Wednesday

July 23, 2014

July 23, 2014

Total # Posts: 316

**Chemistry**

Consider the unbalanced redox reaction: Cr2 O7 2-(aq) + Cu(s) ----> Cr3+(aq) + Cu2+ Balance the equation in acidic solution and determine how much of a 0.850 M K2 Cr2 O7 solution is required to completely dissolve 5.25 g of Cu.

**Calculus **

(i) A 20m chain with a mass-density of 3kg/m (coiled on the ground). How much work is performed lifting the chain so that it is fully extended (and one end touches the ground)? (ii) How much work is performed to lift 1/4 of the chain?

**Chemistry **

Consider the following reaction: CaCO3(s)→CaO(s)+CO2(g). Estimate ΔG∘ for this reaction at each of the following temperatures. (Assume that ΔH∘ and ΔS∘ do not change too much within the given temperature range.) A) 310K and is it spontane...

**Physics**

oh 200 thanks

**Physics**

So what would the magnitude be then?

**Physics**

Bob is pulling a 30kg filing cabinet with a force of 200N , but the filing cabinet refuses to move. The coefficient of static friction between the filing cabinet and the floor is 0.80. What is the magnitude of the friction force on the filing cabinet? Express your answer to tw...

**ALG**

1 r = 1 r1 + 1 r2 for r2

**physics**

A boy with a mass of 50 kg is hanging from a spring with a spring constant of 200 N/m. With what frequency does the boy bounce up and down?

**physics**

The above equation is wrong

**psychology**

what might be some of the things that you could use as test items that would tap into this general form of intelligence that would not be overly affected by cultural matters? If not, why not?

**english**

the blank democratic movement slowly grew stronger as more people began to desire free elections. a:convened b:embarked c:incipient d:generated think its b

**Chemistry**

Hi, I'm a little stuck on this problem: Find the pH of the Hydrochloric acid solution when 5.0 mL of concentrated HCl, with a specific gravity of 1.18 and has 37% (w/w) purity is diluted to 2.0L

**Physics**

A spherical source radiates sound uniformly in all directions. At a distance of 12 m, the sound intensity level is 100 dB. At what distance from the source is the intensity level 40 dB? When I set it up as 100dB/40dB = r^2/(12m)^2, and got x = 18.97 meters, i was told this ans...

**Physics**

A spherical source radiates sound uniformly in all directions. At a distance of 12 m, the sound intensity level is 100 dB. At what distance from the source is the intensity level 40 dB? When I set it up as 100dB/40dB = r^2/(12m)^2, and got x = 18.97 meters, i was told this ans...

**Physics**

A spherical source radiates sound uniformly in all directions. At a distance of 12 m, the sound intensity level is 100 dB. At what distance from the source is the intensity level 40 dB? When I set it up as 100dB/40dB = r^2/(12m)^2, and got x = 18.97 meters, i was told this ans...

**Help **

A result from being multiplied A. Product B. Quotient C. Multiplier D. Expression i say A but i got that wrong so im confused

**vocab**

i mark that and got that wrong i dont understand how thats wrong

**vocab**

A result from being multiplied A. Product B. Quotient C. Multiplier D. Expression a

**history**

2. William Lloyd Garrison’s The Liberator was known for appealing to its readers’ sense of (1 point) A. moral correctness. B. modern convenience. C. economic concern. D. social status. a

**Physics**

while john is traveling along an interstate highway, he notices a 160-mile marker as he passes through town. later john passes another mile marker, 115. a. what is the distance between town and john's current location? b.what is john's current location?

**Physics**

WHat is value of R please? cannot figure out.

**t**

AgCl is dissolved separatel in pure water and in O.O25 (M) NaCl solution.Find the ratio of concentrations of Ag ion in pure water and in the NaCl solution. The solubility product of AgCl is 1.75 to multiply 1O^-1O

**Science**

A 0.2 kg object is released from rest at point A on a track that is one-quarter of a circle with radius 1.6 m, as shown in the figure. It slides down and reaches point B with a speed of 4.8 m/s. Then it slides on a level surface a distance of 3 m until it comes to rest at poin...

**Math**

How do you know when you should re write as a mixed number or simplify; for example. 1 1/2 x 23/9= 3/1 x 23/9= 69/18= what is the way to tell if I should simplify or re write as a mixed number?

**Physics**

A 20 mH inductor in series with a resistance of 55 ohms is connected to a source whose voltage is = 310 V cos 150πt, where t is in seconds. (a) Determine the maximum current in the circuit. (I solved this already, I=5.63A) (b) Determine the maximum and rms voltages across...

**Physics**

A 20 mH inductor in series with a resistance of 55 ohms is connected to a source whose voltage is = 310 V cos 150πt, where t is in seconds. (a) Determine the maximum current in the circuit. (I solved this already, I=5.63A) (b) Determine the maximum and rms voltages across...

