Wednesday

August 20, 2014

August 20, 2014

Total # Posts: 325

**Pre Cal**

Two forces with magnitudes of 100 and 50 pounds act on an object at angles of 50° and 160° respectively. Find the direction and magnitude of the resultant force. Round to two decimal places in all intermediate steps and in your final answer.
*August 5, 2014*

**chemistry**

When 3.00 moles of sodium are reacted with large amounts of chlorine gas 145.8 g of sodium chloride are produced determine percentage yield
*July 16, 2014*

**Finacial Accounting.**

I am really struggling with this question and my accounting book is no help at all. A company has $4500 in net sales, $3200 in gross profit, $1300 in ending inventory, and $1800 in beginning inventory. What is the cost of goods sold? Im not looking for the answer, just a ...
*June 29, 2014*

**Chemistry**

A solution buffered at a pH of 5.00 is needed in an experiment. Can we use acetic acid and sodium acetate to make it? If so, how many moles of NaC2H3O2 must be added to a 1.0L of a solution that contains 1.0 mol HC2H3O2 to prepare the buffer. The Ka of acetic acid is 1.8x10^-5...
*June 20, 2014*

**Chemistry**

Determine the concentration of CO32- ions in a 0.18 M H2CO3 solution. Carbonic acid is a diprotic acid whose Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11.
*June 18, 2014*

**Chemisty**

A 0.411 g sample of powdered copper mixed with an inert, soluble additive was fully consumed by 23.4mL of 0.602M nitric acid, producing copper (II) nitrate, water, and nitric oxide. What is the percent copper by mass in the sample? 3Cu + 8HNO3 = 3Cu(NO3)2 +2NO =4H2O
*June 17, 2014*

**Chemistry**

what is the pH solution in which 15 mL of 0.10 M NaOH has been added to 25 mL of 0.10 M HCl
*June 10, 2014*

**Chemistry**

the answer is 0.75mol SO2 but I don't understand where to even begin
*June 9, 2014*

**Chemistry**

Consider the following equilibrium. 2 SO2 (g) + O2 (g) 2 SO3 (g) The equilibrium cannot be established when __________ is/are placed in a 1.0-L container.
*June 9, 2014*

**Chemistry**

what volume (mL) of 0.0962M NaOH is required to neutralize 10.0mL of 0.128M H2SO4? I got 26.6mL
*June 8, 2014*

**algebra**

4x^3-6.68E-7x^2+1.67E-8x-1.04E-10 = 0
*June 8, 2014*

**Math**

4x^3-6.68E-7x^2+1.67E-8x-1.04E-10 = 0
*June 8, 2014*

**Chemistry**

I posted this last night, A 0.500L vessel initially contains 0.0125 mol of H2S2 . Find the equilibrium concentrations of H2 and S2. Kc = 1.67 x 10^-7 2 H2S <--> 2 H2 + S2 I have come up with this equation so far, but I am lost now because I don’t even know if this ...
*June 8, 2014*

**Chemistry**

How many grams of pure H2SO4 can be obtained from 250 grams of iron ore if the ore is 82% FeS2? The reactions involved are given below: 4FeS2 + 11 O2 --> 2 Fe2O3 + 8 SO2 (95% efficient) 2SO2 + O2 --> 2SO3 (90% efficient) SO3 + H2O --> H2SO4 (90% efficient)
*June 7, 2014*

**Chemistry**

I got this equation but now I am lost 1.67x10^-7 = ((4x^2)(x)) / (0.000625-4x^2)
*June 7, 2014*

**Chemistry**

A 0.500L vessel initially contains 0.0125 mol of H2S2 . Find the equilibrium concentrations of H2 and S2. Kc = 1.67 x 10^-7 2 H2S <--> 2 H2 + S2
*June 7, 2014*

**Chemistry **

I posted this question before and the answer is suppose to be 6.8 L but I keep getting 6.12 L dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the ...
*June 3, 2014*

