# ericka

Most popular questions and responses by ericka
1. ## 1 math question

Which is J = 4rb solved for r? a. r = J/4b ** b. r = 4b/J c. r = J - 4b d. r = J/b

2. ## Chemistry

Cyclopropane is converted to propene in a first-order process. The rate constant is 5.4 × 10-2 hr-1. If the initial concentration of cyclopropane is 0.150 M, what will its concentration be after 22.0 hours?

3. ## physics

A 1.5-kg block rests on top of a 7.5kg block. The cord and pulley have negligible mass, and there is no significant friction anywhere. Part a) What force F must be applied to the bottom block so the top block accelerates to the right at 2.9 m/s^2 ? Part b)

4. ## chemistry

A buffer is made by adding 0.300 mol HC2H3O2 and 0.300 mol NaC2H3O2 to enough water to make 1.00 L of solution. The pH of the buffer is 4.74 . Calculate the pH of this solution after 0.020 mol of NaOH is added.

5. ## Science

CH4 + 20 2 --> CO2 + 2H2O How many liters of CO2 would be produced if 32 grams of CH4 are combined with oxygen??? How many grams of H2O would be produced when the 32 grams of CH4 are burned???

6. ## Chemistry

The Ka of hydrazoic acid (HN3) is 1.9 × 10-5 at 25°C. What is the pH of a 0.35-M aqueous solution of HN3?

7. ## physics

Given: latent heat of fusion of water 3.33x10^5 J/kg. A 147 g cube of ice at 0 degress C is dropped into 1.3 kg of water that was originally at 79 degrees C. What is the final temperature of the water after the ice melts.

8. ## Chemistry

The approximate concentration of a hydrochloric acid solution is 0.5M. The exact concentration of this solution is to be determined by the titration with 0.5M solution of sodium hydroxide. A 10.00 ml of HCl solution was transferred by pipet to an

9. ## chemistry

If the concentration of Pb2+ is found to be 2.3 x 10-9 mol/L in a saturated solution of Pb3(PO4)2, what is the Ksp of Pb3(PO4)2 ?

10. ## chemistry

24 mL of 0.39 mol/L acetic acid is titrated with a standardized 0.33 mol/L KOH solution. Calculate the pH of the solution after 17 mL of the KOH solution has been added. Assume the Ka of acetic acid is 1.8 x 10-5.

11. ## math

If someone's height is six feet and is enlarged to 16.8 inches, what is the scale factor?

12. ## chemistry

24 mL of 0.39 mol/L acetic acid is titrated with a standardized 0.33 mol/L KOH solution. Calculate the pH of the solution after 17 mL of the KOH solution has been added. Assume the Ka of acetic acid is 1.8 x 10-5.

13. ## chemistry

24 mL of 0.39 mol/L acetic acid is titrated with a standardized 0.33 mol/L KOH solution. Calculate the pH of the solution after 17 mL of the KOH solution has been added. Assume the Ka of acetic acid is 1.8 x 10-5.

14. ## History

I need help please I am not understanding what my instructor means by "trace the contextof the question across the entire sweep of time, from pre history to c. 1500CE, converting at least 3 separate eras as they are viewed in at least three world culture

15. ## statistics

The data set given below has y^ = 3x - 5 for its regression equation. Find the standard error of estimate. x 3 2 5 8 y 4 1 10 19 A) 1.29 B) 0 C) 2.06 D) 0.17

16. ## physics

Question # 1 : What is the maximum acceleration a car can undergo if the coefficient of static friction between the tires and the ground is 0.82? Question # 2 : A 1.5-kg block rests on top of a 7.5kg block. The cord and pulley have negligible mass, and

17. ## Pre-Calculus

A surveyor measures the distance between buildings X and Y as 200 feet. The angle of elevation from the base of X to the top of Y is 25 degrees. What is the height of building Y?

18. ## Chemistry

A student performed an experiment to determine the molecular weight of a gaseous compound. Using the ideal gas law PV = nRT, and knowing the pressure, temperature, and volume of the vapor, the student calculated the number of moles of gas, n, to be 0.0443

19. ## Math Finite

How many years will it take for \$12,000 to grow to \$15,000 at 5.75% compounded monthly?

20. ## Science

A rectangular brick measures 6cm by 9cm by 20cm and has a mass of 2.563 kilograms. What is the density of the brick in grams per cubic centimeter?

21. ## Math

Flying against the wind, an airplane travels in hours. Flying with the wind, the same plane travels in hours. What is the rate of the plane in still air and what is the rate of the wind? Rate of the plane still in the air= ____km/h Rate of the wind=

22. ## Finite Math

Two balls are drawn from a bag with 4 black balls and 2 white balls. Find th probability distribution got drawing 2 black balls.

24. ## Finite Math

What interest rate, compounded weekly, would you need to be paid in order to grow an \$8000 investment into \$12,000 over a ten year period?

25. ## Finite Math

What interest rate, compounded monthly, would you need to be paid in order to grow a \$2000 investment into \$3500 over a five year period?

26. ## math

3x^2+11x+5=15?

27. ## Chemistry

10g of Sodium Chloride are dissolved in 200ml of H2O. What is the mass percentage of solute in this solution?

28. ## Percy Jackson:Lightning Thief

What is the motif in "Lightning Thief" ?

29. ## fractions

Write the following fraction as a numeral: One piece of pie from a pie that is cut into six parts. Please check: 1/6

30. ## World civilizations

Although most students begin by assuming settled farming life was better than that lived by hunter-gatherers, closer acquaintance with full Paleolithic Hunter-Gatherer life shows us many aspects that could be considered easier than that of very early,

31. ## Biology

A student claims the probability a human sperm will receive all chromatids of maternal origin is 50 %. Explain why she is wrong.

