# monique

Most popular questions and responses by monique
1. ## bio

The cell membrane is a highly selective barrier that controls the movement of substances in and out of the cell. In fact, polar molecules are unable to go across unless A. they are enclosed in water-filled vesicles. B. they pass through channels in the

2. ## Stoichiometry

Find the limiting reactant for the initial quantities of reactants 2k(s) + Cl2(g)--> 2KCl(s) 1.8 mol K; 1 mol Cl2 I'm lost

3. ## chemistry

a 3.5L sample of a 5.8M NaCl solution is diluted to 55L.What is the molarity of the diluted solution

4. ## Chemistry

For the reaction Ag2S 2Ag + S2 what happens to the equilibrium position if aqueous ammonium sulfide is added A. Shift left B. Shifts right C. Does nothing D. Doubles E. Halves

5. ## Stoichiometry

Consider the reaction between reactants S & O2 2S(s) + 3 O2(g) ==> 2 SO3(g) If a reactant vessel initially contains 5 mol S and 9 mol O2, how many moles of S, O2 and SO3 will be in the reaction vessel once the reactants have reached as much as possible?

6. ## chemistry

Balance the redox reactin in basic. ClO- + Cr(OH)4- --> CrO42- + Cl- H2O + ClO- --> Cl- + 2OH ClO- has a +1 O# and Cl- has a -1 O# how do I balance that. And is what Ive done so far correct? Cr(OH)4- --> CrO42- Im confused on how to balance the oxygen and

7. ## chemistry

an 8.5g ice cube is placed into 255g of water. Calculate the temp change in the water upon the complete melting of the ice. Hint: Determine how much heat is absorbed by the melting ice and then use q = mc^T to calculate the temp change of the 255g of water

8. ## Stoichiometry

For each precipitation reaction, calculate how many grams of the first reactant are necessary to completely react with 17.3 g of the second reactant. 2KI(aq) + Pb(NO3)2(aq)--->PbI2(s) + 2KNO3(aq) Not looking for the answer I really want to know if I did it

9. ## chemistry

If im given mass percent and mass solvent how do I find mass solute and mass solution. example: Mass percent = 3.8% and Mass solvent 45.8 g. Find mass solute and mass solution

Iron is found in Earths crust as several different iron compounds. Calculate the mass (in kg) of each compound that contains 1.0 x 10E3 kg of iron. Fe2O3 Please help step by step

11. ## chemistry

A 45.8mL sample of 5.8M KNO3 solution is diluted to 1.00L. What volume of the diluted solution contains 15.0 g of KNO3.

12. ## Stoichiometry

So I have this question it reads Consider the generic chemical reaction How many moles of B are required to completely react with 2A + 3B ==> 3C 1. 6 mol of A 2. 2 mol of A I won't put them all just guide me in the right direction please

13. ## Statistics #3

The estimate of the population proportion is to be within plus or minus .10, with a 99 percent level of confidence. The best estimate of the population proportion is .45. How large a sample is required?

14. ## chemistry

Describe how you would make 500.0mL of a 0.200M NaOH solution from a 15.0 stock NaOH conentration

15. ## corrected repost chemistry

to what volume should you dilute 125mL of an 8.00M CuCl2 solution so that 50.0mL of the diluted solution contains 5.9g CuCl2 I have a hard time determing the M1V1=M2V2 is

16. ## chemistry

a 10.0mL sample of an unknown H3PO4 solution requirs 112mL of 0.100 M KOH to completely react with the H3PO4. What was the concentrartion of the unknown H3PO4 solution? H3PO4 + 3KOH -----> 3H2O + K3PO4 Ive seen these problems with one volume but not two

17. ## chemistry

Hydrochloric acid is usually purchased in concentrated form with a 37.0% HCL concentration by mass and a density of 1.20g/mL. How much of the concentrated stock solution in milliliters should you use to make 2.5L of 0.500M HCL

18. ## chemistry

A radioactive sample contains 2.45g of an isotope wiht a half life of 3.8 days. How much of the isotope in grams remains after 11.4 days? please explain

19. ## Chemistry

A snorkeler takes a syringe filled with 16 mL of air from the surface, where the pressure is 1.0 ATM, to an unknown depth. The volume of the air in the syringe at this depth is 7.5 mL. What Is the pressure at this depth? If the pressure increases by an

