Thursday

January 19, 2017
Total # Posts: 3,381

**chemistry**

1L of a buffer composed of acetic acid and sodium acetate has a pH of 4.3 (total molarity=0.0774) what is the capacity of 200mL of the buffer to survive an addition of HCl without changing by more than 0.4 pH units? i am so lost please help! i know you use the henderson ...

*March 12, 2013*

**chemistry**

I need 1L of a pH 4 buffer with a total molarity of 1. Propose a buffer system and a recipe to achieve this goal. (acetic acid/acetate would probably be a good choice.) help please!

*March 12, 2013*

**chemistry**

1L of a buffer composed of acetic acid and sodium acetate has a pH of 4.3 (total molarity=0.0774) what is the capacity of 200mL of the buffer to survive an addition of HCl without changing by more than 0.4 pH units? i am so lost please help! i know you use the henderson ...

*March 12, 2013*

**Chemistry**

What is the concentration (in M) of an ammonia (NH3) solution if 12.23 grams of ammonia are dissolved to make a 520 mL solution?

*March 11, 2013*

**chemistry**

i got a total concentration of 0.0774M is this correct?

*March 10, 2013*

**chemistry**

for a i got pH=3.97 and for b i got 3.99 for c and d i am stuck.

*March 10, 2013*

**chemistry**

i am suppose to calculate the pH at the new conditions, but i am super lost. also for c and d i think you would have to figure out the moles, but then i do not know what to do from there.

*March 10, 2013*

**chemistry**

1L of a buffer composed of NaHC2O4 and Na2C2O4 has a pHof 4.0 and a total molarity of 1. a). what would the effect on the pH be of adding 1 gram of sodium hydrogen oxalate to this buffer? b). what would be the effect on the pH of adding 1 gram of sodium oxalate to the original...

*March 10, 2013*

**chemistry**

for LiNO3 i found the ionic strength to be .02M for KClO4 i found the ionic strength to be .05M for NaF i found the ionic strength to be .01M i'm stuck on what else to do from here.

*March 10, 2013*

**chemistry**

Find the concentration of Ag+ in a saturated solution of AgBrO3 that also contains 0.02M LiNO3, 0.02M KClO4 and 0.01M NaF.

*March 10, 2013*

**chemistry**

for my answer i got 597559.1682 is this correct??

*March 10, 2013*

**chemistry**

For the reaction 2A(g) + B(aq) + 3C(l)<------> D(s) + 3E(g), the concentrations at equilibrium are found to be: A: 2.3x10^3 Pa B: 1.8x10^-2 M C: 15.8M D: 12.5M E: 5.6x10^4 Torr Find the numerical value of the equilibrium constant that would appear in a conventional table...

*March 10, 2013*

**chemistry**

How do i calculate the pKa??

*March 9, 2013*

**chemistry**

How many grams of Na2CO3 should be mixed with 50.00g of NaHCO3 to produce 2000mL of buffer with pH=10?

*March 9, 2013*

**Calculus**

square root of (12), square root of (12 + square root of (12)), square root of (12+ square root of (12+ square root of (12))) Write a recursion formaula for an(subcription), n greater than or equal to 2.

*March 7, 2013*

**Management for Organizations**

Would someone PLEASE check my answers..THANKS in advance!!! 1. Employee inventories and skills inventories are strategies for ________________________. (D) job design promoting-from-within external recruiting human resource planning 2. Which one of the following choices is not...

*March 7, 2013*

**Math**

A maple tree casts a shadow of 45 ft long. At the same time, a 40-ft-long oak tree casts a shadow which is 60 ft long. Explain how you can use similar triangles to find the height of the tree. Then find the height of the tree.

*March 5, 2013*

**algebra**

the primeter of a rectangle is 24ft. the length is 2 ft longer than the width. Find the dimensions. Write a system of linear equations and solve the resulting system. Let x be the length and y be the width. is the answer for the length 14ft and the width 10 ft?

*March 5, 2013*

**algebra**

thanks so much.

*March 5, 2013*

**algebra**

I am getting lost here. I came up with 8 ft for the length and 4 ft for the width. I hope this is right.

*March 5, 2013*

**algebra**

okay 14ft for length and 10 for the width.

*March 5, 2013*

**algebra**

the primeter of a rectangle is 24ft. the length is 2 ft longer than the width. Find the dimensions. Write a system of linear equations and solve the resulting system. Let x be the length and y be the width. Is the answer for the lenght 16ft and 8ft for the width?

*March 5, 2013*

**algebra**

correction length is 8ft and width is 4 ft.

*March 5, 2013*

**algebra**

okay. I came up with 14ft for the length and 10ft for the width.

