shana

Popular questions and responses by shana
  1. Chemistry

    need help to balance half reaction in basic solution IO3 to I2

    asked on July 27, 2013
  2. Linear algebra

    Find all complex numbers z satisfying z3 = 27i and give your answer as a comma-separated list of values in the form a+bi.

    asked on March 30, 2017
  3. Chemistry

    Calcium hydroxide, Ca(OH)2, dissolves in water to the extent of 1.78 g per liter. What is the value of Ksp for Ca(OH)2?

    asked on April 22, 2014
  4. chemistry

    Is diphosphorus pentoxide an ionic or a molecular compound? A. Ionic B. Molecular I say B

    asked on November 10, 2012
  5. Linear algebra

    please help me with this question I have no idea how to solve it, thanks Suppose T is a transformation from ℝ2 to ℝ2. Find the matrix A that induces T if T is rotation by 1/6π.

    asked on March 21, 2017
  6. Algebra

    Let L be the line passing through the point P=(1, −1, −5) with direction vector →d=[−2, −4, 3]T, and let T be the plane defined by −x+y−3z = −1. Find the point Q where L and T intersect.

    asked on March 19, 2017
  7. Chemistry

    A 30.00mL sample of 0.150M KOH is titrated with 0.125M HClO4 solution. Calculate the pH after the following volumes of acid have been added: 30.0 mL, 35.0 mL, 36.0 mL, 37.0 mL, 40.0 mL

    asked on November 17, 2011
  8. Chemistry

    The following reaction is reactant-favored at equilibrium at room temperature. COCl2(g) -> CO(g) + Cl2(g) Will raising or lowering the temperature make it product-favored?

    asked on May 1, 2014
  9. chemistry

    When NH3 is treated with oxygen gas, the products obtained are N2(g) and H2O(l). If standard enthalpies of formation at 298 K for NH3(g) and H2O(l) are –46.00 kJ/mol and –286.0 kJ/mol respectively, calculate the enthalpy change of the reaction.

    asked on January 27, 2015
  10. chemistry

    When compared to compound B, compound A has lower melting and boiling points and vaporizes more readily. Is compound A an ionic compound or a molecular compound? A. Ionic B. Molecular I say B

    asked on November 10, 2012
  11. chemistry

    What is usually indicated by an -ite or -ate ending in a chemical formula? A. The compound carries a net ionic charge of zero. B. The compound contains a polyatomic ion. C. The compound is an acid. D. The compound is molecular. I think A

    asked on November 10, 2012
  12. math

    What is one mole of H2O composed of? A. 2 hydrogen atoms and 1 oxygen atom B. 2 × (6.02 × 1023) hydrogen atoms and 6.02 ×1023 oxygen atoms C. 3 atoms of water and 2 oxygen molecules D. one half of a molecule of peroxide I say A

    asked on November 8, 2012
  13. Linear algebra

    please help :( Bob and Doug play a lot of Ping-Pong, but Doug is a much better player, and wins 90% of their games. To make up for this, if Doug wins a game he will spot Bob five points in their next game. If Doug wins again he will spot Bob ten points the

    asked on April 15, 2017
  14. chem

    When NH3 is treated with oxygen gas, the products obtained are N2(g) and H2O(l). If standard enthalpies of formation at 298 K for NH3(g) and H2O(l) are –46.00 kJ/mol and –286.0 kJ/mol respectively, calculate the enthalpy change of the reaction.

