Wednesday

March 4, 2015

March 4, 2015

Total # Posts: 856

**AP Chemistry**

A voltaic cell is constructed that uses the following half-cell reactions. Cu+(aq) + e- Cu(s) I2(s) + 2 e- 2 I -(aq) The cell is operated at 298 K with [Cu+ ] = 2.3 M and [I - ] = 3.3 M. (a) Determine E for the cell at these concentrations. (b) If [Cu+ ] were equal to 1.0 M, ...
*April 16, 2012*

**CHEM**

Given the equation 2C8H18 + 25O2 = 16 CO2 + 18H2O: The combustion of octane produces carbon dioxide and water. If you start with 10.0 moles of octane, what mass of water (in grams) would you expect to produce?
*April 3, 2012*

**Chemistry 1201**

thankyou so much! i got 3.65*10^25
*March 28, 2012*

**Chemistry 1201**

A solution of ammonia and water contains 1.00×1025 water molecules and 5.50×1024 ammonia molecules. How many total hydrogen atoms are in this solution?
*March 28, 2012*

**chemistry**

Calculate the enthalpy change for converting 10.0g of ice at -25 degrees Celsius to water at 80 degrees Celsius. The specific heats of ice, water, and steam are 2.09j/g degrees Celsius, 4.18j/g degrees Celsius, and 1.85j/g degrees Celsius. The enthalpy of fusion for water is 6...
*March 28, 2012*

**chemistry**

How do I do a question like this please help and explain it!! Calculate the pH of a buffer solution that contains 0.22 M benzoic acid (C6H5CO2H) and 0.24 M sodium benzoate (C6H5COONa). [Ka = 6.5 × 10-5 for benzoic acid] Round your answer to two places past the decimal.
*March 25, 2012*

**Chem 111**

A solution is prepared by mixing 499 mL of 0.19 M Tris·Base and 592 mL of 0.37 M Tris·Acid. What is the pH of this solution? [Ka(Tris·Acid) = 8.5 × 10-9] Round your answer to two places past the decimal. I can do basic pH questions but I am at a loss...
*March 25, 2012*

**math **

A town has a population of 32,000 in the year 2002; 35,200 in the year 2003; 38,720 in the year 2004; and 42,592 in the year 2005. If this pattern continues, what will the population be in the year 2016?
*March 10, 2012*

**geography**

Which region of southern grasslands in south america have rich deposits of oil and bauxite?
*March 9, 2012*

**geography**

which region of the southern grasslands possesses rich deposits of oil and bauxite?
*March 9, 2012*

**Chemistry**

21 gCH3OH*(1 mol/32.01CH3OH)*(252.8/1 mol)
*March 5, 2012*

**Chemistry**

2CH3OH(g)->2CH4(g)+O2(g) Change in H=252.8 kJ
*March 5, 2012*

**Chemistry**

So far my equation is 21 gCH3OH*(1 mol/32.01CH3OH)
*March 5, 2012*

**Chemistry**

Calculate the amount of heat transferred when 21.0 of CH3OH(g) is decomposed by this reaction at constant pressure.
*March 5, 2012*

**Chemistry**

A gaseous reaction occurs at a constant pressure of 50.0 atm and releases 69.8 kJ of heat. Before the reaction, the volume of the system was 8.80 L . After the reaction, the volume of the system was 2.80 L . Calculate the total internal energy change, change in U , in kilojoules.
*March 5, 2012*

**Adv. Function math**

How would you set up this problem if instead of using 1000 feet of fencing, only 750 feet of fencing is used? Solve the problem to find the maximum area..
*February 29, 2012*

**Finance**

Say that you purchase a house for $270,000 by getting a mortgage for $235,000 and paying a $35,000 down payment. If you get a 15-year mortgage with a 8 percent interest rate, what are the monthly payments?
*February 27, 2012*

**Physics Please Help!**

A solid disk with a mass ok 100 kg and radius of 0.2m turns clockwise through an angular displacement 10 rad when starting from rest attain its maximum angular speed of 1 revolution every 0.5s. How much time did it take for the disk to go from rest to maximum angular speed?
*February 21, 2012*