**Chemistry**

I keep getting 6.12 and the answer is suppose to be 6.8
*June 3, 2014*

**Chemistry**

dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the volume of O2 obtained from the reaction of 1.00 mol N2O5 at 45°C and 770 mmHg after 20.0 hours...
*June 3, 2014*

**Chemistry**

Or this balanced equation actually N2O5 = 2 NO2 + 1/2 O2
*June 3, 2014*

**Chemistry**

dinitrogen pentoxide n2o5 decomposes by a first-order decomposition in chloroform solvent to yield NO2 and O2. The rate constant at 45°C is 6.2 x 10^-4 mins^-1. Calculate the volume of O2 obtained from the reaction of 1.00 mol N2O5 at 45°C and 770 mmHg after 20.0 hours...
*June 3, 2014*

**Chemistry**

Nevermind I got the answer myself!
*June 3, 2014*

**Chemistry**

The potassium salt of benzoic acid, potassium benzoate, KC7H5O2, can be made by the action of potassium permanganate on toluene, C7H8. C7H8 + 2 KMnO4 --> 2MnO2 + KOH + H2O If the yield of potassium benzoate cannot be realistically be expected to be more than 71%, what is ...
*June 3, 2014*

**Chemistry **

The first order rate constant is 1.87 x 10^-3 min^-1 at 37°C for reaction of cisplatin. Suppose the concentration of cisplatin in the bloodstream of a patient is 4.73 x 10^-4 mol/L. Calculate the concentration exactly 24 hours later.
*June 3, 2014*

**Chemistry**

How many grams of commercial C2H4O2 (97% pure by mass) must be allowed to react with an excess of PCl3 to produce 50.0g of C2H3OCL if the reaction has a 70% yield? 3C2H4O2 + PCl = 3C2H3OCl + H3PO4
*June 2, 2014*

**Chemistry**

I actually was able to figure it out
*May 31, 2014*

**Chemistry**

0.135m
*May 31, 2014*

**Chemistry**

How many moles of KF are contained in 244 mL of 0.135 m KF solution? The density of the solution is 1.22 g/mL.
*May 31, 2014*

**Chemistry**

At 20°C, an aqueous solution that is 18.0% by mass in ammonium chloride has a density of 1.0512 g/mL What is the molarity of ammonium chloride in the solution?
*May 31, 2014*

**Chemistry**

the solubility of 1-butanol in water is 7.9g per 100g of water. What is the maximum amount of 1-butanol that will dissolve in 5.9g of water
*May 31, 2014*

**Chemistry**

What is the mass percent of an aqueous sodium hydroxide solution in which the molality of NaOH is 6.25m? The density of the solution is 1.2219 g/mL
*May 31, 2014*

**Chemistry**

A sulfuric acid solution that is 65.0% H2SO4 by mass has a density of 1.55 g/mL at 20°C. What is the mass of h2so4 per liter of solution?
*May 31, 2014*

**Chemistry**

Manganese trifluoride, MnF3,can be prepared by the following reaction. 2 MnI2 (s) + 13 F2 (g) ---> 2 MnF3(s) + 4 IF5(l) What is the minimum number of grams of F2 that must be used to react with 12.0 g of MnI2 if the overall yield of MnF3 is no more than 75% of theory?
*May 26, 2014*

**Chemistry**

If 150 mg of aspirin are rinsed with three portions of 10 mL of water at 25 degrees Celsius, how much aspirin is recovered? Solubility of aspirin in water at 25 degrees Celsius is one gram of aspirin per 300 mL of water.
*May 20, 2014*

**Pre-cal**

D) 2log10+log1000-log1
*May 14, 2014*

**Pre-cal**

Simplify: A) log(x+1)+3logx B) 2log4np-3log4p C) 2ln(3x)+ln(5x)-ln6xy D) 22log10+log1000-log1
*May 14, 2014*

