# Posts by dee

Total # Posts: 927

**Chemistry**

Use the data from this table of thermodynamic properties to calculate the maximum amount of work that can be obtained from the combustion of 1.00 moles of ethane, CH3CH3(g), at 25 °C and standard conditions. I absolutely have no idea what to do, please help me!

*April 30, 2013*

**Chemistry**

Oh I see what I did wrong! Thanks!

*April 30, 2013*

**Chemistry**

i got -1,279.89 and still got it wrong..doing the same calculations just fixing the 468.25 where it belongs

*April 30, 2013*

**Chemistry**

For a particular reaction at 195.1 °C, ΔG = -1488.09 kJ/mol, and ΔS = 288.67 J/(mol·K).? Calculate ΔG for this reaction at -20.0 °C. delta G = delta H - (T*delta S) -1488.09 kJ/mol = (delta H) - ((461.8K)*(+288.67 J/(mol x K))*(1 kJ/1000 J)) -1488...

*April 30, 2013*

**geometry**

Find the weight to the nearest kg, of the cement block. Cement weighs 1700 kg/m3. 12cm x 10cm and 40cm x 20 cm x 20cm.

*April 20, 2013*

**statistics**

It takes approximately 15 minutes to code one record. How many personnel hours would be needed to code 1,424 discharges for the month?

*April 15, 2013*

**Chemistry**

So i got Ka = X^2/(0.184-x) not sure what to do next.

*April 11, 2013*

**Chemistry**

The Ka of a monoprotic weak acid is 4.47 × 10-3. What is the percent ionization of a 0.184 M solution of this acid?

*April 11, 2013*

**physics**

A solid steel cylinder is standing (on one of its ends) vertically on the floor. The length of the cylinder is 3.4 m and its radius is 58 cm. When an object is placed on top of the cylinder, the cylinder compresses by an amount of 5.9 10-7 m. What is the weight of the object?

*April 3, 2013*

**physics**

A copper cube, 0.31 m on a side, is subjected to two shearing forces, each which has a magnitude F = 6.40 106 N (see the drawing). Find the angle θ (in degrees), which is one measure of how the shape of the block has been altered by shear deformation.

*April 3, 2013*

**Cal**

Find the critical number of the function. g(t) = | 4t - 9 |

*April 3, 2013*

**Chemistry**

At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.100 M and [NO]=0.500 M. The balanced chemical equation is N2+O2<--->2NO. If more NO is added, bringing its concentration to 0.800 M, what will the final concentration of NO be after ...

*April 2, 2013*

**Chemistry**

If a 4.30 M sample of A is heated to 500 K, what is the concentration of B at equilibrium? A(aq) --><--- 2B(aq) Kc=8.54 x 10^-6 at 500K ---><--- = equilibrium

*April 2, 2013*

**Chemistry**

At a certain temperature, the Kp for the decomposition of H2S is 0.755 H2S (g) <-- --> H2 (g) + S (g) Initially, only H2S is present at a pressue of 0.201 atm in a closed container. what is the total pressure in the container at equilibrium?

*April 2, 2013*

**Chemistry**

Phosphorus pentachloride decomposes according to the chemical equation PCl5(g) ⇌ PCl3(g) + Cl2(g) A 0.304 mol sample of PCl5(g) is injected into an empty 4.75 L reaction vessel held at 250 °C. Calculate the concentrations of PCl5(g) and PCl3(g) at equilibrium.

*April 2, 2013*

**Chemistry**

At a certain temperature, the equilibrium constant for the following chemical equation is 2.00. At this temperature, calculate the number of moles of NO2(g) that must be added to 2.64 mol of SO2(g) in order to form 1.10 mol of SO3(g) at equilibrium. SO2(g) + NO2(g) <--->...

*April 2, 2013*

**Physics**

The drawing shows a sulfur dioxide molecule. It consists of two oxygen atoms and a sulfur atom. A sulfur atom is twice as massive as an oxygen atom. Using this information and the data provided in the drawing, find (a) the x coordinate and (b) the y coordinate of the center of...

