Most popular questions and responses by Constantine
  1. Chemistry

    Hi, could someone please take a look at the following question? Use the data given below to construct a Born-Haber cycle to determine the lattice energy of CaO. DH°(kJ) Ca(s) → Ca(g) 193 Ca(g) → Ca⁺(g) + e⁻ 590 Ca⁺(g) → Ca2⁺(g) + e⁻ 1010 2

    asked on April 16, 2013
  2. Chemistry - molecular polarity

    Hi Dr. Bob. Could you please take a look at the question below and my work? I'm not sure how to get the correct answer for this question. I would greatly appreciate your help! How many of the following molecules are polar? BrCl3 CS2 SiF4 SO3 A) 1 B) 2 C) 3

    asked on April 18, 2013
  3. Chemistry - radioactivity

    Hello Dr.Bob. Could you check my work please? I'm not sure if I'm right in how I solved this problem. Which of the following nuclides are most likely to decay via beta decay? A) I-131 B) Pb-206 C) F-18 D) Zr-90 E) Ar-40 I know that nuclides undergo beta

    asked on April 19, 2013
  4. Math

    Hello! Could someone please take a look at the problem below and let me know if I made mistakes in simplifying the given equation? I'm quite certain that I did make a mistake somewhere because the original equation and its simplified form give different

    asked on May 31, 2015
  5. Chemistry

    Hi, could someone please take a look at my solution to this problem and let me know if it's correct? I would really appreciate some help. Calculate the theoretical yield for K3[Fe(C2O4)3]*3H2O; 491.258 g/mol Mass of Ferrous Ammonium Sulfate Hexahyrdreate:

    asked on March 25, 2013
  6. Math (Calculus)

    Hello, Could somebody please help me with the following question? It asks to differentiate the function below according to derivate rules of calculus such as the power rule (if f(x)=x^n, then f'(x)=nx^n-1), the product rule (if F(x)=f(x)g(x) then

    asked on August 12, 2015
  7. Chemistry

    Hello, I would greatly appreciate some help with the following problem, as I'm not sure how to proceed. I'm trying to find solubility (Ksp) of Cu(IO3)2 from titration experiment. The following equations were provided: Cu(IO3)2 --> Cu^2+ + 2IO3^- Ksp =

    asked on July 23, 2014
  8. Chemistry - Le Chatelier's Principle

    Hi, I have a question regarding the following chemical equilibrium equation: 2CrO4^2- + 2H3O^+ Cr2O7^2- + 3H2O The question is: how would you manipulate the above equation to produce more Cr2O7^2- ions without adding any Chromium based compounds? I

    asked on March 9, 2014
  9. physics

    A baseball is hit with a speed of 27.0 at an angle of 48.0. It lands on the flat roof of a 12.0 -tall nearby building.If the ball was hit when it was 1.0 above the ground, what horizontal distance does it travel before it lands on the building?

    asked on September 14, 2008
  10. Religion

    WHO DOES THE JVC WORK FOR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    asked on October 15, 2015
  11. Calculus

    Hello, could somebody please help me out with the following question? I would greatly appreciate some assistance. Find all values of x in the interval [0, 2π] that satisfy the equation 3|tanx(x)|=3

    asked on January 21, 2016
  12. Math

    Hi, I have a question regarding simplifying the following expression: (1/x)/((1/3)x^(-2/3)) = 3/3sqrtx The last expression reads three over cube root of x. I don't understand how to get from the expression on the left side of the equal sign to the one on

    asked on July 18, 2016
  13. Calculus

    Hello, Could somebody kindly check my answer for the following question? Find the derivative of the following function: h(x)=3e^(sin(x+2)) h'(x)=3'(e^(sin(x+2))+3(e^(sin(x+2))' h'(x)=0(e^(sin(x+2))+3(e^(sin(x+2))(cos(1)) h'(x)=3cos1(e^(sin(x+2)) I would

    asked on August 18, 2015
  14. Chemistry - electron configuration

    Hello Dr.Bob. Could you please take a look at the following question? I know the correct answer for it, but I'm not sure how to go about solving it. Which ground state electronic configuration will most readily ionize to a 2 + cation? A)

    asked on April 19, 2013
  15. Math (Calculus)

    Hello, I have a difficulty with the following question. The question is asking to find the slope of the tangent at x=3 for this function: f(x)=4x^3/sinx. X is measured in radians. The is the derivative of f(x): f'(x)=(12x^2)(sinx)^-1 +

    asked on August 18, 2015
  1. Math

    Thank you for your help, Scott and Reiny.

    posted on July 18, 2016
  2. Calculus

    Never mind, I understand it now. Thank you for your help, Steve.

    posted on January 21, 2016
  3. Calculus

    Steve, wouldn't I consider only the values for tanx=1 given the interval restriction?

    posted on January 21, 2016
  4. Calculus

    Thank you Steve.

    posted on August 19, 2015
  5. Math (Calculus)

    Hi Steve, thank you for the reply. I think I got it.

    posted on August 18, 2015
  6. Math (Calculus)

    Thank you Steve! I understand it now.

    posted on August 13, 2015
  7. Math

    Yes you are right, there is no such relation. Thank you so much for your help!

    posted on May 31, 2015
  8. Chemistry

    Thank you much Dr. Bob!

    posted on July 24, 2014
  9. Chemistry

    Also, I forgot to mention that the molarity of Na2S2O3 was previously established to be 0.032 M.

    posted on July 23, 2014
  10. Chemistry - Le Chatelier's Principle

    Thank you Dr.Bob. I got it now.

    posted on March 9, 2014
  11. psychology

    The amount of coffee a person drinks is the independent variable because it is the variable that you would be manipulating to find out how that affects alertness which is the dependent variable.

    posted on March 9, 2014
  12. Chemistry - molecular polarity

    Thank you so much. I should've ignored the electronegativity factor.

    posted on April 18, 2013
  13. MATH

    Tom is three times as old as Sam. So when Sam is 20, Tom will be three times as old as that. Multiply 20 by 3 and you will get 60. So when Sam is 20, Tom will be 60.

    posted on April 18, 2013
  14. Chemistry

    Thank you Dr. Bob.

    posted on April 16, 2013
  15. Chemistry

    Thank you Dr. Bob

    posted on March 25, 2013
  16. Chemistry


    posted on November 23, 2010