**Pre - Cal**

1. Find the vertex of the parabola: 4y^2+4y-16x=0 2. Find an equation of the parabola, opening down, with vertex (-3,1) and solution point (4,-5). 3. The main cables of a suspension bridge are 20 meters above the road at the towers and 4 meters above the road at the center. ...
*May 5, 2014*

**physics**

a rod is having a positive charge and a point charge is placed at a distance 'd' from it making angle 45 degree with one end and 37 degree with the other.calculate field. plz answer its urgent.
*April 10, 2014*

**chemistry **

How many grams of magnesium are required to produce a total of 4.05g of hydrogen
*April 2, 2014*

**Physics**

Prove that tanø is equal to U(k) when the block slides down the incline with a constant speed. (Use symbols, not numbers.)
*March 19, 2014*

**science**

foxes eating mice or leaves growing on trees or rabbits easting clover or fleas living on cat
*February 17, 2014*

**science**

a consumer-producer relationship is best illustrated
*February 17, 2014*

**scince**

as you drive down the highway you may see crows feeding on dead animals. as a result of this nutritional pattern,crows may be classified as
*February 17, 2014*

**chemistry**

solve net ionic equATION Ba(OH)2 + Na2SO4
*February 13, 2014*

**Math**

A swing has a maximum height of 2 m and a minimum height of 0.5 m and it takes 3 seconds to get from the maximum height to the minimum height. Approximate the instantaneous rate of change 1 second into the fall using the difference quotient when h is 0.01. a)-1.3650 b)-0.1973 ...
*November 29, 2013*

**math 5th grade**

59425
*September 17, 2013*

**chemistry**

How would you prepare 500mL of 6.0M NaOH solution using solid NaOH pallets?
*August 8, 2013*

**Informal logic **

Catherine goes to her local movie theater only to see romantic comedies. Since Catherine did not go to the movies yesterday, there is not a romantic comedy playing at her local theater. The reasoning above is flawed because the evidence does not suggest that Catherine goes to ...
*July 14, 2013*

**Informal logic **

All sages provide both wisdom and inspiration. Since Dasha’s speech contained wisdom and greatly inspired her audience, Dasha is a sage. Which one of the following points out the flaw in the argument above? (Points : 1) -Just because Dasha is a sage doesn’t mean that...
*July 14, 2013*

**chemistry**

to what volume should you dilute 0.100L of a 15M NaOH solution to obtain a 1.0M NaOH solution
*July 10, 2013*

**physics**

scientific interpretation of two toy cars having bar magnet on the roof .what happen when close to each other from same and different direction?
*July 2, 2013*

**Math**

Given the altitude of lakes in feet: –12, –9, –14, –39, –49, –49, –18, –43, find the mean, median, mode, and range
*April 22, 2013*

**chemistry**

A reaction produced 0.40 mmol of H in a buffered solution which contained 300ml of 0.06M succinate buffer, pH is 4. What was the pH of the medium after the reaction was completed? The pKa of succinate buffer is 4.21
*April 19, 2013*

**chemistry**

To what volume should 100ml of any weak acid (HA) with a concentration of 0.2M be diluted to double the percentage ionization?
*April 19, 2013*

**Chemistry **

The of hydroxylamine, , is . A buffer solution is prepared by mixing 120 of a 0.34 hydroxylamine solution with 60 of a 0.25 solution.Solve for the PH
*April 19, 2013*

**Chemistry **

What is the pH of a solution prepared by mixing 25.00 mL of 0.10 M CH3CO2H with 25.00 mL of 0.030 M CH3CO2Na? Assume that the volume of the solutions are additive and that a = 1.8 × 10-5 for CH3CO2H.
*April 19, 2013*

**trig**

Find the first two terms a_1 =5 and an=3a _n-1+2
*March 24, 2013*

**Chemistry**

2Al(s)+3Cl2 = 2AlCl3 Limiting Reactant is Cl with 0.329mol. What is the maximum mass of aluminum chloride that can be formed when reacting 30.0g of aluminum with 35.0g of chlorine?
*February 26, 2013*