*April 1, 2013*

**Cal**

lim_(x->0^+)(tan(9x))^x

*March 27, 2013*

**chemistry**

How many grams are in 4.00mol of sodium chloride (\rm NaCl)

*March 24, 2013*

**Science**

How does the number of neutrons in a stable nucleus compare with the number of protons?

*March 22, 2013*

**Science**

If the half-life of a radionuclide is 1 month, is a sample of it completely decayed after 2 months?

*March 22, 2013*

**physical science**

What physical quantities are governed by the quantum numbers of an atomic electron?.

*March 22, 2013*

**Physics**

A half-atwood machine is constructed, as shown in the drawing below. The table is NOT frictionless, M1 is 50 grams, and M2 is 30 grams. Mass M2 descends 32 cm in 18 seconds. Find the tension in the wire.

*March 21, 2013*

**phical science**

Photons and neutrinos have neither charge nor mass. What are the differences between them?

*March 18, 2013*

**Cal**

Differentiate the function. f(x) = sin(x) ln(2x)

*March 14, 2013*

**math**

nevermind, all figured out. thanks!

*March 11, 2013*

**math**

oops, yes carrot cakes...typed too fast. still don't understand, can you explain it better for me please?

*March 11, 2013*

**math**

castor brought 6 3/4 carat cakes to share with 26 students. did castor bring enough for each student to have 1/4 of cake?

*March 11, 2013*

**Cal 1**

Use Newton's method with the specified initial approximation x1 to find x3, the third approximation to the root of the given equation. (Round your answer to four decimal places.) 1/3x^3 + 1/2x^2 + 1 = 0, x_1 = −3

*March 7, 2013*

**Cal 1**

Verify the given linear approximation at a = 0. Then determine the values of x for which the linear approximation is accurate to within 0.1. (Enter your answer using interval notation. Round your answer to two decimal places.) tan x ≈ x

*March 7, 2013*

**Cal 1**

Verify the given linear approximation at a = 0. Then determine the values of x for which the linear approximation is accurate to within 0.1. (Enter your answer using interval notation. Round your answers to three decimal places.) (1 + 2x)^1/4 ≈ 1 + 1/2x

*March 7, 2013*

**Cal 1**

Find the linearization L(x) of the function at a. f(x) = x^4/5, a = 32

*March 7, 2013*

**Physics**

A pole-vaulter just clears the bar at 5.34 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3.8E3 J. What is his weight?

*March 6, 2013*

**Physics**

A pole-vaulter just clears the bar at 5.34 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3.8E3 J. What is his weight?

*March 6, 2013*

**Physics**

A pole-vaulter just clears the bar at 5.34 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3.8E3 J. What is his weight?

*March 6, 2013*

**Physics**

A pole-vaulter just clears the bar at 5.34 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3.8E3 J. What is his weight?

*March 6, 2013*

**Physics**

A pole-vaulter just clears the bar at 5.34 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3.8E3 J. What is his weight?

*March 6, 2013*

**Physics**

A pole-vaulter just clears the bar at 5.34 m and falls back to the ground. The change in the vaulter's potential energy during the fall is -3.8E3 J. What is his weight?

*March 6, 2013*

**Physics**

A ladder (L = 7.80 m) of weight WL = 360 N leans against a smooth vertical wall. The term "smooth" means that the wall can exert only a normal force directed perpendicular to the wall and cannot exert a frictional force parallel to it. A firefighter, whose weight is ...

*March 4, 2013*

**Physics**

Two curves on a highway have the same radii. However, one is unbanked and the other is banked at an angle θ. A car can safely travel along the unbanked curve at a maximum speed v0 under conditions when the coefficient of static friction between the tires and the road is...

*March 4, 2013*

**chemistry**

wait is it 79.57g?