    asked on January 27, 2015
  15. math

    What is the percent by mass of hydrogen in C3H8? A. 8.0% B. 18.2% C. 80.0% D. 81.8% I say B

    asked on November 8, 2012
  16. math

    How is percent composition calculated? A. Dividing the mass of each element in the compound by the total mass of the compound and then dividing by 100% B. Dividing the mass of each element in the compound by the total mass of the compound and then

    asked on November 8, 2012
  17. math

    If there is a 75.0 g quantity of carbon present in each 100 g of a carbon and hydrogen compound, what is the percent composition of hydrogen in this compound? A. 25 g B. 25% C. 75 g D. 75% I say B

    asked on November 8, 2012
  18. math

    What is the percent by mass of oxygen in H2O? A. 11.1% O B. 50.0% O C. 88.9% O D. 95.0% O I think C

    asked on November 8, 2012
  19. math

    Solve the following and express the answer in scientific notation:(3.5 x 10^6 / (4.2 x 10^8) A . -8.3 X 10^-3 b. 8.3 X 10^3 c. 8.3 X 10^-2 d. 8.3 X 10^-3 I say A

    asked on November 7, 2012
  20. math

    If the density of 1.77 grams of gold is 19.3 g/mL, what is the volume

    asked on November 7, 2012
  21. Word Problem

    Can someone help me figure out the equation? I am not good at figuring this out. Investing her bonus. Donna invested her $33,000 bonus and received a total of $970 in interest after 1 year. If part of the money returned 4% & the remainder 2.25%, how much

    asked on September 10, 2007
  22. Leadership

    Can leadership be inherited? Do you believe that some people are “born” to be leaders

    asked on March 10, 2020
  23. chemistry

    In Europe, gasoline efficiency is measured in km/L. If your car's gas mileage is 21.0 mi/gal , how many liters of gasoline would you need to buy to complete a 142-km trip in Europe? Use the following conversions: 1km=0.6214mi and 1gal=3.78L.

    asked on September 19, 2019
  24. algebra PLEASE help

    Bob and Doug play a lot of Ping-Pong, but Doug is a much better player, and wins 90% of their games. To make up for this, if Doug wins a game he will spot Bob five points in their next game. If Doug wins again he will spot Bob ten points the next game, and

    asked on April 15, 2017
  25. Linear algebra

    Suppose that the sequence x0, x1, x2... is defined by x0 = 1, x1 = 5, and xk+2 = 3xk+1+10xk for k≥0. Find a general formula for xk.

    asked on April 13, 2017
  26. cell biology

    How can we differentiate MMPs from different proteolytic enzymes

    asked on April 1, 2017
  27. Algebra

    Find the scalar equation for the plane passing through the points P1=(−3, −5, 5), P2=(1, −6, 6), and P3=(0, −9, 4).

    asked on March 19, 2017
  28. Algebra

    can anybody help me with this question please? Let L be the line passing through the point P=(5, −5, 3) with direction vector →d=[1, −3, −2]T. Find the shortest distance d from the point P0=(−4, −1, 4) to L,

    asked on March 1, 2017
  29. Algebra

    I spent hours on this and I still cant figure it out please help me: Let L1 be the line passing through the points Q1=(4, 2, −3) and Q2=(5, 5, −5). Find a value of k so the line L2 passing through the point P1 = P1(3, 7, k) with direction vector

    asked on February 20, 2017
  30. Linear algebra

    Let L1 be the line passing through the points Q1=(−2, 1, 1) and Q2=(−4, 4, 0) and let L2 be the line passing through the point P1=(−6, −6, 0) with direction vector →d=[9, 6, 3]T. Determine whether L1 and L2 intersect. If so, find the point of

    asked on February 20, 2017
  31. algebra

    Plus or minus of 0.05: As measured in standard deviations, how much is a year of learning in school worth on a test? Please answer with a decimal.

    asked on February 27, 2015
  32. statisics

    A major hurricane with wind speeds of 111 per hour or greater. During the last century the mean number of major hurricanes to strike a certain country mainland per year was about 0.45. Find the probability that in a given year exactly one major hurricane

    asked on February 1, 2015
  33. business

    If u carry out a SWOT analysis you should know the " O" stands for a) outliers. B) opportunities c) outlines d) oddities

    asked on August 19, 2014
  34. Chemistry

    How do I find delta S of 2 Na(s) + 2H2O(l) -> 2NaOH(aq) +H2(g)? I tried to find it using this.... ^Srxn= 2S(NaOH) - S(H2) -2S(Na) - 2S(H2O) = 2(48.1)-130.7 - 2(51.21) - 2(69.95) = 96.2 - 130.7 - 102.42 - 139.9 = -279.82 Where did I go wrong??