32. ## Biology

A student claims the probability a human sperm will receive all chromatids of maternal origin is 50 %. Explain why she is wrong.

33. ## Math Finite

A two card hand is dealt from a standard deck. What is the probability of drawing at least one face card?

34. ## interior decorating

historically, who influencedthe style and trends of art, architecture, furniture and fashion? a. interior designers b. upper class c. architects d. artists

35. ## Chemistry

I have to list all of the ions of zinc, the thing is, the only ion I could find was Zn^2+. I've googled "ions of zinc" but this was the only one I could find. Are there any others? Thanks.

36. ## geometry

the supplement of an angle is 15 degree less than twice the angle.find the measure of the angle and its supplement.

37. ## geometry

the complement of an angle is 18 degree more than the angle.find the measure of the angle and its complement.

38. ## world history

According to Aristotle , what makes the rich and downtrodden poor rulers?

40. ## Percy Jackson:Lightning Theif

I have to print some pictures about or from the book "Lightning Theif" Does anyone know some pictures? *It cannot be from the movie.

41. ## physcis

What is the maximum acceleration a car can undergo if the coefficient of static friction between the tires and the ground is 0.82?

42. ## physics

Question # 1 : What is the maximum acceleration a car can undergo if the coefficient of static friction between the tires and the ground is 0.82? Question # 2 : A 1.5-kg block rests on top of a 7.5kg block. The cord and pulley have negligible mass, and

43. ## chemistry

The body-centered cubic unit cell of a particular crystalline form of silver is 2.2887A on each side. Calculate the density of this form of silver?

44. ## syllable patterns

how can you tell rather the first vowel in a word has a long or short vowel and how do you divide them

45. ## Chemistry

What is zinc's hardness (high, medium or low) I found the number on a hardness scale, (2) but I have no idea how the scale works, and if this would be considered high.

46. ## HCA 270

Has anyone taken Axia's HCA 270? Need help on Checkpoint: Ration Analysis.

47. ## chemistry

Find the temperature at which the reaction below is spontaneous given this data: Hfo of NH3(g) = - 46 kJ/mol, So of NH3(g) = 192.5 J/mol·K, So of N2(g) = 191.5 J/mol·K, So of H2(g) = 130.6 J/mol·K. N2(g) + 3H2(g) ßà 2NH3(g)

48. ## geometry

find the measure of an angle whose complement and supplement sum up to 126 degrees

49. ## Science

Which pair of states is most likeley to have a similar climate? Oregón arizona? Virginia and North dokota? Ohio and florida? Kansas and missouri?

50. ## Math

What is a lcm

51. ## batlle of seven oaks

how could the battle of seven oaks be seen as a turning point in metis history?

52. ## Algebra

I'm confused regarding the elimination method for 5x - 7y = -16, 2x + 8y = 26

53. ## definition

What is a motif?

54. ## analogies

How do I put this into 2 sentences? up:down heavy:light For example: water:liquid ice:solid Water is a type of liquid. Ice is a type of solid.

55. ## World history

"As his power grows, Charlemagne proves himself a mastermind, next to military and civil government." In what ways?

56. ## physics

What is the pressure inside a 33.1 L container holding 109.1 kg of argon gas at 399 K?

how did mccarthyism affect the lives and political thinkink of th e people in the u s

1. ## Math

posted on December 13, 2018
2. ## Math

hit or miss

posted on December 13, 2018
3. ## Can someone check these answer for me?

TySm Nashi ty to u tht I got a perfect 100% suckers yep anon ur wrong and Nashi is right feel the pain ugly

posted on February 21, 2018
4. ## math fraction

Brain has 3 basketball cards And 5 baseball cards . What fraction of brain's cards are baseball cards?

posted on March 27, 2017
5. ## Algebra

I think the answer is 20

posted on September 27, 2016
6. ## math

Dera mom i love you so much do you love me

posted on February 25, 2015
7. ## Science

All these answers were correct when I used them. I got a 100%! Thank you!

posted on March 31, 2014
8. ## GEOMETRY(SURFACE AREA)

18.63

posted on October 14, 2013
9. ## Percy Jackson:Lightning Thief

Ok. What is a motif, though?

posted on August 27, 2013
10. ## physcis

well noone answered it and so i reposst it. thank you for your responnse but the last message was not needed.

posted on May 7, 2012
11. ## Math

License plates are made using 2 letters followed by 2 digits. How many plates can be made if repetition of letters and digits is allowed?

posted on April 21, 2012
12. ## Substitution Method in Algebra!HELP PLZ!

knfnkasnga \

posted on November 16, 2009
13. ## HCA 270

Sorry, I need help with the whole assignment, CheckPoint: Ratio Analysis. I have no idea what needs to be done to get the answers.

posted on November 7, 2008
14. ## chemistry

Whats wrong with this answer? Ksp = [Pb2+]^3 [PO4]^2 = (2.3E-9)^3 (2/3 * 2.3E-9)^2 = 4/9 * (2.3E-9)^5

posted on April 19, 2008
15. ## chemistry

Ionization equation for Pb3(PO4)2 is Pb3(PO4)2 --> Pb^2+ + 2PO4^3- Ksp = [Pb^2+][2PO4^3-] Ksp = [2.3 x 10-9 mol][4.6 x 10-9 mol] = 1.1 x 10-16 mol I am stuck

posted on April 19, 2008