*March 2, 2013*

**chemistry**

delta t = i*Kf*m m = mols/kg solvent 4= (3)(1.86) m= 0.717 (0.717)(1000) = 0.000717mol 0.000717mol/110.98g/mol = 6.46 x 10^-6g

*March 2, 2013*

**chemistry**

is the answer 0.079g or 0.00000646g ? I'm not sure if I've done it correctly.

*March 2, 2013*

**chemistry**

If Kf = 1.86C/m, how many grams of calcium chloride must be added to 1.0L of water (assume a density of 1.0 g/mL) to lower the freezing point 4.0 C?

*March 2, 2013*

**Chemistry**

Imagine two solutions with the same concentration and the same boiling point.? Imagine two solutions with the same concentration and the same boiling point, but one has ethanol as the solvent and the other has carbon tetrachloride as the solvent. Determine that concentration ...

*March 2, 2013*

**Chemistry**

A solution is made by mixing 37.0 mL of ethanol, C2H6O, and 63.0 mL of water.? Assuming ideal behavior, what is the vapor pressure of the solution at 20 °C? ethanol: 0.789 g/mL 43.9 torr water : 0.998 g/mL 17.5 torr

*March 2, 2013*

**Math**

Find the number of each kind of object in the collection Miranda has 24 CDs in her collection. Of those CDs, 10 are pop CDs. She has 6 more country CDs than jazz CDs. How many country CDs does Miranda have?

*March 1, 2013*

**physics**

Two curves on a highway have the same radii. However, one is unbanked and the other is banked at an angle θ. A car can safely travel along the unbanked curve at a maximum speed v0 under conditions when the coefficient of static friction between the tires and the road is...

*February 28, 2013*

**physics**

A kite is hovering over the ground at the end of a straight 47-m line. The tension in the line has a magnitude of 14 N. Wind blowing on the kite exerts a force of 17 N, directed 55° above the horizontal. Note that the line attached to the kite is not oriented at an angle ...

*February 28, 2013*

**Chemistry**

The vapor pressure of pure acetone (propanone) is 266 torr. When a non-volatile solute is added, the vapor pressure of acetone above the solution falls to 232 torr. What is the mole fraction of acetone in the solution? Show work. A) 0.69 B) 0.32 C) 0.13 D) 0.045 E) 0.87

*February 27, 2013*

**Chemistry**

Isoamyl salicylate (м = 208.25 g/mol) has a pleasant aroma and is used in perfumes and soaps. Which of the following combinations gives a 0.75 m solution of isoamyl salicylate in ethyl alcohol (d = 0.7893 g/mL)

*February 27, 2013*

**math**

500000

*February 25, 2013*

**Chemistry**

Explain how you would prepare 100.0 mL of 0.500 M NaCl solution. Include the appropriate glassware and calculations.

*February 25, 2013*

**math**

A two digit number has the property that the units digit is 4 less than the tens digit and the tens digit is twice the units digit. What is the number?

*February 18, 2013*

**Physics**

A model rocket launches with an initial velocity of 6 m/s, at an angle of 90 degrees (with respect to the horizon). The rocket's engine provides an acceleration of 2.2 m/s2, acting in the same direction as the initial velocity. After 20 seconds, the rocket engine cuts out...

*February 15, 2013*

**physics**

A spacecraft is on a journey to the moon. At what point, as measured from the center of the earth, does the gravitational force exerted on the spacecraft by the earth balance that exerted by the moon? This point lies on a line between the centers of the earth and the moon. The...

*February 12, 2013*

**physics**

The drawing (not to scale) shows one alignment of the sun, earth, and moon. The gravitational force SM that the sun exerts on the moon is perpendicular to the force EM that the earth exerts on the moon. The masses are: mass of sun = 1.99 1030 kg, mass of earth = 5.98 1024 kg, ...

*February 7, 2013*

**physics**

The weight of an object is the same on two different planets. The mass of planet A is only forty-five percent that of planet B. Find the ratio rA/rB of the radii of the planets.

*February 7, 2013*

**physics**

A rocket of mass 4.5 105 kg is in flight. Its thrust is directed at an angle of 45.5° above the horizontal and has a magnitude of 7.60 106 N. Find the magnitude and direction of the rockets acceleration. Give the direction as an angle above the horizonal.