    asked on May 1, 2014
  35. Chemistry

    Estimate the solubility of calcium fluoride, CaF2+, (a) in moles per liter and (b) in grams per liter of pure water. CaF2+(s) = Ca2+(aq)+2f-(aq)

    asked on April 22, 2014
  36. science

    why it is important to take care of the eyes and go for a regular checkup?

    asked on December 13, 2013
  37. British literature

    How do Falstaff's adventures mirror the main plot in Shakespeare's Henery the 4th

    asked on October 25, 2013
  38. chemistry

    pH = 3.89 calculate concentration of hydronium ion and hydroxide ion in solution.

    asked on July 26, 2013
  39. CURRENT PROCD TERMN CODING

    wHAT IS THE CODING SYSTEM PHYSICIANS USE TO FILE THEIR CLAIMS

    asked on July 15, 2013
  40. math

    Sven is thinking if two numbers. The sum is 12 . The difference is 4. What are the two numbers

    asked on March 7, 2013
  41. math

    estimate the sales tax and final cost of a book that costs $12.99 with a sales tax of 6%

    asked on January 23, 2013
  42. chemistry

    Which of the following consists of positive and negative ions bound together and held in place in a crystalline solid? A. Covalent bonds B. Ionic compounds C. Molecular compounds D. Molecules I say B

    asked on November 10, 2012
  43. chemistry

    Which phase of ionic compounds are good electrical conductors because the ions are free to carry electrical current? A. Solid B. Liquid C. Gas D. Crystalline I say B

    asked on November 10, 2012
  44. chemistry

    Which ion is absorbed by a base in water? A. H3O+ B. OH- C. Neutron D. Transition metal B

    asked on November 10, 2012
  45. math

    When solving for the percent composition of a given compound, the percent of each element in the compound must be found and reported. True false TRUE

    asked on November 9, 2012
  46. math

    127.1 g Cu combines completely with 32.1 g S to form a compound. What is the percent composition of this compound? A. 20% Cu; 80% S B. 50% Cu; 50% S C. 80% Cu; 20% S D. 127% Cu; 32% S I say A

    asked on November 9, 2012
  47. math

    If there is a 75.0 g quantity of carbon present in each 100 g of a carbon and hydrogen compound, what is the percent composition of hydrogen in this compound? A. 25 g B. 25% C. 75 g D. 75% I say B

    asked on November 9, 2012
  48. math

    In order for the percent composition of a compound to be calculated, the molar mass of the compound and the chemical formula must be determined. True False I say true

    asked on November 9, 2012
  49. math

    Convert 1,144 oF to oC A. 617.8 B. 617.8 oC C. −617.8 oC D. −617.8 I say B

    asked on November 7, 2012
  50. math

    To add numbers using scientific notation, multiply the coefficients and then add the exponents. true or false true

    asked on November 7, 2012
  51. math

    Solve the following and express the answer in scientific notation: (5.4 x 10^4) - (2.5 x 10^6) A. -2.45 x 10^6 B. 2.45 x 10^6 C. -2.45 x 10^8 D. -2.44 x 10^2 I say D

    asked on November 7, 2012
  52. math

    Solve the following and express the answer in scientific notation: 10^3 x 10^4 x 10^-2 A. 10^5 B. 10^6 C. 10^7 d. 10^8 I say A

    asked on November 7, 2012
  53. math

    Solve the following and express the answer in scientific notation: (5.3 x 10^4) + (2.2 x 10^3) A. 5.5 x 10^4 B. 7.5 x 10^3 C. 7.5 x 10^7 D. 11.7 x 10^7 I say A

    asked on November 7, 2012
  54. math

    The melting point of helium is -272.2 oC. Express this temperature in kelvins. A. -272 K B. -8.0 K C. 0.8 K D. 545 K I say D.