*March 5, 2013*

**algebra**

the primeter of a rectangle is 24ft. the length is 2 ft longer than the width. Find the dimensions. Write a system of linear equations and solve the resulting system. Let x be the length and y be the width, write the first equation. 2x+2y=__ write the second equation. x=y+__ ...

*March 5, 2013*

**Math**

You just type in 2.3 x 1.2= ... and it equals to... 2.76. Hope this helped you

*March 5, 2013*

**algebra**

X=10.5 y=13 ...so, you place them in cordinate pairs, like this: (10.5,13) x y Hope this helped.

*March 5, 2013*

**Geometry**

line xy bisect and is perpendicular to ab and cd. ab=6 and ap=5 what is the length of xy

*March 4, 2013*

**Management for Organizations**

Thanks Ms.Sue

*March 2, 2013*

**Management for Organizations**

Please, Would someone check my answers??? Thanks. 7. The organizing function includes all but one of the following activities: (D) A..job design B..increasing departmentalization C..establishing authority relationships D..destabilizing authority relationships 2. Why are small ...

*March 2, 2013*

**Math**

Muna and Rita had 360 seashells. Muna gave 4/7 of her seashells to Rita. In return, Rita gave 2/5 of her total number of seashells to Muna. They then had an equal number of seashells each. How many seashells did each of them have at first?

*March 1, 2013*

**Language Proof and Logic(Philosophy)**

exercise 5.8 write an informal proof of Premises: LeftOf(a,b) | RightOf(a,b) BackOf(a,b) | ~Leftof(a,b) FrontOf(b,a) | ~RightOf(a,b) SameCol(c,a) & SameRow(c,b) conclusion BackOf(a,b) State if you use proof by cases.

*March 1, 2013*

**Chemistry**

Consider the reaction 3Fe(s) + 4H2O(g) ¨ 4H2(g) + Fe3O4(s). If the volume of the container is reduced, 1. more Fe(s) is produced. 2. no change occurs. 3. more H2O(g) is produced. 4. more H2(g) is produced. 5. the equilibrium constant increases.

*February 27, 2013*

**Management for Organizations**

I don't know Ms.Sue I was not tuned in for some reason..lol Thanks and again sorry.

*February 24, 2013*

**Management for Organizations**

I am sorry Ken I am lost in what you are saying are the answers correct or not correct 0_o sorry could you please elaborate. Thanks

*February 24, 2013*

**Management for Organizations**

PLEASE CHECK MY ANSWERS 1. Which of the following is NOT one of Peter Drucker’s contributions to management theory? (D) The analysis of how organizations select managers, how managers act, and how organizations are structured in different units. The understanding of the ...

*February 24, 2013*

**Physics**

Find the mass of water that vaporizes when 3.94 kg of mercury at 248 °C is added to 0.183 kg of water at 83.0 °C.

*February 22, 2013*

**physics**

A container holds 1.3 mol of gas. The total average kinetic energy of the gas molecules in the container is equal to the kinetic energy of a 6.7x10-3 kg bullet with a speed of 830 m/s. What is the Kelvin temperature of the gas?

*February 22, 2013*

**Calculus**

Find the integral of x^2 divided by the square root of (2x-x^2) dx

*February 22, 2013*

**Calculus**

Thank you!

*February 22, 2013*

**Calculus**

Find the integral of x times the square root of (400-100x^2)dx

*February 22, 2013*

**Analytical Chemistry**

for once Dr Bob is right lol. he is usually wrong

*February 22, 2013*

**Physics**

A test tube in a centrifuge is pivoted so that it swings out horizontally as the machine builds up speed. If the bottom of the tube is 180.0 mm from the central spin axis, and if the machine hits 54000 rev/min, what would be the centripetal force exerted on a giant amoeba of ...

*February 22, 2013*

**physics HELP!**

A container holds 1.3 mol of gas. The total average kinetic energy of the gas molecules in the container is equal to the kinetic energy of a 6.7x10-3 kg bullet with a speed of 830 m/s. What is the Kelvin temperature of the gas?

*February 22, 2013*

**Physics**

Find the mass of water that vaporizes when 3.94 kg of mercury at 248 °C is added to 0.183 kg of water at 83.0 °C.

*February 21, 2013*

**Philosophy**

1."Liberals need to understand the global health argument for abortion is deeply offensive. It is like fighting disease by killing everyone who has a disease" This contains: A. euphemism B. dysphemism C. rhetorical definition D. none of the above My answer is C

*February 21, 2013*

**English**

In a research proposal, your sources should not have the potential to answer research questions. True or False.

