Wednesday

September 2, 2015
Total # Posts: 1,598

**Chemistry Help**

Thank you so much for your help, for the following question i am getting wrong answers answell. for the first one i got 42.7 and the 2nd I got 19.8. Could you help? Thank you for help in advance 4Cr(s) = 3O_2(g) -> 2Cr_2O_3(s) 2Cr(s)+O_2(g)->2SrO(s)
*October 5, 2010*

**Chemistry Help**

I have tried usingg the molecular formula, formulas in the text book but my answers dosent match any of the multiple choice answers, can someone help? For each of the reactions shown, calculate the mass (in grams) of the product formed when 10.7 g of the underlined reactant ...
*October 5, 2010*

**College Chemistry-Please help me**

I need to find the ionic equation of: 3Ba(OH)2(aq)+2H3PO4(aq)->Ba3(PO4)2+6H20(l) I'm totally lost on this question
*October 4, 2010*

**math**

16x^7y^12-10X^5y^8/2x^2y^9 =(16x^7y^12/2x^2y^9)-(10x^5y^8/2x^2y^9) =((16/2)*x^(7-2)*y^(12-9))-((10/2)*x^(5-2)*y^(8-9)) =8x^5y^3-5x^3y^-1 or =(8x^5y^3)-((5x^3)/y)
*October 4, 2010*

**college chemistry**

A chemical engineer determines the mass percent of iron in an ore sample by converting the Fe to Fe^2+ in acid and then titrating the Fe^2+ with MnO4^-. A 1.3510 g sample was dissolved in acid and then titrated with 39.32 mL of 0.03190 M of KMnO4. The balanced equation is: 8H...
*October 4, 2010*

**college chemistry**

I need to find the ionic equation of: 3Ba(OH)2(aq)+2H3PO4(aq)->Ba3(PO4)2+6H20(l)
*October 4, 2010*

**College Chemistry**

What is the oxidation number of (NH4)2SO4
*October 3, 2010*

**College Chemistry**

What is the oxidation number of Cr2(SO4)3
*October 3, 2010*

**College Chemistry**

I balanced the equation: HBr(aq) +NH3(aq)->NH4Br I need to find the ionic equation and the net ionic equation
*October 3, 2010*

**geometry**

mo bisects angle lmn,m angle lmn = 6x-20, m angle lmo= x+32 find m angle nmo but how if i don't know what lmn is From the above info you know lmo=nmo and lmo+nmo=lmn so 2(lmo)=lmn 2(x+32)=6x-20 2x+64=6x-20 2x+84=6x 84=4x 21=x you know lmo=x+32=21+32=53 you also know lmo=...
*October 3, 2010*

**College Chemistry**

Sodium hydroxide is used extensively in acid-base titrations because it is a strong inexpensive base. A sodium hydroxide solution was standardized by titrating 27 mL of 0.1628 M standard hydrochloric acid. The initial buret reading of the sodium hydroxide was 2.44 mL, and the ...
*October 3, 2010*

**college chemistry**

You are given solutions of HCl and NaOH and must determine their concentrations. You use 38 mL of NaOH to titrate 100 mL of HCl and 23.2 mL of NaOH to titrate 50 mL of 0.0782 M H2SO4. Find the unknown concentrations.
*October 3, 2010*

**Math**

[(8*2)- 13]^3+(4-1)^2+4-2*3+|3|-|-6|=? [16-13]^3+(3)^2+4-2*3+3-6 [3]^3+9+4-6+3-6 27+9+4-6+3-6 36+4-6+3-6 40-6+3-6 34+3-6 37-6 31
*October 3, 2010*

**composition and communication**

I need help identifying verb tanses. I have to write 5 sentences about the " role education plays in successful financial planning" using different verb tenses. This is what I have: 1. Education plays an important role in a person’s financial status. (PRESENT ...
*October 3, 2010*

**chemistry**

Determine the oxidation state for the second element in SO3
*September 30, 2010*

**chemistry**

so what wouldit be for Mg3P2? if it has a subscript?
*September 30, 2010*

**chemistry**

Determine the oxidation state for the SECOND element in each of the following: NaF _____ Could you give me the steps to determine the answer
*September 30, 2010*

**geometry**

A thin wire is formed into a rectangle with an area of 24 cm2. If it is reshaped so that the 6 cm side is 2 cm longer, how will the area change?
*September 27, 2010*

**College Chemistry**

How many milliliters of a 0.200M AgNO3 solution are required to preccipitate most of the Cl^- ions from a solution containing 0.855 g of NaCl?
*September 27, 2010*

**College Chemistry**

Pb+NO3+Na2SO4-->?
*September 27, 2010*

**algebra**

5c+5d-8(7c-4d) distribute 5c+5d-56c+32d combine like terms -51c+37d
*September 27, 2010*