    asked on November 7, 2012
  55. math

    what is the mass of 1.00 L of ethanol? Ethanol has a density of 0.798 g/ml. (hint: one liter is 10^3 mL.) A. 0.789 g B. 789 g C. 789 L I think C

    asked on November 7, 2012
  56. math

    what is the mass of 12.0 ml of a substance with the density of 0.922 g/cm3? A. 1.11g B. 0.11g C. 11.1 g I think C.

    asked on November 7, 2012
  57. math

    what is the specific gravity of a substance that has a density of 1.59 g/cm3? A. 1.59 g/mL B. 1.59 g C. 1.59 D. 1.59 mL I think B.

    asked on November 7, 2012
  58. math

    if the density of .88 grams of mercury is 13.6 g/ml, what is the volume? A. 0.065 mg B. 0.065 C. 0.065 ml D. 0.065 L I think its C.

    asked on November 7, 2012
  59. math

    If melted butter were poured into a glass of milk and allowed to rest, two distinct layers would be visible. How would these layers appear? A. The melted butter would lie above the layer of milk because butter is less dense than milk. B. The melted butter

    asked on November 7, 2012
  60. math

    Mercury has a density of 13.6 g/cm^3. What is the specific gravity of mercury? A. 13.6 g B. 13.6 cm C. 13.6 cm^3 D. 13.6

    asked on November 7, 2012
  61. math

    In scientific notation, a number is written as the product of a coefficient and the number 10 raised to a power. True False

    asked on November 6, 2012
  62. math

    Solve the following and express the answer in scientific notation: (5.4 × 10^4) × ( 4.5 × 10^8)

    asked on November 6, 2012
  63. english

    The following sentence shows what element of poetry? Her fiery eyes swept away his heart. A. Imagery B. Figure of speech C. Personification D. Simile

    asked on October 16, 2012
  64. english

    What word best describes the Realist's and Modernist's perspective on the world? A. Objective B. Passionate C. Subjective D. Unemotional

    asked on October 16, 2012
  65. english

    Which literary movement consists of honest and open descriptions the setting and characters? I say B. A. American Modernism B. American Realism C. American Romanticism D. American Transcendentalism

    asked on October 16, 2012
  66. MATH

    WHAT IS THE SUM OF ALL THE DISTINCT, POSITIVE PRIME FACTORS OF 1260

    asked on September 11, 2012
  67. Chemistry

    Calculate the theoretical pH at the starting point and at each equivalence point for phosphoric acid, acetic acid, and sulfuric acid. Please show the equilibrium equation, the Ka, and the pH calculation.

    asked on December 12, 2011
  68. Chemistry

    Develop a recipe for 1.00L of pH 4.50 buffer using only 17.4M HC2H3O2 and 3.00M NaOH (and deionized water). Be sure that it can accommodate an addition of at least .50 mol of strong acid or base with a change in pH less than/equal to 1.

    asked on December 12, 2011
  69. Physics

    Find the angle that the vector R = A + B makes with the positive x axis, use counter- clockwise as the positive angular direction, between the limits of −180 degrees and +180 degrees. Answer in units of degrees

    asked on November 18, 2011
  70. statistics

    if a data set has mean 70, and standard deviation 5, is 80 asuspect outliner/

    asked on September 15, 2011
  71. Social Studies

    I am an investor in the Virginia Company. What is a reason of why people should leave England and move to Jamestown. What are the two advantages of living in Virginia? Thank you.

    asked on September 15, 2011
  72. math

    6.8 in fraction notation

    asked on March 13, 2011
  73. Math 11th grade

    How to solve system of equations 5a=5 6b-3c=15 2a+7c=-5

    asked on October 11, 2010
  74. Chemistry 143

    Write three thermochemical equation needed to calculate delta H for the following reaction: 2Mg(s) + O2(g) = 2MgO Include delta h values in kJ for each reaction. Please help!! I don't even know were to start!!

