Thursday
July 24, 2014

Posts by luke


Total # Posts: 325

Chemistry
Benzene reacts with hot concentrated nitric acid dissolved in sulfuric acid to give chiefly nitrobenzene, C6H5NO2. A by-product is often obtained, which consists of 42.86% C, 2.40% H, and 16.67% N (by mass). The boiling point of a solution of 5.5 g of the by-product in 45 g of...

Chemistry
A saturated solution is made by dissolving 0.252 g of a polypeptide (a substance formed by joining together in a chainlike fashion some number of amino acids) in water to give 1.92 L of solution. The solution has an osmotic pressure of 3.69 torr at 25 °C. What is the appro...

Chemistry
So would you do M=RT/Pi M=(301 x .08205)/.005 4939.41?

Chemistry
A saturated solution is made by dissolving 0.325 g of a polypeptide (a substance formed by joining together in a chainlike fashion some number of amino acids) in water to give 1.37 L of solution. The solution has an osmotic pressure of 4.13 torr at 28 °C. What is the appro...

Chemistry
HOW DO I FIGURE OUT THE MOLECULAR FORMULA FROM THE DATA?

Chemistry
So would the molar mass be 168.2? Empirical be c3h2n1o2?

Chemistry
What is the molar mass of the by-product? Calculate the molecular formula of the by-product. Calculate the empirical formula of the by-product.

Chemistry
Benzene reacts with hot concentrated nitric acid dissolved in sulfuric acid to give chiefly nitrobenzene, C6H5NO2. A by-product is often obtained, which consists of 42.86% C, 2.40% H, and 16.67% N (by mass). The boiling point of a solution of 5.5 g of the by-product in 45 g of...

Chemistry
How do I solve for the y? I get 0.2=23.71g / 24.71+.281 Y. Y But I don't know how to solve

Chemistry
At 21.0 °C, a solution of 23.71 g of a nonvolatile, nonpolar compound in 30.64 g of ethylbromide, C2H5Br, had a vapor pressure of 319.7 torr. The vapor pressure of pure ethyl bromide at this temperature is 400.0 torr. Assuming an ideal solution, what is the molecular mass ...

Chemistry
A solution of acetic acid, CH3COOH, has a concentration of 0.218 M and a density of 1.00 g mL-1. What is the molality of this solution?

Chemistry
Thank you! It was right!!!

Chemistry
A mixture of ammonia and oxygen is prepared by combining 0.250 L of NH3 (measured at 0.700 atm and 20°C) with 0.160 L of O2 (measured at 0.720 atm and 49°C). How many milliliters of N2 (measured at 0.740 atm and 100. °C) could be formed if the following reaction oc...

Chemistry
Methane is formed in landfills by the action of certain bacteria on buried organic matter. If a sample of methane collected from a landfill has a volume of 200. mL at 741 torr and 27.2 °C, how many grams of methane are in the sample? I get the PV=nRT p is 741/760= .975 V t...

Chemistry
Around 514.58?

Chemistry
How many milliliters of O2 are consumed in the complete combustion of a sample of hexane, C6H14, if the reaction produces 325 mL of CO2? Assume all gas volumes are measured at the same temperature and pressure. The reaction is 2C6H14(g) + 19O2(g) -> 12CO2(g) + 14H2O(g)

Chemistry
A mixture of ammonia and oxygen is prepared by combining 0.330 L of NH3 (measured at 0.790 atm and 22°C) with 0.210 L of O2 (measured at 0.820 atm and 48°C). How many milliliters of N2 (measured at 0.740 atm and 100. °C) could be formed if the following reaction oc...

Chemistry
p2=.792atm x 683mL/ 292.15 x 349.15/733mL I got .882 and it says it wrong. Do you know what I done wrong?

Chemistry
When a sample of neon with a volume of 683 mL and a pressure of 0.792 atm was heated from 19.0 to 76.0 °C, its volume became 733 mL. What was its final pressure (in atm)?

Chemistry
so could I solve like n=.975atm *.200L * (300.2/.08205)? 713.45 and thank you for your help!

Chemistry
so .975 x 200mL = n x .08205 x 27.2?

Chemistry
What would my R be? 741torr x 200mL=nR X 27.2

Chemistry
Methane is formed in landfills by the action of certain bacteria on buried organic matter. If a sample of methane collected from a landfill has a volume of 200. mL at 741 torr and 27.2 °C, how many grams of methane are in the sample?