*February 7, 2013*

**math**

How to name 3300 in 4ways

*February 7, 2013*

**Movement and Music**

which of the following best describes the realation between movement and music a movement and music are parteners because they enhance each other and provide enjoyment

*February 7, 2013*

**English II**

I have to write an satire and I am doing it on the movie The Help.

*February 3, 2013*

**physics**

A hot-air balloon is rising straight up with a speed of 6 m/s. A ballast bag is released from rest relative to the balloon at 7 m above the ground. How much time elapses before the ballast bag hits the ground?

*January 31, 2013*

**physics**

Search: On a pleasure cruise a boat is traveling relative to the water at a speed of 5.4 m/s due south. Relative to the boat, a passenger walks toward the back of the boat at a speed of 1.4 m/s. (a) What is the magnitude and direction of the passenger's velocity relative ...

*January 31, 2013*

**physics**

In a marathon race, Chad is out in front, running due north at a speed of 3.92 m/s. John is 92 m behind him, running due north at a speed of 4.33 m/s. How long does it take for John to pass Chad?

*January 31, 2013*

**physics**

A golfer hits a shot to a green that is elevated 3 m above the point where the ball is struck. The ball leaves the club at a speed of 16.1 m/s at an angle of 41.1° above the horizontal. It rises to its maximum height and then falls down to the green. Ignoring air ...

*January 31, 2013*

**physics**

A golfer hits a shot to a green that is elevated 3 m above the point where the ball is struck. The ball leaves the club at a speed of 16.1 m/s at an angle of 41.1° above the horizontal. It rises to its maximum height and then falls down to the green. Ignoring air ...

*January 31, 2013*

**Physics**

A puck is moving on an air hockey table. Relative to an x, y coordinate system at time t = 0 s, the x components of the puck's initial velocity and acceleration are v0x = +0.8 m/s and ax = +0.9 m/s2. The y components of the puck's initial velocity and acceleration are ...

*January 31, 2013*

**Physics**

As a tennis ball is struck, it departs from the racket horizontally with a speed of 28.2 m/s. The ball hits the court at a horizontal distance of 19.5 m from the racket. How far above the court is the tennis ball when it leaves the racket?

*January 30, 2013*

**Physics**

In a football game a kicker attempts a field goal. The ball remains in contact with the kicker's foot for 0.050 s, during which time it experiences an acceleration of 390 m/s2. The ball is launched at an angle of 46° above the ground. Determine the horizontal and ...

*January 30, 2013*

**Physics**

A meteoroid is speeding through the atmosphere, traveling east at 19.0 km/s while descending at a rate of 12.9 km/s. What is its speed, in km/s?

*January 30, 2013*

**MATH**

AMANDA TEST SCORE ON SIX TESTS WAS 94. FIVE OF THE SIX TEST SCORES WERE 88, 94, 93, 95 & 99. WHAT WAS THE SIXTH TEST SCORE?

*January 29, 2013*

**Math 104**

A poll was taken of 100 students at a commuter campus to find out how they got to campus. The results were as follows: 34 said they drove alone. 24 rode in a carpool. 28 rode public transportation. 3 used both carpools and public transportation. 3 used both a carpool and ...

*January 19, 2013*

**statistics**

The company policy for customer service representatives gives time off for positive reviews. If, in the first 20 calls a customer service agent handles in a day, 13 or more elect to take a subsequent survey and rate the service as “excellent”, then the company gives ...

*January 10, 2013*

**Business math**

$1,097.51?

*January 5, 2013*

**algebra 2**

The label on a prescription bottle directs the patient to take the medicine twice a day. The effective ingredient of the medicine decreases continuously at a rate of 25% per hour. If a dose of medicine containing 1 milligram of the effective ingredient is taken, how much is ...

