# 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 254
1. ## Chem

Given that 277J of heat are absorbed when 1.12g of sodium nitrate are dissolved in water, calculate the heat of reaction.

asked by Shirley on July 15, 2012
2. ## physics

A 225-kg box is pushed horizontally with a force of 620N. If the coefficient of friction is 0.20, calculate the acceleration of the box.

asked by john on April 23, 2014
3. ## statistics

Calculate SS, variance, and standard deviation for the following population of N _ 7 scores: 8, 1, 4, 3, 5, 3, 4. (Note: The definitional formula works well with these scores.)

asked by Liz on June 22, 2011
4. ## paul

A stock will provide a rate of return of either –20% or +28% . 1. If both possibilities are equally likely, calculate the expected return and standard deviation.

asked by john on April 23, 2010
5. ## statistics

Calculate SS, variance, and standard deviation for the following sample of n _ 4 scores: 3, 1, 1, 1. (Note: The computational formula works well with these scores.)

asked by Liz on June 22, 2011
6. ## Science

A pump is used to lift 500 kg of water from a depth of 80 m in 10 seconds.Calculate the power rating of the pump if it's efficiency is 40% . Take g=10 m/ s*s.

asked by Swati on February 7, 2017
7. ## science

An automobile is pulled by a horizontal tow line, with a force of 900 N. If its acceleration is 1.0 m/s2, calculate the mass of the automobile.

asked by tash on January 30, 2013
8. ## chemistry

How do you calculate deltaHf using the # of moles from a balanced equation? How do you connect the Law of Conservation of Energy to a Thermochemical Equation? Thanks so much!

asked by K on April 29, 2013
9. ## science

Calculate the EMF of the cell CR|Cr3+(0.1M)||Fe2+(0.1M)|Fe Cell reaction- 2Cr(s)+3Fe2+(aq)->2Cr3+(aq)+3Fe(s)

asked by Rasilu on April 26, 2016
10. ## maths /science

A body calling from rest has a velocity of 25m/s at given instant. Calculate 1 the distance the body has fallen 2 the time taken

asked by christina on September 28, 2016
11. ## physics

A 250-kg crate is pushed horizontally with a force of 710 N. If the coefficient of friction is 0.20, calculate the acceleration of the crate.

asked by das on October 18, 2010
12. ## chemistry

a. Determine the density of a cube of copper with a length of 5.00 cm and a mass of 1,112.50 g. b. Calculate the number of atoms in the cube

asked by Mike on July 20, 2014
13. ## math

the total surface of rectangular solid is 130cm^2 .if the solid is 7cm long nd 5cmwide. calculate the height

asked by timi on May 9, 2019
14. ## Chem

A block of metal has a width of 3.2 cm, a length of 17.1 cm, and height of 4.3cm . Its mass is 1.2kg . Calculate the density of the metal.

asked by Cf on September 16, 2013
15. ## chemistry

Help me solve it. Step by step please The value of kp at 20°c for the reaction 2NO(g) +Cl2(g) 2NOCl(g) is 1.9x10^3 atm-1 calculate the value of KC at the same temperature.