Chemistry
A mixture of N2, O2, and CO2 has a total pressure of 928. torr. In this mixture the partial pressure of N2 is 31.0 cm Hg and the partial pressure of O2 is 4.00 dm Hg. What is the partial pressure of the CO2 (in torr)?

Chemistry
Thank you!

Chemistry
24) It was found that a 20.00 mL portion of a solution of oxalic acid, H2C2O4, requires 6.69 mL of 0.200 M K2Cr2O7 for complete reaction in an acidic solution. In the reaction, the oxidation product is CO2 and the reduction product is Cr3+. How many milliliters of 0.450 M NaOH...

Chemistry
18) Aspirin is a monoprotic acid called acetylsalicylic acid. Its formula is HC9H7O4. A certain pain reliever was analyzed for aspirin by dissolving 0.534 g of it in water and titrating it with 0.0446 M KOH solution. The titration required 26.73 mL of base. What is the percent...

Chemistry
Thank You!!!

Chemistry
12) Naturally occurring argon is composed of 0.3365% of 36Ar (atomic mass, 35.9675 u), 0.0632% of 38Ar (atomic mass, 37.9627 u), and 99.6003% of 40Ar (atomic mass, 39.9624 u). Use these data to calculate the average atomic mass of argon.

Chemistry
13) Mercury is an environmental pollutant because it can be converted by certain bacteria into the very poisonous substance dimethyl mercury, (CH3)2Hg. This compound ends up in the food chain and accumulates in the tissues of aquatic organisms, particularly fish, which renders...

Chemistry
14) A lawn fertilizer is rated as 7.04% nitrogen, meaning 7.04 g of N in 100 g of fertilizer. The nitrogen is present in the form of urea, (NH2)2CO. How many grams of urea are present in 100 g of the fertilizer to supply the rated amount of nitrogen?

Chemistry
How many grams of water could have its temperature raised from 25 ºC (room temperature) to 100 ºC (the boiling point of water) by the amount of energy released in the formation of 4.0 mol of H2 from hydrogen atoms? The bond energy of H2 is 435 kJ/mol. The specific he...

Chemistry
Some time ago, a U.S. citizen traveling in Canada observed that the price of regular gasoline was 0.771 Canadian dollars per liter. The exchange rate at the time was 1.401 Canadian dollars per one U.S. dollar. Calculate the price of the Canadian gasoline in units of U.S. dolla...

Chemistry
Use an enthalpy diagram to calculate the lattice energy of CaCl2 from the following information. Energy needed to vaporize one mole of Ca(s) is 192 kJ. For calcium, the first IE = 589.5 kJ mol-1, the second IE = 1146 kJ mol-1. The electron affinity of Cl is -348 kJ mol-1. The ...

Chemistry
In the spectrum of a specific element, there is a line with a wavelength of 656 nm. Use the Rydberg equation to calculate the value of n for the higher energy Bohr orbit involved in the emission of this light. Assume the value for the lower energy orbit equals 2.

Chemistry
Microwaves are used to heat food in microwave ovens. The microwave radiation is absorbed by moisture in the food. This heats the water, and as the water becomes hot, so does the food. How many photons having a wavelength of 3.00 mm would have to be absorbed by 1.45 g of water ...

Chem
How much methane, in grams, must be burned to release 542 kJ of heat? H=-802kJ

Chem
How much heat (in kilojoules) is liberated by the combustion of 7.01 g of magnesium? Include the sign in your answer. H+-1203kJ

Chemistry
When 4.76 g of a solid mixture composed of NH4Cl and CaCl2 was dissolved in 100.0 mL of water, the temperature of the water rose by 4.73°C. How many grams of each substance was in the mixture?

science
An unsecured astronaut is floating in deep space. He switches on a hand held drill. The drill bit begins rotating clockwise with high angular velocity. Describe what happens to the astronaut- drill system and explain why.

Math problem or trick
if 60% of students in the class were wearing sport shoes and 40% dress shoes, does it mean that everybody in the class were wearing shoes?

Chemistry
comparing and contrasting why is sodium hydrogen carbonate an effective antacid but sodium hydroxide is not?

Physics
A small block on a frictionless surface has a mass of 70 g. It is attached to a massless string passing through a hole in a horizontal surface (see diagram). The block is originally rotating in a circle of radius 45 cm with angular speed 0.80 rad/s. The string is then pulled f...

probability
consider a sequence of independent tosses of a biased coin at times k=0,1,2,…,n. On each toss, the probability of Heads is p, and the probability of Tails is 1−p. A reward of one unit is given at time k, for k∈{1,2,…,n}, if the toss at time k resulted in ...