**College Chemistry**

The concentration of lead ions (Pb^2+) in a sample of polluted water that also contains nitrate ions (NO3) is determined by adding solid sodium sulfate (Na2SO4) to the sample of the water. Write the net ionic equation for the reaction. Do not forget to indicate the state of ...
*September 27, 2010*

**MATH**

consistent and independent because the answer is (1,4)
*September 26, 2010*

**college chemistry**

How many total moles of ions are released when the following sample dissolves completely in water: 5.15x10^-3 g Ca(NO3)2
*September 26, 2010*

**CHEMISTRY**

THE FOLLOWING SOLUTIONS AREMIXED TOGETHER: 121mL OF 1.54 M AgNO3 AND 45mL OF 1.07 M K2SO4 CALCULATE THE MOLAR CONCENTRATION OF Ag+ IONS IN THE FINAL SOLUTION
*September 26, 2010*

**math factoring**

(a)5x-3x^2 x(5-3x) remove GCF (b)25-x^2 (5+x)(5-x) Diff of 2 squares
*September 26, 2010*

**Chem**

THE FOLLOWING SOLUTIONS AREMIXED TOGETHER: 121mL OF 1.54 M AgNO3 AND 45mL OF 1.07 M K2SO4 CALCULATE THE MOLAR CONCENTRATION OF Ag+ IONS IN THE FINAL SOLUTION
*September 26, 2010*

**chemistry**

A 1.500-g sample of a mixture containing only Cu2O and CuO was treated with hydrogen to prduce 1.252 g pure copper metal. Calculate the percentage composition (by mass) of the mixture.
*September 26, 2010*

**chemistry**

a mixture containing only sodium chloride and potassium chloride has a mass of 4 g. when this sample is dissolved in water and excess silver nitrate is added a white solid forms. after filreation and drying the solid silver chloride has the mass of 8.5904g. calculate the mass ...
*September 25, 2010*

**Chemistry**

A 40.0g sample of an unknow, yellowish-brown, pure metal was heated to 62degrees Celcius and put into a coffee cup calorimeter containing 85.0g of watera at 19.2 degrees Celcius. The water was heated by the hot metal to a temperature of 21.0 degrees Celcius. What is the ...
*September 24, 2010*

**Chemistry**

A 40.0g sample of an unknow, yellowish-brown, pure metal was heated to 62degrees Celcius and put into a coffee cup calorimeter containing 85.0g of watera at 19.2 degrees Celcius. The water was heated by the hot metal to a temperature of 21.0 degrees Celcius. What is the ...
*September 24, 2010*

**chemistry**

For OCTANE, what is the ratio of Carbon atoms to Hydrogen atoms in a molecule? It's specified that Octane undergoes complete combustion to form 8L of Carbon Dioxide & 9L of Water at constant temp and pressure. thanks :)
*September 24, 2010*

**chemistry**

Substances A and B with the same mass and the same initial temperature absorb the same amount of heat energy. The final temperature of A is higher than the final temperature of B. Which substance would have the higher specific heat? Why?
*September 24, 2010*

**algebra**

Solve P=2L+2W for L. L=
*September 24, 2010*

**math**

what is 6 to the second power
*September 21, 2010*

**college physics**

A swimmer is heading straight for the other shore of a river with a velocity of vs=0.7 m/s relative to the water, but is carried away by the current, which has a velocity of vr=0.3 m/s. It takes her 20.3 s to get across. How far downstream does she end up? Can someone please ...
*September 20, 2010*

**college physics**

An airport worker needs to make it across a luggage belt in order to retrieve a stuck suitcase. The belt is moving with 1.6 m/s, and the worker can run with v=1.7 m/s. If he wants to make it straight across the d=2.3 m wide belt, how long will it take for him to reach the ...
*September 20, 2010*

**Math**

BW made c cookies to divide evenly amoung O,TS,SB,and RD and BW himself. Write an algebraic expression that represents the number of cookies each person will receive. I have no clue...sorry those were intitals the problem characters had long names.
*September 20, 2010*

**Physics**

A CD has to rotate under the readout-laser with a constant linear velocity of 1.25 m/s. If the laser is at a position 3.2 cm from the center of the disk, what are the revolutions per minute (rpms) of the disk? ***Can someone please step me through the problem step by step?***
*September 19, 2010*

**chemistry**

in trial one the mass of silver oxide is .5g. The mass of silver metal product is .431 grams. In trial two the silver oxide=.498 and silver metal=.388. Use the conservation of mass to calculate the mass of oxygen that combined with the silver
*September 19, 2010*

**physics**

how do you divide 1.49457 x 10^11 by 3.00 x 10^8? thanks for the help
*September 18, 2010*

**algebra**

solve the equation m-26/5-5m-28/6=2
*September 17, 2010*

**Physics**

The ratio R at which paint can be sprayed from a spray gun may be expressed as R=a.t and R is measured in m3 / s and time is measured in seconds, what are the units of "a"?
*September 17, 2010*