asked by john on December 6, 2015

Andrew borrows $79,500 for 5 months on 6.30% interest rate in his saving account. Calculate the simple interest? asked by Anonymous on April 2, 2014 17. ## chemistry When irradiated with a radiation of wavelength 58.4 nm the electron of H atom was ejected with kinetic energy 7.6 eV. Calculate the ionization energy. asked by kamila t arakkal on April 26, 2016 18. ## engineering If faucet is dripping at a rate of one drop per second and each drop contains 0.150 milliliters. Calculate how much water will be lost in 1 year. asked by Maria on January 14, 2011 19. ## physics calculate the total pressure at an ocean depth of 6000 m (the depth at which the wreck of the titanic was found) in both pascals & lb/in^2 asked by john on March 20, 2010 20. ## Physics d1 = 2.53 cm +/- .05 cm d2 = 1.753 m +/- .001 m 0 = 23.5 degrees +/- .5 degrees v1 = 1.55 m/s +/- .15 m/s Using the measured quantities above, calculate the following. Express the uncertainty calculated value. d1 (tan (0)) asked by Joy on November 11, 2013 21. ## Chemistry Calculate the longest wavelength of light that can break a H-O bond. The bond enthalpy of formation is 463 kj/mol asked by Angelina on April 8, 2011 22. ## chemistry Calculate the energy in joules per photon of red light having a wavelength 655 nm. What is the energy of 1 mol of these photons? asked by ashley b on June 23, 2011 23. ## Calculus (Motion with Vector functions) 1. What are the magnitude and direction angle for the vector u= 2. Calculate the speed of a particle in the xy-plane with positive vector r(t)=(4-t^2, 6t) at the point (0,12). asked by Angela on January 22, 2018 24. ## Science A projectile has a range of 50m and reaches a maximum height of 10m. Calculate the angle at which the projectile is fired. asked by Gash on February 6, 2019 25. ## Chem A block of metal has a width of 3.2 cm , a length of 17.1 cm , and height of 5.2cm . Its mass is 1.2kg . Calculate the density of the metal asked by Jillian on September 12, 2013 26. ## physics The surface area and the average depth of the Pacific Ocean are 1.8 x 10 8 km 2 and 3.9 x 10 3 m, respectively. Calculate the volume of water in the ocean in liters. asked by Latrese on September 25, 2011 27. ## chemistry QUESTION 9 The number of moles of the reagent in excess can be used to calculate the moles of the products of the reaction. TRUE FALSE asked by Anonymous on July 11, 2016 28. ## chemistry The heat of vaporization of bromine at its boiling point (59.6 °C) at 1.00 atm is 29.54 kJ/mol. Calculate the vapor pressure of bromine at 37.8 °C. asked by WLP on January 22, 2012 29. ## Chemistry Calculate the mass percent composition of carbon in each the following carbon compounds. C2H2 C3H6 C2H6 C2H6O asked by Amee on March 4, 2013 30. ## SS How often do banks calculate interests on accounts with simple interest? daily weekly monthly yearly yearly? asked by Anonymous on January 31, 2014 31. ## Biochemistry Two molecules of DNA are the same size, but differ in base composition. One molecule contains 20 % (A + T) while the other contains 60 % (A + T). Which molecule has the higher T m? Why?(The m is a subscript of T) I'm not sure what T m is..or how to asked by student on September 17, 2009 32. ## Physics Four equal charges Q=2*10^-8coulumb are placed at the corners of a square of side 60cm.calculate the potential at the centre of the square. asked by Ayodele on April 8, 2010 33. ## Chemistry Given that KH for CO gas at 25 OC is 9.71 x10-4 mol.L-1.atm-1. Calculate the mass of CO that would dissolve in 1.00 L of H2O if the partial pressure of CO is 1.38 atm. asked by Chelsea on February 15, 2011 34. ## geography Calculate the gradient of a road (4km) intervals from a given roundabout the different height between the two end point the road is 400mm? asked by jamilu abubakar sadiq on April 23, 2016 35. ## Chemistry calculate the bond energy for diatomic oxygen O2 given that standard enthalpy of atomization of oxygen (ΔH) = 249.17KJ asked by Solomon on February 29, 2016 36. ## Chemistry A 0.22-caliber handgun fires a 27-{\rm g} bullet at a