*December 20, 2012*

**physics**

A student is skateboarding down a ramp that is 6.88 m long and inclined at 16.9 degrees with respect to the horizontal. The initial speed of the skateboarder at the top of the ramp 2.54 m/s. Neglect friction and find the speed at the bottom of the ramp in m/s.

*December 19, 2012*

**chemistry**

What is the type of glycosidic bond in case alpha?

*December 16, 2012*

**chemistry**

When disaccharide beta is hydrolyzed, which monosaccharide units are produced?

*December 16, 2012*

**chemistry**

When disaccharide alpha is hydrolyzed, which monosaccharide units are produced? A) D-glucose and D-fructose monosaccharide units B) two D-fructose monosaccharide units C) two D-glucose monosaccharide units

*December 16, 2012*

**Chemistry**

When disaccharide alpha is hydrolyzed, which monosaccharide units are produced? A) D-glucose and D-fructose monosaccharide units B) two D-fructose monosaccharide units C) two D-glucose monosaccharide units

*December 16, 2012*

**Chemistry**

What mass of solid sodium acetate, NaCH3COO, must be added to 2.50 L of an aqueous solution of 0.55 M acetic acid, CH3COOH, in order to make a buffer solution whose pH is 4.50? Assume that adding the solid does not change the volume of the solution.

*December 15, 2012*

**Statistics**

62.Refer to the Baseball 2009 data, which report information on the 30 Major League Baseball teams for the 2009 season. a. At the .05 significance level, can we conclude that there is a difference in the mean salary of teams in the American League versus teams in the National ...

*December 1, 2012*

**algebra**

f(x)=-2+5 sketch a graph

*November 30, 2012*

**science**

The force that every mass exerts on every other mass is called _________. A. gravity B. pull C. matter D. weight

*November 27, 2012*

**coversion**

150lbs= how many kg when 1kg=2.2 lbs

*November 21, 2012*

**Chemistry**

1.90X10^19 it would remain the same

*November 17, 2012*

**chemistry**

If 8.00g of methane is burned with 6.00g of oxygen. How much methane,oxygen,carbon dioxide,and water remain after the reaction is complete in grams?

*November 12, 2012*

**physis**

A box slides downwards at a constant velocity on an inclined surface that has a coefficient of friction uK = .58 The angle of the incline, in degrees, is most nearly:

*November 9, 2012*

**Chemistry**

A 1.30-L sample of argon gas is at 1.02 atm and 21.5 degrees Celsius. a. what mass of argon is in the container. b. If the temperature is raised to 500 degrees celsius while the volume remains constant, calculate the new pressure, in stmospheres.

*November 9, 2012*

**chemistry**

a 55g aluminum block initially at 27degrees C absorbs 725J of heat. What is the final temp. I know I need to use the equation q=m*Cs*Delta T but I cannot figure out how to rearrange the equation to isolate Tf to get the answer. Thanks for any help.

*November 4, 2012*

**math**

I NEED HELP TO!!!!! SOMEONE PLEASE HELP!!!

*November 2, 2012*

**intermediate algebra**

a basketball player scores 35 times during a gam,e. he scored 57 total point 2 for each 2 point shot and one for each free throw how many two pint shots did he make and how many free throws did he make

*October 29, 2012*

**Algrebra**

substitution method 3x + y=12 8x-2y =4

*October 29, 2012*

**Math**

Find two numbers whose ratio is 4 to 3 and are such that the sum of their squares is 100.

*October 29, 2012*

**math**

an artist is going to an art fair. the artist will charge $20 for small prints $45 for large prints. the artist would like to sell twice as many small prints as large prints. the booth the artist is renting costs $510. how many of each size print must the artist sell in order ...

*October 28, 2012*

**4th grade math**

You can divide 108 into 324 to find the product of 324 x 4 324/108 = 3 or You can Multiply 3 x 108 = 324 to find the product of 324 x 4

*October 19, 2012*

**LATIN**

The new book will belong to the consul

*October 11, 2012*

**LATIN**

How do I say "belong to" in Latin?

*October 11, 2012*

**LATIN**

Thanks!

*October 11, 2012*