**physics**

Using dimensional analysis, which one of the following equations is dimensionally correct? ( a → m/s2, v → m/s, x → m , t → s)
*September 17, 2010*

**math**

312 yd.
*September 16, 2010*

**Math**

I don't know if I suppose to do LCM or other?I'm going to need help. Beyonce visits her parents every 6 days and Jay-Z vists his parents every 9 days. When will it be the first day they visit there parents on the same day?
*September 16, 2010*

**economics**

What institutions might arise in the free market to help a person decide whether to accept or reject a particular private monetary note?
*September 15, 2010*

**Math**

what is are some free websites that can give me rational and irrational practice?
*September 15, 2010*

**chemistry**

thank you
*September 14, 2010*

**chemistry**

calculate the specific heat (j/g C ) for each of the following: -an 18.5-g sample of tin that absorbs 183 J when its temperature inceases from 35.0 degrees C to 78.6 degrees C
*September 14, 2010*

**chemistry**

how to simplify (x 3-x)/(x-1)?
*September 14, 2010*

**chemistry**

15. On October 21, 1982, the Bureau if the Mint changed the composition of pennies. Instead of an alloy of 95% Cu and 5% Zn by mass, a core of 99.2 Zn and 0.8% Cu with a thin shell of copper was adopted. The overall composition of the new penny was 97.6% Zn and 2.4% Cu by ...
*September 12, 2010*

**physics**

sorry i have about 5 questions on this homework packet that i just can't figure out.... hope you can help me A bowling ball (mass = 7.2 kg, radius = 0.12 m) and a billiard ball (mass = 0.41 kg, radius = 0.028 m) may each be treated as uniform spheres. What is the magnitude...
*September 12, 2010*

**chemistry**

Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes leading to irreversible inactivity of these enzymes. If the amount of mercury in a polluted lake is 0.4 mg Hg/mL, what is the total mass in kilograms of ...
*September 10, 2010*

**chemistry**

that didnt have the right answer i need the steps
*September 8, 2010*

**chemistry**

2.70 g/cm3 to pounds per cubic foot
*September 8, 2010*

**math**

x^4-1/x^3=0
*August 28, 2010*

**math**

cos((sin^-1) 1/2)) sin^-1(sin 7pi/6)
*August 26, 2010*

**Math**

Vehicle A averages 14 miles per gallon of gasoline, and Vehicle B averages 36 miles per gallon of gasoline. At these rates, how many more gallons of gasoline does Vehicle A need than Vehicle B to make a 1,008-mile trip?
*August 26, 2010*

**math**

using point-slope form write an equation, perpendicular to the line y-4=-2(x-3), containing the point (3,4)
*August 25, 2010*

**math**

thank you!
*August 25, 2010*

**math**

12x^2=3x
*August 25, 2010*

**math**

whoops sorry (x-3)(x+3)>0
*August 25, 2010*

**math**

solve of x: (x-3)(x+)>0
*August 25, 2010*

**chemistry**

how would you prepare 1L of a .5M solution of each of the following? Sodium carbonate from the pure solid
*August 25, 2010*

**chemistry**

how would you prepare 1.00 L of 0.50 M solution of NiCl2 from the salt nicl2·6H2O? thanks :)
*August 24, 2010*

**chemistry**

how would you prepare 1.00 L of a .50M solution of H2SO4 from concentrated (18M) sulfric acid?
*August 24, 2010*

**college**

no you already lost me
*August 19, 2010*

**college**

Construct a frequency distribution table for the following scores. Include columns for proportion and percentage in the table. Scores: 5, 7, 8, 4, 7, 9, 6, 6, 5, 3 9, 6, 4, 7, 7, 8, 6, 7, 8, 5
*August 19, 2010*

**Algabra**

Train A travels at 100 mph in the same direction. Train B travels at120 mph on a parallel track. Train A passes a station at 8:25 pm, Train B passes the same station at 8:37 pm. What time will Train B catch Train A?
*August 15, 2010*

**trig**

on the same set of axes sketch the graph of f(x)=sin2x and g(x)=2sin x for x (o,180 degrees)
*August 1, 2010*

**Math**

PQR ~ STU. PQ = 12cm and ST = 9cm. The area of STU is 72 cm². Find the area of PQR.
*July 28, 2010*

**Chemistry**

If 75 g of ice at 0.0 Celsius were added to 1.5 L of water at 75 Celsius, what would the final temperature of the mixture be?
*July 27, 2010*

**MICROECONOMICS**

Suppose that two people, Michelle and James each live alone in an isolated region. They each have the same resources available, and they grow potatoes and raise chickens. If Michelle devotes all her resources to growing potatoes, she can raise 200 pounds of potatoes per year. ...
*July 25, 2010*