velocity of 765 {\rm m}/{\rm s}. Part A Calculate the de Broglie wavelength of the bullet. asked by Anonymous on June 30, 2012 37. ## Statistics(Please check) calculate the probability of the following: A four, three, or spade from a single draw from a 52 card deck. there are 4 4's so 4/52, 4 3's so 4/52 and then 13/52 spades so 21/52 but and one 4 and one 3 are from spades so minus 2 = 19/52 Is this correct? asked by Hannah on July 23, 2011 38. ## Please Help! Calculus Calculate the speed of a particle traveling in the xy-plane with position vector r(t)=(4-t^2,6t) at the point (0,12). a)2(sqrt13) b)6 c)4(sqrt13) d)52 e)sqrt2 asked by Tony on January 22, 2018 39. ## chemistry calculate the specific heat (j/g C ) for each of the following: -an 18.5-g sample of tin that absorbs 183 J when its temperature inceases from 35.0 degrees C to 78.6 degrees C asked by kelly on September 14, 2010 40. ## physic Calculate the true mass (in vacuum) of a piece of aluminum whose apparent mass is 4.5000 kg when weighed in air. asked by Ash on August 8, 2010 41. ## physics A reistance thermometer has a resistance of 20w at 0°c and 85w at 100°c if it resistance is 52w in medium calculate the corresponding temperature? asked by poppy on April 26, 2019 42. ## physics the mass of the boy is 70kg. calculate the force in newtons acting on the boy due to his deceleration. how do i work this out asked by evie on March 31, 2012 43. ## chemistry Calculate the wavelength (in nanometers) of a photon emitted by a hydrogen atom when its electron drops from the n = 4 state to the n = 3 state. asked by Tanisha on March 23, 2010 44. ## maths The diagonal of a parallelogram 6cm and 8cm long and they intersect at an angle of 55 degrees. calculate the area of the parallelogram asked by Riliwan on November 22, 2016 45. ## statistics the following sample observations were randomly selected: x: 2,5,6,8,9,11,15 y: 22,23,16,18,19,13,12 a)calculate the correlation coefficient, r b) determine the regression equation c) determine the value of Y when X=20 asked by skitter on November 29, 2010 46. ## Physics A car moves along a circular track at 60 kmph. If the radius of the track is 300 m, calculate the acceleration towards the centre asked by Aditya on August 11, 2011 47. ## Chemistry Calculate the pH when 39.0mL of 0.321 of HA is mixed with 39.0mL of 0.321M NaOH where HA is a monoprotic weak acid with Ka= 7.5x10^-5 M ? asked by Jematormal91 on March 24, 2012 48. ## chemistry A system performs 120J work with no heat supplied to it. Calculate the change in internal energy of the system. asked by jaycab on January 23, 2011 49. ## Physics Particles of charge +65, +48, and −95 μC are placed in a line. The center one is L = 60cm from each of the others.Calculate the net force on the left charge due to the other two. asked by Mary on January 31, 2015 50. ## Chem. N2+3H2 2NH3, The equilibrium constant for the chemical equation is Kp = 0.143 at 225 °C. Calculate the value of the Kc for the reaction at 225 °C. asked by Anonymous!! on March 19, 2014 51. ## Physics Calculate the true mass (in vacuum) of a piece of aluminum whose apparent mass is 1.6000kg when weighed in air. asked by Melissa on November 10, 2012 52. ## Chemistry - equm acid base Calculate [H3O+] 0.100 M NaNO2 and 5.00×10−2 M HNO2 so there's no Ka value for NaNO2, it can be ignored 5.6x10^-4 = x^2 / 5.00x10^-2 x = 5.3x10^-3 the answer is incorrect why? Thanks asked by X on March 8, 2018 53. ## Statistics 1. Consider a population with µ=73.6 and 0 = 5.38 (A) Calculate the z-score for x =72.7 from a sample of size 45. (B) Could this z-score be used in calculating probabilities using Table 3 in Appendix B of the text? Why or why not? asked by jane on October 25, 2011 54. ## community umuokpu. Chemistry if 50cm3 of co3 were put in 40cm3 of O2. Determine the gas that would be in excess and calculate the volume of gas that would be unused asked by Tessy on February 9, 2013 55. ## finance You purchase a stock at a price of$73, and a year later the price increases to $85. You also received a dividend of$2.50. Calculate the rate of return.