**Chemistry**

What is the maximum mass of aluminum chloride that can be formed when reacting 30.0g of aluminum with 35.0g of chlorine
*February 26, 2013*

**statistics**

Suppose a random sample of 80 measurements is selected from a population with a mean of 65 and a variance of 300. Select the pair that is the mean and standard error of x.
*February 26, 2013*

**statistics**

Suppose a random sample of 80 measurements is selected from a population with a mean of 65 and a variance of 300. Select the pair that is the mean and standard error of x.
*February 26, 2013*

**math**

133ft.
*January 21, 2013*

**math**

A 6ft man stands next to a 100ft. tall building. the man's shadow is 8ft. long. How long is the building's shadow?
*January 21, 2013*

**math**

how can i find four equivalent expressions example: 50+225
*December 11, 2012*

**chemistry**

Steve, in an attempt to impress his girlfriend, plops 18.2 grams of sodium metal into 500 mL of concentrated phosphoric acid (density = 1.88 g/cm3) in a beaker. The reactants were both initially at 25 oC. The reaction gently produced bubbles of hydrogen and Janet was not ...
*December 9, 2012*

**Chemis**

Steve, in an attempt to impress his girlfriend, plops 18.2 grams of sodium metal into 500 mL of concentrated phosphoric acid (density = 1.88 g/cm3) in a beaker. The reactants were both initially at 25 oC. The reaction gently produced bubbles of hydrogen and Janet was not ...
*December 9, 2012*

**Chemistry**

Strontium metal is responsible for the red color in fireworks. Fireworks manufacturers use strontium carbonate, which can be produced by combining strontium metal, graphite (C), and oxygen gas. The formation of one mole of SrCO3 releases 1.220 x 103 kJ of energy. a) Write a ...
*December 3, 2012*

**Chemistry**

Compute the ƒ´Hrxn for the following: CH3OH „³ H2CO + H2 Carbon is the central atom on both the starting material and the product.
*December 3, 2012*

**Chemistry**

A hungry backpacker needs to boil 150 mL of water to prepare a cup of Ramen Noodles. The filtered river water is at a temperature of 14.2 oC. The pressure is 760 mm Hg and he wants to eat the chicken flavored noodles. How many mL of his liquid butane camping fuel will he use ...
*December 3, 2012*

**math**

A flagpole casts a 32-ft shadow. A boy who is 6 feet tall is standing near the flagpole casting a 16-ft shadow. They form similar triangles. How tall is the flagpole?
*December 1, 2012*

**Chemistry**

Objectives To determine the molecular weight of a volatile liquid. Discussion [This laboratory exercise was adapted from one in Beran and Brady's Laboratory Manual for General Chemistry , John Wiley & Sons, 1982] The Dumas Method for determining the molecular weight of a ...
*November 27, 2012*

**Chemistry**

A Balloon Time® tank holds 15% excess capacity to fill 50 helium balloons measuring 9” or 0.5 ft3 in volume at 1 atm and 22 oC. The gauge pressure of a new tank is 260 psi. What is the volume of a Balloon Time® tank in ft3?
*October 28, 2012*

**math**

limit (x-9)/(sqrt(x))-3 as x-->9
*September 6, 2012*

**Chem**

1.25 x 10^2
*September 6, 2012*

**physics**

An object is moving at constant velocity of 20m/s for 10 seconds. Find the acceleration during the 10 seconds interval?
*August 25, 2012*

**12th Grade world history**

I now know that the answer is A. Large companies tried to be paternalistic to keep workers from rebelling. Thank-you so much for the help! :)
*August 25, 2012*

**12th Grade world history**

With regards to the mining and agriculture industry, in the nineteenth century, which of the following statements is false? A. Large companies tried to be paternalistic to keep workers from rebelling B. Specialization became more common C. Private investment grew D. Reliance ...
*August 25, 2012*