20. ## Chemistry

How many moles of gold atoms do 3.45 x 10^24 gold atoms constitute. This is what I did 3.45 x 10^24 x 1 / 6.022 x 10^23 = 573 am I right

21. ## Chemistry

How many moles of gas must be forced into a 3.5 L ball to give it a gauge pressure of 9.4 psi at 25 degrees C? The gauge pressure is relative to atmospheric pressure. Assume that atmospheric pressure is 14.7 psi so that the total pressure in the ball is

22. ## physics

In a solar water heater, energy from the Sun is gathered by water that circulates through tubes in a rooftop collector. The solar radiation enters the collector through a transparent cover and warms the water in the tubes; this water is pumped into a

23. ## chemistry

an aqueous solution containing 17.5g of an unknown molecular(nonelectrolyte) compound in 100.0g of water has a freezing point of 1.8 degress C. calculate the molar mass of the unknown compound

24. ## chemistry

A glucose solution contains 55.8g of glucose (C6H12O6) in 455g of water. Calculate the freezing poing and boiling point of the solution. (Assume a density of 1.00 g/ml for water. This what I did, I got moles of C6H12O6, 0.89 moles C6H12O6 then I got the

25. ## Chemistry

Write the Lewis structure for each ion Al3+ Mg3+ Se2- N3- My question is why does Se2- get a bracket and 8 dots. And the same for N3-. I hope I'm making sense.

26. ## chemistry

Balance the following redox reaction occurring in acidic solution Cu(s) + NO3-(aq)--> Cu2+(aq) +NO2(g) This is what I have done so far Cu-->Cu2+ + 2e- 2H + NO-3 --> NO2 + H2O Need help please

27. ## chemistry

A wooden boat discovered just south of the Great Pyramid in Egypt had a carbon - 14 content of approximately 50% of that found in living organisms. How old is the boat?

28. ## Statistics

A survey of undergraduate students in the School of Business at Northern University revealed the following regarding the gender and majors of the students: Major Gender Accounting Management Finance Total Male 100 150 50 300 Female 100 50 50 200 Total 200

29. ## U.S History

Which of these statements best describes President Jackson's views on nullification? President Jackson wanted to give the power of government back to the states. President Jackson did not believe a state could legally leave the Union. President Jackson

30. ## chemistry

A KNO3 solution is made using 88.4g of KNO3 and diluting to a total soultion volume of 1.50l. Calculate the molarity and mass percent of the solution. Assume a density of 1.05 g/mL for the solution.

31. ## Algebra1

Population of Mexico has been increasing at annual rate of 1.7% if population was 100,350,000 in year 2000, predict population in 2015. Round to nearest number

32. ## Chemistry

C4H10O(l) + O2(g) --- CO(g) + H2O(g) When I balanced it I got this C4H10O(I) + 4O2(g) --- 4CO(g) + 5H2O Am I correct

33. ## chemistry

A 13.03 g sample contains only ethylene glycol (C2H6O2) and propylene glycol (C3H8O2). When the sample is added to 100.0g of pure water, the resulting solution has a freezing point of -3.5C. What is the percent composition of ethylene glycol and propylene

34. ## Math

Ian gets \$9 for each hour he works and \$10for each day he works. To find out how much he makes in a day, he made the equation y=9x+10x, where x is the number of hours he works. Explain why Ian's equation will not tell him how much he makes in a day.

35. ## chemistry

Balancing Redox Reaction in Basic Solution CN- + MnO-4 --> CNO- + MnO2 H2O + CN- --> CNO- + 2H +2e 3e + 4H + MnO4- --> MnO2 + 2H2O My confusion is with adding the OH- please explain

36. ## Physics

A child riding a bicycle has a total mass of 40kg. The child approaches the top of a hill that is 10m high and 100m long at 5m/s. If the force of friction between the bicycle and the hill is 20N, what is the child's velocity at the bottom of the hill?

37. ## Geometry

A 30-foot cable is suspended between the tops of two 20-foot poles on level ground. The lowest point of the cable is 5 feet above the ground. What is the distance between the two poles?