asked by Anonymous on August 1, 2011
56. ## chemistry

Trying to calculate atoms of O in 2.00 moles of H3PO4.I used 2.00 mol h3po4÷4atoms O then × by 6.022 avrogados# My answer 3.011×10^23

asked by jackson on March 25, 2015
57. ## stats - URGENT!!!!

the following sample observations were randomly selected: x: 2,5,6,8,9,11,15 y: 22,23,16,18,19,13,12 a)calculate the correlation coefficient, r b) determine the regression equation c) determine the value of Y when X=20

asked by skitter on November 30, 2010

you invest $2800 in an account that pays an interest of 5.5%, compounded continuously. calculate the balance of your account after 12 years. asked by heidi on August 6, 2013 59. ## Chemistry For the reaction N2O4(g)=2NO2(g), the value of K at 25 degrees XCelsius is 7.19*10^-3. Calculate N2O4 at equilibrium when NO2 =2.20 *10^122 mol/L? asked by Amy on July 14, 2012 60. ## chemistry 130cm3 of a gas excarts a pressure 750mmhg . calculate it pressure if its volume is increase to 150cm3 at 35oc asked by whiskey on August 9, 2017 61. ## statistics Consider a population with µ=93.3 and σ=5.27. (A) Calculate the z-score for x=94.9 from a sample of size 12. (B) Could this z-score be used in calculating probabilities using Table 3 in Appendix B of the text? Why or why not? asked by Dawn on October 17, 2012 62. ## Statistics Consider a population with µ=73.6 and 0 = 5.38 (A) Calculate the z-score for x =72.7 from a sample of size 45. (B) Could this z-score be used in calculating probabilities using Table 3 in Appendix B of the text? Why or why not? asked by jane on October 24, 2011 63. ## chem 1046 Calculate the boiling point a. 10.5 g FeCl3 in 2.11 102 g water b.4.6% KCl by mass (in water) c.0.140 m MgF2 asked by Anonymous on July 6, 2012 64. ## Astronomy Calculate the approximate circumference of Earths orbit around sun, assuming that orbit is a circle with radius of 1.5 X 10 to the eighth. asked by Kandice on June 11, 2014 65. ## Chemistry the question says: Calculate the mass of soap (NaC17H35COO) which contains 1.25 grams of Carbon. Do I use the percentage composition of soap and the mole? asked by Lauren on June 14, 2016 66. ## physics A constant force of 48.7 N, directed at 34.1° from horizontal, pulls a mass of 15.1 kg horizontally a distance of 2.77 m. Calculate the work done by the force. asked by help on November 21, 2010 67. ## Calculus Consider the region in the plane consisting of points (x, y) satisfying x > 0, y > 0, and lying between the curves y=x^2 +1and y=2x^2 −2. (b) Calculate the area of this region. asked by Mary on May 16, 2016 68. ## college chem 2 The enthalpy of vaporization of liquid diethyl ether is 26.0kJ/mol at 35'C calculate the deltaS' for vapor to liquid asked by shel on March 24, 2014 69. ## Chemistry Calculate the mass in grams for a gold sample that absorbs 245J to change its temperature from 19 degrees to 49 degrees asked by Wendy on March 5, 2011 70. ## Maths the acute angles of a rhombus are 76 degrees if the shorter diagonal is of length 8 cm calculate of the sides of the rhombus to the nearest mm asked by Anita on January 9, 2016 71. ## honors chem high school The topic is Changes in energy Level Calculations. calculate energy value for levels n=1 to n=7; given En=-Rh/n2 R=2.180 x 10 -18 J E=hv h=6.626 x 10 -34 J.s I then need to plot them -- I cannot get started. asked by kate on October 3, 2012 72. ## statistics For a normal distribution, explain why we calculate the probability of a range of numbers instead of the probability of a single number on the lines below? asked by rehena on June 9, 2014 73. ## Chemistry Consider the reaction: 2CO2(g)=2CO(g) + O2(g). A reaction mixture in a 5.0 L flask at a certain temperature. At equilibrium there are 85 g of CO2(g), 1.20 g of CO, and 0.688 g of O2(g). Calculate Kc. asked by Ariel on February 27, 2011 74. ## Physics calculate the work required to launch a satellite from the surface of the earth (radius6380km) to orbit 6000 km above the surface asked by Henry on February 16, 2014 75. ## Chemistry 3NO2 + H2O -> 2HNO3 + NO Calculate the percent yield for the following reaction if 76.8 g of H2O reacted and 125 g of NO were produced. asked by Amanda on November 25, 2014 76. ## Physics A car requires velocity of 36 km /h in 10 sec just after the start . It takes 20 sec to stop . Calculate the acceleration in both the cases asked by Srishti on May 31, 2016 77. ## phyics-universal gravity Calculate the force of gravity on a spacecraft 6400 km (1 earth radii) above the Earth's surface if its mass is 1600 kg. asked by DJ on November 3, 2009 78. ## chemistry when one gram of water solidifies to ice 333.33 j of heat is evolved. calculate enthalpy of fusion of ice? asked by gopal on July 30, 2013 79. ## stats - URGENT!!!! the following sample observations were randomly selected: x: 2,5,6,8,9,11,15 y: 22,23,16,18,19,13,12 a)calculate the correlation coefficient, r b) determine the regression equation c) determine the value of Y when X=20 asked by skitter on November 30, 2010 80. ## chemistry The Kw of water varies with temperature. Calculate the pH of water at 46⁰C with a Kw = 1.219 x 10-14. Show all calculations leading to an answer. asked by Ciaria on March 13, 2015 81. ## physics calculate the acceleration of a 2000kg single -engine airplane just before takeoff when the thrust of the airplane ia 500N Using the G.U.E.S.S. method asked by jim on November 2, 2009 82. ## stats - URGENT!!!! the following sample observations were randomly selected: x: 2,5,6,8,9,11,15 y: 22,23,16,18,19,13,12 a)calculate the correlation coefficient, r b) determine the regression equation c) determine the value of Y when X=20 asked by skitter on November 30, 2010 83. ## chemistry A certain rifle bullet has a mass of 6.45 g. Calculate the de Broglie wavelength of the bullet traveling at 1817 miles per hour. asked by brianna on November 1, 2013 84. ## physics two lead spheres whose diameters are 20 cm and 2 cm are placed with centres 100 cm apart. Calculate the force of gravitation between them.(density of lead =11500 kg/m^3 asked by Dhananjay on May 15, 2013 85. ## Physics Calculate the thermal energy required to convert 5kg of ice at 0 Celsius to steam at 100 Celsius asked by Lina on February 19, 2016 86. ## Math A sequence {an} is given by a1=root(3), a n+1 = root(3+an). show that {an} is monotonic and bounded, and calculate lim (n->infinity) an, if it exists. Could someone just tell me what answer they get? asked by Hannah on July 11, 2009 87. ## algebra On average a family of four consums 247.2 gallons of water per day. Calculate the quarterly bill for family of four asked by Anonymous on October 24, 2016 88. ## math How do I calculate value of pi upto 200 decimal places ? Please email me the answer to my email address homework@live.in . asked by I want homework help on December 17, 2007 89. ## Chemistry Consider the reaction: 2CO2(g)=2CO(g) + O2(g). A reaction mixture in a 5.0 L flask at a certain temperature. At equilibrium there are 85 g of CO2(g), 1.20 g of CO, and 0.688 g of O2(g). Calculate Kc. asked by Ariel on February 27, 2011 90. ## Business Math Marcus invests$8,000, at 8% interest, compounded annually for 15 years. Calculate the compound interest for his investment.