**geometry**

solve for b A,squared + B,squared=c squared given a=3,c=5 help plz
*August 23, 2012*

**Algebra**

Paint Express charges $30 per gallon of paint plus $1.10 per square foot of wall space. Color Creations charges $24 per gallon of paint plus $1.20 per square foot of wall space. Robert estimates he will need four gallons of paint for the rooms he’d like painted. How much ...
*July 18, 2012*

**Advanced Cost Managemement**

Problem 1 - Aunt Ethel's Fancy Cookie Company manufactures and sells three flavors of cookies: macaroon, sugar, and buttercream. The batch size for the cookies is limited to 1,000 cookies based on the size of the ovens and cookie molds owned by the company. Based on ...
*July 15, 2012*

**Math**

A farmer’s harvest in bushels varies directly with the number of acres planted. A. Express in sentence form what this means to the farmer. B.Translate the variation statement into the corresponding variation equation. C. If 8 acres can produce 144 bushels, find the ...
*April 21, 2012*

**Chemistry**

100g of a saturated solution of sodium nitrate at 43°C is cooled quickly with stirring to 10°C. How many grams of the solute will crystallize?
*April 8, 2012*

**GeOmEtRy!!!**

Simplify the expression 5(x+2)- 3(2x-4).
*April 7, 2012*

**math-factoring**

how to factor when there is not a 1 as a coefficient.. for example 2x^2-x-5
*March 14, 2012*

**math**

write two situations that would use the numerical expression 27/9
*March 7, 2012*

**math-matrix**

thanks, wasn't too sure whether I could divide by -23 or not. Found the website, was really helpfull =)
*February 29, 2012*

**math-matrix**

solve using the gauss-jordan method. x-2y+4z=7 -x+3y-z=-1 2x+y=-2 *I get through the first two columbs, but can't get the third one to the one and zero.
*February 29, 2012*

**GeOmEtRy!!!**

The area of a rectangle is (6x^2)^2y^3 and the width is 9xy^2. What is the length of the rectangle?
*February 23, 2012*

**GeOmEtRy!!!**

How many x-intercepts does the graph of y=x^2-4x+4?
*February 23, 2012*

**CHEMISTRY**

1. SF6 2. P4S7 3. SiCl4 4. 5. IF5 6. N4S4 7. Sb2S3 8. Na2CO3 9. 10.
*February 23, 2012*

**GeOmEtRy!!!**

Which of the following expressions is equivalent to (4a^2b)^3(ab)^3? a. 64a^9b^6 b. 12a^7b^6 c. 64a^7b^9 d. 16a^6b^6
*February 23, 2012*

**GeOmEtRy!!!**

a triangle has an area of 35 square inches. The base of the triangle is 4 inches less than twice the height. What is the length of the base of the triangle?
*February 23, 2012*

**GeOmEtRy!!!**

THANKKK YOU!!!!
*February 23, 2012*

**GeOmEtRy!!!**

what are the solutions to the following equation 3x^2+5=80?
*February 23, 2012*

**7th Grade Math**

Hi pepole
*February 23, 2012*

**algebra 1**

The options are: 45t=55t+250 45t+55t=250 55t-45t=250 or 50t=250
*February 9, 2012*

**algebra 1**

If two car are traveling in opposite directions and have average speeds of 45 mph and 55 mph, what equation shows that the cars are 250 miles apart after t hours?
*February 9, 2012*

**6th grade math**

the percent of all adults who take photographs is greater than the percent who play word games but less than the percent who bake. what fraction of all adults might take photographs? Using this table Activity Percent Baking. 17 Barbecuing. 32 Playing chess. 4 Playing word ...
*February 1, 2012*

**geometry**

16 feet
*January 26, 2012*

**GeOmEtRy!!!**

What is the x-intercept of the linear function 6x-10y= -15?
*January 26, 2012*