*February 20, 2013*

**Math 6th grade**

117minutes

*February 19, 2013*

**geometry**

your neighbor is standing at the top of a 14 foot ladder. the base of the ladder is 4 feet from the house. how far off the ground is the neighbor

*February 18, 2013*

**geometry**

your neighbor is standing at the top of a 14 foot ladder. the base is 4 feet from the house. how far off the ground is your neighbor

*February 15, 2013*

**Geometry**

I don't have an advenced calculator so I can't do this question so what does ths equal? Thanks. 11 sin 22 =

*February 15, 2013*

**Geometry**

The top line is 11 long while the base of the right triangle is x and the angle where 11 and x connect is 22 percent.

*February 15, 2013*

**Geometry**

Find the value of x. Round to the nearest tenth. The diagram is not drawn to scale. top 11 bottom x angle between 11 and x is 22 percent.

*February 15, 2013*

**math 5th**

4 by 4 feet

*February 12, 2013*

**calculus**

evaluate the indefinite integral of (5dx)/(xln(7x))

*February 12, 2013*

**calculus**

evaluate the indefinite integral of (9xe^4x^2)dx

*February 12, 2013*

**calculus**

Evaluate the indefinite integral of (5dx)/(xln(6x))

*February 12, 2013*

**calculus**

evaluate the indefinite integral of ((x+4)/(17+8x+x^2))dx

*February 12, 2013*

**calculus**

Evaluate the integral of (((ln(x))^7)/x)dx

*February 12, 2013*

**calculus**

Let f(x)= 2ln(cosx), find f''(x)

*February 12, 2013*

**Chemistry**

Calculate the pH of a water sample from a playa lake in the western US that has the evaporite mineral potassium bicarbonate (KHCO3) at a concentration of 0.009 mol/kg. Assume the water is in equilibrium with the atmosphere (PCO2 = 10-3.4 bar) and the temperature is 25 ̊C...

*February 10, 2013*

**Chemistry**

What would be the pH of a soda water made by saturating pure water with pure CO2 at 1 atm pressure?

*February 10, 2013*

**math**

Find an equation of the line (in slope-intercept form) that passes through the point (7,5) and is perpendicular to the line 7x + 10y - 17 = 0 y=?

*February 8, 2013*

**Physics**

Thanks! blood's density is 1060 kg/m^3 but it worked perfectly! and makes sence

*February 8, 2013*

**Physics**

The blood speed in a normal segment of a horizontal artery is 0.166 m/s. An abnormal segment of the artery is narrowed down by an arteriosclerotic plaque to 1/5 of its normal cross-sectional area. What is the difference in blood pressure between the normal and constricted ...

*February 8, 2013*

**Physics**

A person who weighs 506 N is riding a 94-N mountain bike. Suppose the entire weight of the rider plus bike is supported equally by the two tires. If the gauge pressure in each tire is 6.70 x 105 Pa, what is the area of contact between each tire and the ground?

*February 8, 2013*

**math**

How do you explain to a 3rd grader that 1/2 + 1/8 > 1 whole

*February 7, 2013*

**Finance**

Sheryl’s Shipping had sales last year of $15,000. The cost of goods sold was $7,500, general and administrative expenses were $2,000, interest expenses were $1,500, and depreciation was $2,000. The firm’s tax rate is 30%. a. What are the earnings before interest and ...

*February 4, 2013*

**spanish 102**

¿Se peinaron las chicas antes de dormir? Sí, las chicas se peinaron antes de dormir. ¿Te cepillaste los dientes después de comer? ¿Se maquilla Julia antes de salir a bailar? ¿Se duchan ustedes antes de nadar en la piscina?

*February 3, 2013*

**Algebra**

The power in an electric circuit varies inversely with the resistance. If the power is 1200 watts when the resistance is 12 Ohms, find the power when the resistance is 6 Ohms.

*February 3, 2013*

**literary**

what izs the ouestion

*February 3, 2013*

**Math**

Ann had $198 more than her sister. After their mother gave Ann $20 and her sister $60, Ann had twice as much money as her sister. How much money did Ann have at first.

*February 1, 2013*

**math**

a helicopter blade spins 775 times in 3 minutes. find the rate of the revolutions per second.

*January 31, 2013*

**Chemistry**

How much heat energy, in kilojoules, is required to convert 36.0g of ice at 18.0C to water at 25.0C

*January 30, 2013*

**Physics**

Thanks!! Clears up everything

*January 30, 2013*

**Physics**

Calculate the kinetic energy that the earth has because of (a) its rotation about its own axis and (b) its motion around the sun. Assume that the earth is a uniform sphere and that its path around the sun is circular. For comparison, the total energy used in the United States ...

*January 30, 2013*

**Math**

Two roads intersect at right angles. A water spring is located 65 m from one road and 55 m from the other road. A straight path is to be laid out to pass the spring from one road to the other. Find the least area that can be bounded by the roads and the path. area in m2 = can ...