Biology
We consume carbon in the form of carbohydrates (like the pop you drink or the donuts you eat). We also breath in oxygen. It comes out in the form of carbon dioxide and water.

math
what is the answer to the math pizzazz E-30? What is the title?

Statistics
The probability of Joe is at work is 49%. The probability Joe is at home is 25%. What is the probability Jow is neither at Work nor at home? A) 39% B)74% C)52% D)26% I get the answer at about 38%,but doesn't round to 39%, can anyone help, I'm stuck.

Algebra 2
A card is drawn at random from a full pack of playing cards. It is not put back. A second card is then drawn from the same pack. (a) Find the probability that: (i) both cards are sevens (ii) neither card is a seven (iii) at least one seven is obtained

LA
How does Voltaire give examples in his book Candide that governments need to have both shepherds and butchers

english
Need Help Please..!!! During the Victorian period, there were many social changes and intellectual developments. As a result, a crisis of faith rocked society. How does In Memoriam, A. H. H. by Alfred, Lord Tennyson reflect that crisis? a)Grieving, the speaker first conveys hi...

physics
Suzie (of mass 76 kg) is roller-blading down the sidewalk going 12 miles per hour. She notices a group of workers down the walkway who have unexpectedly blocked her path, and she makes a quick stop in 1.9 seconds. What is Suzie’s average acceleration

Math
Why did Karjam Get a flat tire.

Music
How do you play a dotted quarter note following that an eigth note tied with a quarter note???

English
"In this third circle, write four quotations from The Lightning Thief that relate to the center sketch. Document this quotation properly (The Lightning Thief, Riordan, pg. 84). Does the quotations I put have to be in complete sentence? For example my sketch was riptide fr...

English
Thanks Ms. Sue! :D :D

English
So, like this? "With a double-edged blade" page 153 of The Lightning Thief by Riordan?

English
Like, what are the words in parenthesis? Do I have to use it

English
Document this quotation properly (The Lightning Thief, Riordan, pg. 84).

English
Im doing a project about a book and here is one of my instructions. In this third circle write four quotations from The Lightning Thief that relate to the center sketch. Document this quotation properly (The Lightning Thief, Riordan, pg. 84). What does that mean?

physics
A 4.3 g mass is released from rest at C which has a height of 0.8 m above the base of a loop-the-loop and a radius of 0.31 m. The acceleration of gravity is 9.8 m/s2 . Find the normal force pressing on the track at A, where A is at the same level as the center

Science
How can I draw water powering electricity on my paper? I have to draw a house and ways to power it so I drew the sun, wind mills, solar panels, thick walls, electric poles? Do I draw water near the house?

Science
Ways to have energy in your house without having to use fossil fuels? Use the sun has your light for solar energy Have solar panels wind mills for wind energy thick walls to keep isolation electric poles Any other ways? Or any ways without using fossil fuels you can use for yo...

budgeting
John's gross income is $1,000 per month. Based on an assumption that 25% of his gross income will be withheld, he can expect his disposable (spendable) income to be _______ per month. A. $650 B. $750 C. $850 D. $950 help I am not sure on this I am lost every answer I arriv...

budgeting
A. She should scrap her present budget and start all over again. B. It is clear that Lisa is just one of those people for whom budgeting is impossible. She should give up on the idea. C. She should make adjustments in her food-buying habits and/or look for ways to trim other ...

more statistics
The percent of fat calories that a person in America consumes each day is normally distributed with a mean of 36 and a standard deviation of about 10. Suppose that 16 individuals are randomly chosen for an experiment. Completely describe the distribution of sample means for th...

statistics
PsyDAG, right on thanks

statistics
All deal with a random variable X that follows a normal probability distribution with mean equal to 37 and a standard deviation of 5. Compute P(X < 39) Compute P(X < 29 or X > 41) Compute P(X > 30) Find the 42nd percentile for this distribution.

statistics
All deal with a random variable X that follows a normal probability distribution with mean equal to 37 and a standard deviation of 5. Compute P(X < 39) Compute P(X < 29 or X > 41) Compute P(X > 30) Find the 42nd percentile for this distribution.

