the plane and box . Draw the free body diagram .

asked by Jitender on February 15, 2017