*January 29, 2013*

**Math**

ok.... so is next step take the first derv of the area Area of rect '= -1/2(4-b^2) + (4-2^2)^1/2

*January 29, 2013*

**Math**

Would it be safe to say that the the diagonal line in the rectangle could equal r = 2. so I could use b^2+ h^2 =r^2 solve for h h= Square root ( r^2 -b^2) Area = b^2 * Square root (r^2-b^2) area = b*(r^2-b^2)^1/2 ....... ????

*January 29, 2013*

**Math**

A mechanical engineering student wishes to inscribe a rectangle in a quarter circle of radius 2.00 cm. Determine the dimensions of the rectangle that will give it the greatest area. length in cm = height in cm = My attempt on find the relationship between the rectangle and the...

*January 29, 2013*

**Math**

Thanks Steve.

*January 29, 2013*

**Math**

The voltage in a circuit is given by the formula V = 16t3 - 79t. Find the values for t for which V is a maximum or a minimum. larger t in seconds = smaller t in seconds = My Answer: V=16t^3-79t V'=48t^2-79 0=48t^2-79 Sq root of 1.645833 = t 1.2829= t V''=96t ...

*January 29, 2013*

**Math Max min problems**

Ok.... great. thank you Steve. I know understand!

*January 29, 2013*

**Math Max min problems**

ok. I understand that you took the value and plugged in for i. But can I ask why...

*January 29, 2013*

**Math Max min problems**

The power P delivered to a load by a current of i amperes through a resistance of 19 ohms, when 110 volts are supplied at one end of the line, is given by the formula P = 110i - 19i2 . Determine the maximum power that can be delivered. maximum power in watts = My Answer: My ...

*January 29, 2013*

**Math**

Oh, sorry I didn't realise that I needed to provide my answer. I just want to check to see if I obtain the correct answer. My answer is: P=110i-19i^2 P'=110-38i 0=110-38i i=2.8947 P"=-38 therefore a max Max Power in watts = 2.8947

*January 29, 2013*

**Math**

The power P delivered to a load by a current of i amperes through a resistance of 19 ohms, when 110 volts are supplied at one end of the line, is given by the formula P = 110i - 19i2 . Determine the maximum power that can be delivered. maximum power in watts =

*January 29, 2013*

**PHYSICS**

Ms. Anderson shoots an arrow straight up into the air. The arrow leaves her bow at 1.2[m] above ground, and reaches a height of 95 feet above ground. It then falls down and penetrates 14 inches into the ground. Find: a) The velocity of the arrow just before reaching the ground...

*January 28, 2013*

**Physics!**

Ms. Anderson shoots an arrow straight up into the air. The arrow leaves her bow at 1.2[m] above ground, and reaches a height of 95 feet above ground. It then falls down and penetrates 14 inches into the ground. Find: a) The velocity of the arrow just before reaching the ground...

*January 28, 2013*

**Physics**

Mr. Anderson shoots an arrow straight up into the air. The arrow leaves her bow at 1.2[m] above ground, and reaches a height of 95 feet above ground. It then falls down and penetrates 14 inches into the ground. Find: a) The velocity of the arrow just before reaching the ground...

*January 28, 2013*

**consumer part3**

Which one of the following items is an example of solfware?

*January 27, 2013*

**Calculus**

I'm not sure what to substitute in this question. Evaluate the integral Square root (tan^-1(x)) / (x^2+1)

*January 27, 2013*

**Physics**

A string on a guitar is supposed to vibrate at 300 Hz, but is measured at 305 Hz. By what percent should the tension in the string be adjusted to correct the tuning?

*January 27, 2013*

**Physics**

A 7.94 nC charge is located 1.75 m from a 4.18 nC point charge. Find the magnitude of the electrostatic force that one charge exerts on the other.

*January 26, 2013*

**math**

a plane flies at 430mph the bearing from Paris to Moscow is 78drgrees and the distance is 1800 mi if the wind is blowing 65mph at 340degrees what heading will take you from Paris to Moscow and how long will it take? include drawing and trip back

*January 23, 2013*

**math**

a boat travels at 16 knots 1st leg: 6hr @ S63W 2nd leg: 4hr @ N10E find time and bearing back to port

*January 23, 2013*

**math**

list a set of at least 12 numbers that has a minium of 28 maximum of 34 median of 30 mode of 29

*January 22, 2013*

**Calculus 2**

I'm confused on how to solve or set up a substitute for the problem. Evaluate the Integral from 1/4 to 1. 1/ sqrt(16t^2 -1) dt

*January 22, 2013*

**English**

10. How does Algernon find out where Jack’s house in the country is located? He eavesdrops on Jack.--Is this correct? He has Lane find out. He steals Jack’s mail. Jack tells him. 11. What is Bunburying? Making up a fake identity to avoid debt collectors. Making up a ...

*January 22, 2013*