38. ## algebra

Suppose you have a can of paint that will cover 400 ft squared. A. find the radius of the largest circle you can paint. Round to the nearest tenth of a foot.( hint use the formula A=3.14 times radius squared B. Suppose you have two cans of paint, which

39. ## chemistry

Potash is composed mainly of potassium carbonate, K2CO3. If 1.000g of potash reacts with sulfuric acid to produce 145 mL of carbon dioxide gas at STP, what is the percentage of potassium carbonate in the marble sample? K2CO3 + H2SO4 ==> K2SO4 + H2O + CO2

40. ## Chemistry

A 50g sample of metal was heated to 100 degrees Celsius and then dropped into a beaker containing 50g of water at 25 degrees Celsius. If the specific heat of the metal is .25 cal/g degrees Celsius, what is the final temperature of the water? A. 27 B. 40 C.

41. ## Math

A thin lead apron is used in dental offices to protect patients from harmful X rays. If the sheet measures 75.0 cm by 55.0 cm by 0.10 cm, and the density of lead is 11.3 g/ cm, what is the mass of the apron in grams?

42. ## Chemistry

A thief uses a bag of sand to replace a gold statue that sits on a weight sensitive alarmed pedestal. The bag of sand and the statue have exactly the same volume 1.75 L. Assume that the mass of the bag is negligible. A) calculate the mass. ( density of

43. ## Chemistry

Identify the equation for which Keq= [Cu+]2[S2-]

44. ## chemistry

What is the concentration of the Mg2 ion in solution when [CO3-2] = 0.25M given that the Ksp= 6.82 x 10-6 for the following reaction MgCO3-------->Mg +. CO32- Chemistry - DrBob222, Friday, November 11, 2011 at 5:34pm Ksp = (Mg^2+)(CO3^2-) Substitute 0.25M

45. ## Chemistry

Caffeine a stimulant found in coffee has the mass composition of C, 49.48%, H, 5.19%, N, 28.85%, O 16.48%. The molar mass of caffeine is 194.19g/mol. Find the molecular formula for caffeine.

46. ## Social Studies

Which occur first? egypt and kush develop an interdependent trade relationship egypt conquers kush kush conquers egypt assyrians conquer kush in egypt kush and egypt continue to develop independently of each other

47. ## Chemistry

Consider the chemical reaction C + H2O -----> CO + H2 How many liters of hydrogen gas are formed From the complete reaction of 1.07 mol of C? Assume that the hydrogen gas is collected at a pressure of 1.0 atm and the temperature of 315K So I'm looking for

48. ## biology

Organisms must be able to adapt to a changing external and internal environment. An organism's ability to maintain a stable internal environment is known as homeostasis. How does a cell's membrane help an organism maintain homeostasis? A. Cell membranes

49. ## Chemistry

A 1.250 g sample of copper wire was heated in air and reacted with oxygen to give 1.565 g of copper oxide product. Calculate the empirical formula of the copper oxide. Please help I'm lost. I need step by step Please and thank you

50. ## Chemisrry

If the specific gravity of E85 gasohol is 0.801' what is the mass of 1.00 gallon of th E85 fuel. Given 1 gallon = 3.75 liters

51. ## Chemistry

How many CO2 molecules can be made with 0.500 mol of oxygen atoms?

52. ## Chemistry

Convert a pressure of 23.8 in. Hg into kilopascal. Ok so I looked up kilopascal and it Said 1 Kpa = 1000 pa So I began to set it up like this 23.8 / 29.2 x1000 am I correct Chemistry - DrBob222, Thursday, October 13, 2011 at 1:48pm I don't think that will

53. ## chemistry

calculate the hydronium ion concentration in 0.125M formic acid, HCHO2 Ka= 1.8 x 10-4 can you show me the steps pls

54. ## Chemistry

In this reaction, 4.58 L of O2 were formed at 745mm Hg and 308 K. How many grams of Ag2O decomposed. 2 Ag2O----> 4 Ag + O2 Please help I'm very confused

55. ## Social Studies

Which of the following is a characteristic of a developed nation? A. Low income B.high poverty C.service based economy D.economy based manufacturing

56. ## chemistry

use oxidation states to identify the element that is being oxidized and the element that is being reduced in the redox reaction Sn + 4HNO3 ---> SnO2 + 4NO2 + 2H2O I see that SN is oxidized 0 --> 4+ and book says N is reduced +5 --> +4 I don't see that.