asked by Jasmine on March 16, 2019
91. ## chemistry

Consider the galvanic cell constructed from the following metals and their corresponding metal ions: E degrees (V) M^3+^ + 3e^-^ ----> M 0.29 N^2+^ + 2e^-^ ----> N 0.61 calculate the value of K for the cell reaction at 25C

asked by eric on July 13, 2012
92. ## calc

a rectangle is inscribed in the upper half of the circle x^2+y^2=a^2 calculate the area of the largest such rectangle. So A=2xy y=sqrt(a^2-x^2)A what do I do from there?

asked by hannah on August 20, 2014
93. ## Math

The surface area of the moon is 37 832 330 km squared. Calculate the side length of a square with the same area.

asked by KimY on October 1, 2011
94. ## ctu math

calculate the interest charge on a \$5.000 balance with the visa student card annual interest rate of 10.8%

asked by simone on August 3, 2013
95. ## chemistry

Calculate the mass percent composition of carbon in each the following carbon compounds. a) C_4H_10 b) C_6H_10 c) CCl_2F_2 d) C_8H_13O_5N

asked by Mely on September 11, 2010
96. ## chemistry

Calculate the mass percent composition of carbon in the following carbon compound. C_8H_13O_5N I got 0.4729 as an answer but it's wrong. Please help me.

asked by Mely on September 11, 2010
97. ## Chemistry

Consider the reaction: 2CO2(g)=2CO(g) + O2(g). A reaction mixture in a 5.0 L flask at a certain temperature. At equilibrium there are 85 g of CO2(g), 1.20 g of CO, and 0.688 g of O2(g). Calculate Kc.

asked by Ariel on February 27, 2011
98. ## stats - URGENT!!!!

the following sample observations were randomly selected: x: 2,5,6,8,9,11,15 y: 22,23,16,18,19,13,12 a)calculate the correlation coefficient, r b) determine the regression equation c) determine the value of Y when X=20

asked by skitter on November 30, 2010
99. ## Math

The angles of depression of two stones one mile apart on the same side of a tower are 30Â° and 45Â° .calculate height of the tower.

asked by Nisha on March 19, 2017
100. ## Chemistry

A block of metal has a width of 3.2 cm, a length of 17.1 cm, and height of 5.8cm . Its mass is 1.5kg . Calculate the density of the metal.

asked by Jenn on September 2, 2013