    asked on April 26, 2010
  75. algebra

    Trains a and b are traveling in the same direction on parallel tracks. Train a is traveling at 40 mph and train b is traveling at 50mph. Train a passes a station at 12:15 a.m. If train b passes the same station at 12:27a.m. at what time will train b catch

    asked on April 14, 2010
  76. spanish

    what dose tengo sed puedo ira

    asked on September 10, 2009
  77. 9th grade

    what are energy bar graphs?

    asked on March 13, 2009
  78. math

    My friend found two old watches. He wound them, set them, and started both of them at the same time. He placed the two old watches on one wrist and his new watch on the other wrist. Forty-five minutes later one of the old watches had gained 1 minuate and

    asked on March 5, 2009
  79. math

    a pickup truck has a main tank with a 17 3/4 gallon capacity and an auxiliary tank which holds 15 1/8 gallons. if the truck gets 14 6/10 mpg, how far can the truck trqavel before running out of gas?

    asked on July 28, 2008
  80. math

    Solve the following and express the answer in scientific notation: 10^3 x 10^4. A. 10-^1 B. 10^1 c. 10^6 D. 10^7 I say D

    asked on November 7, 2012
  81. science

    Does flowers store food?

    asked on February 25, 2008
  82. Algebra

    Graph the absolute value inequalities. I just can not get this. Please help! x + 2y ¡Ý 6

    asked on September 10, 2007
  83. College Algebra

    Could you please help me with this problem? We are to graph each compound inequality. x ¡Ý -2y and x - 3y < 6

    asked on September 10, 2007
  84. Juvenile Delinquency

    Compare the adolescence period in the United States with that of other nations. Compare and contrast any ritualistic (rites of passage) behavior used by both Americans and foreign children. Please re-post and include the answer or response you have come up

    asked on November 11, 2006
  1. Matht

    126 is the product of delias height and 7

    posted on December 6, 2019
  2. Linear algebra

    Bob and Doug play a lot of Ping-Pong, but Doug is a much better player, and wins 90% of their games. To make up for this, if Doug wins a game he will spot Bob five points in their next game. If Doug wins again he will spot Bob ten points the next game, and

    posted on April 15, 2017
  3. Algebra

    Thank you so much

    posted on March 19, 2017
  4. chemistry

    i don't know can you please help it is an summative from 32 please

    posted on May 22, 2016
  5. 5th grade Math

    6+10*2

    posted on February 24, 2016
  6. math

    6+10*2 the expression equal 32

    posted on February 24, 2016
  7. math

    3+5*2-210=6

    posted on February 24, 2016
  8. Math

    32.04 x300

    posted on December 10, 2015
  9. Finance

    This is the answer to #5-Capital Co WACC 14.24%

    posted on August 27, 2013
  10. Finance

    THis is the answer to #3 Bell Vineyards 0 $2,000 1 $2,460 2 $2,780 3 $2,986 4 $3,101 5 $3,144 Year 6 to purchase

    posted on August 27, 2013
  11. 6 grade Math

    estimate the sales tax and final cost of a book that costs $12.99 with a sales tax of 6%

    posted on January 23, 2013
  12. math

    think its 13.6 g

    posted on November 7, 2012
  13. Literature (Vocabulary)

    charlatan naïve hoax amicable levity fickle mundane

    posted on February 24, 2012
  14. Social Studies

    Okay, thank you

    posted on September 15, 2011
  15. College Chemistry

    If i combust 1.0kg of octane according to the following unbalanced reaction , how many moles of carbon dioxide should i theoretically produce? 2 C8H18+ 25 O2 -> 16 CO2+ 18 H20

    posted on April 7, 2011
  16. Writing

    31 Myself 32 who 33 they/their 34 they /their

    posted on April 9, 2010