57. ## College physics

The magnetic field at the center of a 0.70-cm-diameter loop is 2.4 mT. What is the current in the loop? A long straight wire carries the same current you found in part a. At what distance from the wire is the magnetic field 2.4 mT?

58. ## Stoichiometry

Find the limiting reactant for the initial quantities of reactants 2k(s) + Cl2(g)--> 2KCl(s) 1.8 mol K; 1 mol Cl2 I'm lost

59. ## chemistry

calculate the pH of a buffer solution containing 0.200M acetic acid, HC2H3O2, plus 0.150M sodium acetate. The dissociation constant for HC2H3O2 is 1.76 x 10-5 I don't think our instructor gave enough notes on these things Im kind of winging it from the

60. ## chemistry

I need help calculating [H3O] from pH and the pOH scale using my calculator. I have a TI-30XIIS

61. ## Algebra

maximize Z = 30x+50y subject to 2x+4y=100 and x+5y=80

62. ## Statistics

The distribution of heights of adult males has a mean of 69 inches and a standard deviation of 4 inches. A random sample of 36 adult males is selected. Find the probability that the average height will be more than 70 inches. a.0.668 b.0.858 c.0.908

63. ## Physics

A construction worker attempts to lift a uniform beam off the floor and raise it to a vertical position. The beam is 2.50m long and weighs 500N. At a certain instant the worker holds the beam momentarily at rest with one end at distance d=1.50m above the

64. ## Math

Ricardo spends 8/9 hour reading the newspaper. He spends 1/4 of the time reading the world news and splits the remaining time equally between the sports news and the comics. How much time does he spend reading the comics?

65. ## chemistry

A rolaids tablet contains calcium carbonate which neutralizes stomach acid. If rolaids tablet neutralizes 42.15 mL of 0.320M hydrochloric acid, how many milligrams of calcium carbonate are in a Rolaids tablet CaCO3 + 2 HCl ------> CaCl2 + H2O + CO2 Pls

66. ## chemistry

how much of a 1.50M solution sodium sulfate solution in milliliters is required to completely precipitate all the barium in 150.0mL of a 0.250 M barium nitrate solution

67. ## College physics

Find the following potential differences. The magnitude of the potential difference DeltaV1 across the resistor of resistance R1 = 15.0 Ohm. The magnitude of the potential difference DeltaV2 across the resistor of resistance R2 = 45.0 Ohm. The magnitude of

68. ## AP Chemistry

An organic compound was synthesized and found to contain only C, H, N, O, and Cl. It was observed that when .150g sample of the compound was burned, it produced .138g of CO2 and .0566g of H2O. All the Nitrogen in a different .200g sample of the compound

69. ## chemistry

a 25.0ml dsmplr og 0.105M HCI was titrated with 31.5ml of NaOH. What is the concentration of the NaOH I got 0.0834M am I correct HCI + NaOH -----> H20 + NaCl 25.0ml HCI x 1L/1000mlx0.105 mol HCI/1L HCI X 1 mol NaOH/ I mol HCI = 0.0834M

70. ## Chemistry

Is it true that Na+ and K+ are always spectator ions in reactions that involve sodium and potassium compounds

71. ## Chemistry

Silver has a density of 10.5 g/cm3 and gold has a density of 19.3 g/cm3. Which would have a greater mass, 5 cm3 of silver or 5 cm3 of gold

72. ## chemistry

how do you figure out how to Balance H2SO4+pb(OH)4=pb(SO4)2=H20

73. ## Finance

A three-year bond has 8.0% coupon rate and face value of \$1000. If the yield to maturity on the bond is 10%, calculate the price of the bond assuming that the bond makes semi-annual coupon interest payments.

74. ## chemistry

Am I headed in the right direction. Sn + MnO4- --> Sn2+ + Mn2+ Sn --> Sn2+ + 2e- 5e + 8H + MnO4- --> Mn2+ + 4H2O If Im right what is the whole number that Im multiplying by

75. ## math

Actually calculate the final amount on \$1000 compounded annually at 6% per year for 4 years.