Math
Find the Least Common multiple of the two expressions: 24x^2-96 & 18x^2+18x-36

Physics
Two satellites, X and Y, orbit a planet in nearly circular orbits. Satellite X takes 20 days to complete one orbit, while satellite Y takes 160 days. If satellite X has orbital radius 1.0r, what is the orbital radius of satellite Y?

english essay
The second poem I will write about is ‘the conscript’ it was written by Wilfred Gibson in 1917. a law was passed to force men to join up between the ages of 18-41 unless they were ill this poems says what you’re really going to expect from the war if you join up...

Physics
In a common test for cardiac function (the "stress test"), the patient walks on an inclined treadmill (Figure 6-46). Estimate the power required from a 70 kg patient when the treadmill is sloping at an angle of 15° and the velocity is 3.10 km/h.

Physics
A 0.565 kg wood block is firmly attached to a very light horizontal spring (k = 185 N/m) as shown in Fig. 6-40. It is noted that the block-spring system, when compressed 5.0 cm and released, stretches out 2.3 cm beyond the equilibrium position before stopping and turning back....

chemistry
Consider Ba (NO₃)₂ + K₂SO₄ → BaSO₄ + 2KNO₃ (0.10 M) (0.10 M) (10.0 mL) (20.0 mL) Will the K₂SO₄ be sufficient to precipitate all the Ba⁺² ions in the Ba (NO₃)₂? Use Stoichiometry to answer this questi...

Math
Amanda says her quilt has 9 equal parts. Jeremy says it has 3 equal parts. Can they both be correct?

Help math
1 pound is equal to 16 ounces. 4*16=64 you only have 60 so you need 4 more.

Math 6
1 gallon = 4 quarts try it now.

Math
Alexa is choosing a number for her new combination lock. She can use three differents digits from 0 to 9. How many arrangements are there?

food
how much is 2/3rd of a cup of sugar when it is .36 a cup?

Math conversion
I still don't get it.

math
what is the unit rate for 22 gallons of gas to go 682 miles

maths
A mass of 350 kg is lifted by 2 cables connecting at the same point as shown. Determine the tensions in each cable when the system is in equilibrium.Left hand cable is t1 at 40 degree angle and Right hand cable is t2 at 30 degree angle

Math, algebra!! Please help!!!!!!
awsome thanks even though i didnt post this question

Math, algebra!! Please help!!!!!!
good answer

Physics
Consider the conical pendulum, a mass on the end of a string, with the other end of the string fixed to the ceiling. Given the proper push, this pendulum can swing in a circle at an angle q of 25.5 with respect to the vertical, maintaining the same height throughout its motion...

U.s. history
3.) a 6.) a

Chemistry
7 grams of chloride was dissolved in water. 20 ml of lead(II)nitrate was used to completely precipitate all chloride (assume atomic mass of 35g/mol). What is the molarity of the Lead(II) Nitrate solution.

Chemistry
thank you

Chemistry
DrBob222, Is the answer 5M?

Chemistry
7 grams of chloride was dissolved in water. 20 ml of lead(II)nitrate was used to completely precipitate all chloride (assume atomic mass of 35g/mol). What is the molarity of the Lead(II) Nitrate solution.

Physics
While following the directions on a treasure map, a pirate walks 36.6 m north, then turns and walks 6.3 m east. A.) What is the magnitude of the single straight-line displacement that the pirate could have taken to reach the treasure? Answer in units of m. *The answer to A.) i...

biology
Also, i almost forgot it also is 24 carbons, 48 hydrogen, 24 oxygen.

biology
1. 6 Carbon atoms per molecule. 4 Molecules. That's all i know. xD

political science
I do believe that separating the powers among various inter-connected governments is a successful cure because it prevents one branch of government from becoming too powerful over another. I don’t think one branch can completely take over but I think sometimes they find w...

political science
Do you buy James Madison's argument in Federalist 10 and Federalist 51 that separating powers among various inter-connected governments is a successful cure of the "mischief of factions?" Can one faction gain control of enough of our political system to diminish ...

Math
For each of the equations, solve for y in terms of x. 2x-3y=12 5x+2y=7 How do I do this?

Math
43

algebra
I need help with doing this problem... 5x-7(2-4x). Any idea how to do it?

chemistry
If you assume that there is 5% acetic acid in vinegar, how much vinegar should you weigh out so that the endpoint requires 25.0 mL of 0.186 M NaOH?

Physics
A)What is the equation for equivalent resistance for resistors wired in series? What about series wiring makes resistors in series add the way they do? B)What is the equation for capacitors wired in parallel? What about parallel wiring makes capacitors add the way they do? I k...

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