**college**

QuadPlex Cinema is the only movie theater in Idaho Falls. The nearest rival movie theater, the Cedar Bluff Twin, is 35 miles away in Pocatello. Thus QuadPlex Cinema possesses a degree of market power. Despite having market power, PuadPlex Cinema is currently suffereing losses...
*July 24, 2010*

**Math(trig)**

Peggy’s Cove Lighthouse, in Nova Scotia, is possibly the most photographed lighthouse in the world. From the observation deck, the angle of depression of a boat is 6º. How far is the boat from the lighthouse, to the nearest metre?
*July 21, 2010*

**Math(trig)**

A 10m flagpole casts an 8m shadow at the same time of day as a building casts a 60m shadow. How tall is the building?
*July 21, 2010*

**trig**

A 10m flagpole casts an 8m shadow at the same time of day as a building casts a 60m shadow. How tall is the building?
*July 21, 2010*

**PHYSIC**

a solid aluminum ingot weighs 89N in air a)what is the volume b)the ingot is suspended from a rope and totally immersed in water. what is the tension in the rope(the apparent weight of the ingot in water)?
*July 20, 2010*

**Calculus**

A 15 ft ladder is leaning against a wall.If the top of the ladder slips down the wall at a rate of 5ft/s, how fast will the foot be moving away from the wall when the top is 9ft above the ground.
*July 17, 2010*

**Calculus**

Both x and y denote functions of t that are related by the given equation. Use this equation and the given derivative information to find the specified derivative. Equation:35x^2+20y^2=1 Given that dx/dt=4, find dy/dt when (x,y)=(1/7sqrt2, 1/5sqrt2)
*July 17, 2010*

**Calculus**

Find f'(x) when f(x)=sin(1/x^3)
*July 17, 2010*

**chemistry**

how many grams of NaOH are contained in 250 mL of a 400 M sodium hydroxide solution
*July 14, 2010*

**history**

the twenty fifth amendment describes the sequence of events that would install the vice president as acting president against the will of the president. outline that sequence of events
*July 9, 2010*

**chemistry**

The vitamin niacin can be isolated from liver, yeast, milk, and whole grain. Which source would be the best for a multivitamin tablet
*July 8, 2010*

**chemistry**

The vitamin niacin can be isolated from liver, yeast, milk, and whole grain. Which source would be the best for a multivitamin tablet
*July 7, 2010*

**ap chemistry**

purpose three models that explain JJ Thomson's findings and evaluate them? What does this mean? are you suppose to make up your own or look to others?
*July 7, 2010*

**pharmacy**

2. On a job interview for a position as a pharmacy technician, the interviewer asks you what a dosage form of medication is. You respond that a dosage form is A. the way a medication is given. B. the use of a medication, either locally or systemically. C. how a medication is ...
*July 5, 2010*

**Pharmacy**

Select the abbreviation which means "make". a. a.c. b. b.i.d. c. M d. F I think it's D but I am not sure.
*July 5, 2010*

**chemistry**

an aspirin tablet contains 5.00X10^2 mg of active ingredient. how many grams of ap of active ingredient does it contain
*July 5, 2010*

**Calculus**

sketch the graph of a function f that is continous everywhere except at x=2, at which point it is continous from the right.Also it is known that f(0)=6 and f(7)=2.
*July 4, 2010*

**kindergarten**

you should make cards with easy words on them and make a picture of the meaning of the card. show it , say it and try to see if your baby can say it to . this helps by giving your baby new words to learn at this young age. i hope this helps you.
*July 3, 2010*

**kindergarten**

you should make cards with easy words on them and make a picture of the meaning of the card. show it , say it and try to see if your baby can say it to . this helps by giving your baby new words to learne at this young age. i hope this helps you.
*July 3, 2010*

**chemistry**

the announced attendance at a football game was 52,806. is this an exact number?
*July 2, 2010*

**chemistry**

you have two beakers one filled to the 100 ml mark with sugar and the other filled to the 100 ml mark with water. you pour the sugar and all the water together in a bigger beaker and stir until all the sugar is compeletely dissovlved. what happens to the mass of the solution?
*July 2, 2010*

**Calculus**

Find the Limit lim as t approaches 1 of (t^3+5t^2-13t+7)/(t^3-3t+2)
*June 30, 2010*

**history**

What were John f Kennedy's key legislation?
*June 30, 2010*

**algebra**

6x-8y=-16 8y-6x=16
*June 29, 2010*

**Biology**

what happens to co2 levels with increasing sugar concentration?
*June 29, 2010*

**10th grade Math**

1.)Explain why ironing boards always remain parallel to the floor and can be adjusted for people of various heights. You may want to consider the following: a.The legs of the board are built so that AD = BD and DE = DF, and ADF and BDE are straight lines as shown. b.Which ...
*June 26, 2010*