76. ## Math Statistical #2

Research at the University of Toledo indicates that 50 percent of the students change their major area of study after their first year in a program. A random sample of 100 students in the College of Business revealed that 48 had changed their major area of

77. ## Maths

Write. The following in standard. Form 6120

78. ## Chemistry

Calculate the pH buffer made by combing 50.0 mL of 1.00M ammonia and 50.0mL of ammonium nitrate. Can I use the same formula? If so do I do anything with the mL

79. ## Chemistry

A chemical reaction occurring in a cylinder equipped with a movable piston produces 0.58 mol of a gaseous product. If the cylinder contained 0.11 mol of gas before the reaction and had an initial volume of 2.1 L, what was it's volume after the reaction. Am

80. ## Geography

I am working on my take home quiz questions now...and i am not sure about the answers of the folowing questions...can anyone please help me to check???? THANKS A LOT!!!! (The "*" represents the answer I chose) In the United States, early warning systems

81. ## history

how did the use of bronze give shang warriros on advantage over enemies who did not use bronze?

82. ## Chemistry

What is the concentration of the Mg2 ion in solution when [CO3-2] = 0.25M given that the Ksp= 6.82 x 10-6 for the following reaction MgCO3-------->Mg +. CO32-

83. ## Chemistry

Calculate the empirical formula for the compound 1.245g Ni, 5.381g I Can you help with the steps please

84. ## Physics

Three identical stars of mass M form an equilateral triangle that rotates around the triangle's center as the stars move in a common circle about that center. The triangle has edge length L. What is the speed of the stars?

85. ## math

A company made 4 million in the second quarter this is 1/3 more than it made in the first quarter and 4/5 of what it made in the third quarter how much did the company make in the three quarters combined

86. ## chemistry

please help this equation is driving my crazy. balance the following redox reaction in basic solution. H2O2 + ClO2 --> ClO-2 + O2

87. ## chemistry

An ethylene glycol solution is mad using 58.5g of (C2H6O2) and diluting to a total volume of 500.0 mL. Calculate the freezing and boiling point. Assume a density of 1.09 g/ml for the solution

88. ## Geography

[THESE QUESTIONS ARE NOT THE SAME AS MY PREVIOUS POST) I am working on my take home quiz questions now...and i am not sure about the answers of the folowing questions...can anyone please help me to check???? THANKS A LOT!!!! (The "*" represents the answer

89. ## Geometry

Angle A and Angle B are complementary andgles and the m Angle A = 58 degrees, what is he measure of the supplement of Angle B. This is what I did Angle A and Angle B = 90 degrees, mAngle A = 58 degrees 90 - 58 = 32 degrees 180 - 32 = 148 M angle B

90. ## Chemistry

What is the formula mass for (NH4)3PO4

91. ## Chemistry

Calculate the mass (in kg) of each compound that contains 1.0 x 10E3 kg of iron. Fe2O3 I really can't figure this one out please help step by step

92. ## Physics

A mass of .24 kg is attached to a spring and is set into vibration with a period of .30 s. What is the spring constant of the spring? Answer in units of N/m

93. ## Chemistry

A mixture containing 235 mg of Helium and 325 mg of neon has a total pressure of 453 torr. What is the partial pressure of Helium

94. ## history

what were the contributions of shang dynasties craftspeople?

95. ## Algebra II

Find the difference quotient for the following Rational Function f(x)=5/x using the four steps outlined below. a. find f(x+h) b. find f(x) c. substitute f(x+h) and f(x) into the difference quotient formula. d. simplify

96. ## Math

Moniques credit card charges interest of 20.85% per annum on unpaid balances on her march 12 statement. she had a balance of \$739.65 due by the due date, she made the minimum payment (5% or 10.00, Whichever is greater.) On march 16. She made a purchase of

97. ## chemistry

Silver is electroplated at the cathode of an electrolysis cell by the half reaction Ag+(aq) + e- --> Ag(s) How many moles of electrons are required to electroplate 5.8g of Ag?

98. ## chemistry

Please explain this to me 2I- --> I2 + 2e Cr2O72- ==> Cr3+ 6e + 14H + Cr2O72- ==> 2Cr3+ + 7H20 I don't understand how the left side gets 6 electrons.

99. ## chemistry

Balance the following redox reaction occurring in acidic solution. H+ + Cr --> H2 + Cr3+ H+ --> H2 do I add H+ to this side since H2 = 0? Also what about electrons. Cr -> Cr3+ + 3e- Hope I make sense