**Physics**

A 20 mH inductor in series with a resistance of 55 ohms is connected to a source whose voltage is = 310 V cos 150πt, where t is in seconds. (a) Determine the maximum current in the circuit. (I solved this already, I=5.63A) (b) Determine the maximum and rms voltages across...

**algebra**

A 33-foot-long speaker wire is to be cut into three pieces. One piece is to be 11 feet long. Of the remaining pieces, one must be 2 feet less than 3 times the length of the other. Find the length of the shorter piece

**stats**

Use the given degree of confidence and sample data to construct a confidence interval for the population proportion p. 1) n = 128, x = 93; 90 percent

**stats**

Thirty random students took the final. If the sample mean was 86 and the standard deviation was 9.2 construct a 99 percent confidence interval for the mean score of all

**math**

A tree 15 m tall casts a show of 10m. A nearby building is 30 m tall. What is the length of its shadow?

**algebra**

Is 57/100 greater or less than 2/3?

**Sci**

when a large amount of FeCl3 is dissolved in water, a clear solution is formed at the beginning but eventually a precipitate is formed. Why? Explain with chemical equation.

**English**

oh okay thank you!

**English**

so not a site though. a site would be something that's there permanently, but then what about a chair?

**English**

Is a cardboard box a specific site? A staircase or chair would be a specific site, but what about boxes?

**biology (cell bio)**

Awesome, that makes much more sense. Thank you! My book was rather hard to follow in this section.

**biology (cell bio)**

Can someone explain the Nernst Equation and its purpose, in as simple terms as possible? For some reason it's just not clicking with me. Thanks!

**English **

I am categorizing files by numbers. But I have a couple of files w/o #'s. Then what 1 label would I give these group of files? Ex: # Unknown...

**Question**

I am categorizing files by numbers. But I have a couple of files w/o #'s. Then what 1 label would I give these group of files? Ex: # Unknown...

**Social Studies**

so cars polluting the environment would be a social issue? Also cloning would also be a social issue?

**Social Studies**

what would be an environmental issue that is directly a social issue? animal conservation?

**Social Studies**

Okay, so the same would go for any environmental issues?

**Social Studies **

Is overfishing a social issue?

**math (Urgent, please answer)**

What are some examples of two sets of related data with 10-25 data points each?

**math (urgent,please answer)**

What are some examples of two sets of related data with 10-25 data points each?

**math**

What are some examples of related data that have 10-25 points each?

**math**

a roofer measured the side of a roof to be 4.8 m long . It rises a height of 3.2 m . at what angle does the roof rise to the nearest degree?

**math**

from a point 50 m from the base of a cliff, a surveyor measures the angle of elevation to the top of the cliff as 73.2 degrees. how tall is the cliff to the nearest metre.

**Chemistry **

The solubility of bismuth iodide (BiI3) in water is 10.291 x 10-3 M. Calculate the value of the solubility product. The dissolution products are Bi3+(aq) and I−(aq)

**Chemistry **

A photon interacts with a ground state electron in a hydrogen atom and is absorbed. The electron is ejected from the atom and exhibits a de Broglie wavelength of 0.468×10−10 m. Determine the frequency (in hz) of the interacting photon.

**.345 g anhydrous**

Can you tell me for both.

**.345 g anhydrous**

Can you tell me for both.

**.345 g anhydrous**

What would .345g sample of anhydrous sample do to someone. Could it be harmful.

**Chemistry **

HELP!!! At temperatures above 930 ∘C, PbO reduces PbS to form metallic lead (Pb). The byproduct of the reaction is SO2. Calculate the amount of lead produced (in kg) when a reactor is charged with 487.0 kg of PbS and 750 kg of PbO.

**Chemistry**

A photon interacts with a ground state electron in a hydrogen atom and is absorbed. The electron is ejected from the atom and exhibits a de Broglie wavelength of 0.468×10−10 m. Determine the frequency (in hz) of the interacting photon.

**Chemistry**

HELP!!! Chacho At temperatures above 930 ∘C, PbO reduces PbS to form metallic lead (Pb). The byproduct of the reaction is SO2. Calculate the amount of lead produced (in kg) when a reactor is charged with 487.0 kg of PbS and 750 kg of PbO.

**Chemistry**

0.435

**Chemistry**

for a) no A NO B

**Chemistry**

3.27*10^-7

**math**

a rope was tied to trees at both ends the curve of the rope can be modelled by the equation y=x^2-12x where y is the height and x is the horizontal distance both in feet how far apart are the trees how do you know. show your work

**Physics**

A ship sailing through the St. Lawrence River (fresh water) enters the Atlantic Ocean (salt water). At equilibrium the ship will sit {higher or lower} in the Atlantic Ocean (salt water) compared to the St. Lawrence River (fresh water).

**,Math2**

calculate the cost per barrel if 4000 barrels were extracted from the ground C=9x2-144x+480000 this is a quadratic relation the 2 is a exoponet

**MATH**

if the minimum cost is $608.50 how many barrels are extracted in order to meet the minimum cost. C=9x2-144x+608.50 this is a quadratic relation that 2 is a exponet. please show your work

**Chemistry help please**

You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 359.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of...

**Chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.3 kg m-3. Under these conditions the total surface area of the balloon is 0.33 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of he...

**Chemistry (balloon)**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.3 kg m-3. Under these conditions the total surface area of the balloon is 0.33 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of he...

**Chemistry**

Got the answer thanks anyway

**Chemistry**

Chemical analysis of a silicon crystal reveals gallium at a level of 3.091×10−4 atomic percent. Assuming that the concentration of thermally excited charge carriers from the Si matrix is negligible, what is the density of free charge carriers (free carriers/cm3) in...

**Chemistry**

I still didn't get it right

**Chemistry**

You wish to increase the carbon content of a slab of steel by exposing it to a carburizing atmosphere at elevated temperature. The carbon concentration in the steel before carburization is 359.5 ppm and is initially uniform through the thickness of the steel. The atmosphere of...

**Chemistry**

Chemical analysis of a silicon crystal reveals gallium at a level of 3.091×10−4 atomic percent. Assuming that the concentration of thermally excited charge carriers from the Si matrix is negligible, what is the density of free charge carriers (free carriers/cm3) in...

**math**

Graph each compound inequality. f>3 or f< -2 Which one do I graph? Im confused.....

**math**

Graph each compound inequality. f>3 or f< -2 Which one do I graph? Im confused.....

**Chemistry **

The fictitious compound, arrhenium fluoride ( ), reacts with itself to form a dimer with the formula Ah2F2 . The reaction is second order in AhF. The value of the rate constant is 8.591x10-3 M-1s-1. What is the initial rate of reaction in a reactor filled with AhF to a concent...

**Chemistry**

Oops, I mean the molarity would decrease because moles base / larger quantity in L = a small # therefore decreased molarity. Correct?

**Chemistry**

Or if you didn't correct this error, the molarity of the base would be higher than it should be. Is that correct?

**Chemistry**

How will overshooting the end point of an acid-base titration by adding too much base to KHP affect the calculated molarity of the base? I would think you would need to add more KHP, then more base to bring it to the endpoint. So the molarity calculated should be the same. Is ...

**Chemistry**

You dissolve 20.0 gms of sucrose (sugar) in 200 mL of ethanol 20ºC (density of ethanol at 20ºC is 0.789 gm/ml). What is the mass % of the solute?

**Chemistry**

Concentrated aqueous ammonia contains 1.00 mol NH3 dissolved in 2.50 mol H2O. What is the mole fraction of NH3 in concentrated aqueous ammonia?

**Chemistry**

You dissolve 17.1 gms of sucrose (sugar) in 100 mL of ethanol 20ºC. What is the molarity (M)?

**Chemistry**

I figured it out if it contains the conjugate base of a strong acid

**Chemistry**

When will a salt produce a neutral solution? 1-if it contains the conjugate base of a strong acid 2-if it contains the conjugate base of a weak acid 3-if it contains the conjugate acid of a weak base

**Chemistry**

Is the equation of the chemical reaction that occurs when you blow your breath through boiling water? CO2 + H2O -> H + HCO3

**Chemistry**

How many mg of Ca^2+ are in one mEq? What I did was mg = mEq x mol weight / valence mg = 1 x 40.078/ 2 = 20 mg Is this correct?

**CRT 205**

I am having trouble finding the premise in the article Cyberbullying is Not Worse than Physical Bullying

**Chemistry**

Antacid tab is dissolved in water and a few drops of phenolphthalein is added yielding bright pink solution. 0.2025 M HCl added until pink color disappears. The 0.2147 M NaOH added until it turns light pink for ~30 seconds. mass on antacid tablet = 1.056g initial V 0.2025 M HC...

**Chemistry**

So, Mols NaOH = 0.2264 M NaOH x 0.04936 L NaOH = 0.011175 Mols KHP = grams KHP / molar mass KHP or grams KHP = Mols KHP x molar mass KHP so 0.011175 x 204.22 = 2.2822 grams of KHP Is that correct DBob222?

**Chemistry**

How many grams of KHP (204.22 g/mol) were present in container if 49.36 mL of 0.2264M NaOH were needed to reach the end point of a titration? I'm confused on the formula you would use for this.

**math**

e/7-3=-5 What does e equal? Please show work!

**Physics**

A person consumes 2500 kcal/day while expanding 3500 kcal/day. In a months' time, about how much weight would this person lose if the loss were essentially all from body fat? (Body fat has an energy content of about 4100 kcal per pound).

**biology**

define natural selection

**Math**

ashworth

**Vocab2**

no its not b

**social studies**

mrs.sue can you tell me the answer please I cant find it.

**social studies**

What physical feature is in Africa that is located in the north and seperates it from Europe?

**social studies**

mrs.sue can you tell me the answer please I cant find it.

**math**

w-15=-9 w is a variable, I have to find what it equals

**7th grade science Ms. Sue please check**

Num 5 is A

**SS8R - HELP!**

He controlled some steel mill business that was very popular