**Physics**

A solid disk with a mass ok 100 kg and radius of 0.2m turns clockwise through an angular displacement 10 rad when starting from rest attain its maximum angular speed of 1 revolution every 0.5s. How much time did it take for the disk to go from rest to maximum angular speed?
*February 21, 2012*

**PHYSICS**

A solid disk with a mass of 100kg and a radius of 0.2m, turns clockwise through an angular displacement 10 rad when starting from rest to attain its maximum angular speed, of 1 revolution every 0.5s. What is the angular acceleration that the wheel experienced in order to ...
*February 20, 2012*

**Physics**

A solid disk with a mass of 100kg and a radius of 0.2m, turns clockwise through an angular displacement 10 rad when starting from rest to attain its maximum angular speed, of 1 revolution every 0.5s. What is the angular acceleration that the wheel experienced in order to ...
*February 20, 2012*

**algebra**

use any three of the digits 2,3,4 and 6 to form an 8 digit factor and a two didgit factor with a estimated product that is between 140 and 250
*February 18, 2012*

**phi 103**

no fallacy committed
*February 12, 2012*

**Physics**

ohh okies thanks for clearing that up (:
*February 12, 2012*

**Physics**

i mean.. mr^2w+Iw = mr^2w+Iw ... which is equivalent to L+L = L+L
*February 12, 2012*

**Physics**

I don't really understand we use I1w1=I2w2? but according to your equation its mr^2+Iw = mr^2+Iw ... which is equivalent to I+L = I+L <-- i dont get this part? and the answer is 0.568 rev/s which according to your way is right but its 19 instead of 29.
*February 12, 2012*

**Physics**

A turntable of radius 2m rotates freely about a fixed vertical axis. A child 19 kg is standing on the turntable right at the outer edge and the system is initially rotating at an angular speed of 0.5 rev/s. The child then moves to position 1m from center of the turntable. what...
*February 12, 2012*

**algebra**

At a local ice cream shop, you can choose from a collection of 18 different toppings. If you want to choose at least one topping, how many different topping combinations are possible (assuming no repeat toppings)?
*February 6, 2012*

**statistics**

Sweden is reported to have among the highest percentage of citizens aged 80 years and over, at approximately 5.5 % (i.e. 5.5 % of it's population falls within this age category). Suppose 20 individuals are randomly selected from the population, and X is the number of ...
*February 5, 2012*

**math**

From an exteror point P that is h units form a circle of radius r, a tangent line is drawn to the circle. Let d denote the distance from the point P to the point of tangency T. Express d as a function of h.(HINT: if C is the center of the circle, the PT is perpendicular to CT)
*January 30, 2012*

**biology**

Explain the importance of carbon's ability to form covalent bonds in straight chains, branched chains, or rings.
*January 24, 2012*

**chemistry**

What mass of H2SO4 would be required to react with 0.59 mol of NaOH?
*January 19, 2012*

**Math**

How do I find the relative maximum and minimum and the zeros of f(x)=-x^3+16x^2-76x+96??
*January 15, 2012*

**english**

what does SS stand for in Shurley Method?
*January 4, 2012*

**Geometry**

(3,-6)
*December 16, 2011*

**phyics**

Find the horizontal range of a baseball that leaves the bat at an angle of 63 degrees, with the horizontal with an initial velocity of 160 km/hr. discard air resistance
*December 14, 2011*

**physics**

the diver acheives a horizontal velocity of 3.75 m/s from a diving platform located 6.0 m above the water. How far from the edge of the platform will the diver be when she hits the water?
*December 14, 2011*

**Statistics**

A study shows that 10% of americans are left-handed. Find the probability that at most one student is left handed in a class of 20 students.
*December 9, 2011*

**Trig**

1. Establish the identity: sin(theta+3pi/2)=-cos(theta) 2. Find the exact value of 2(theta) if sin(theta)=5/13 3. Show that: csc2(theta)-cot2(theta)=tan(theta) 4. Find the exact value of tan(cos^-1(square root of 3/2) 5. Approximate the value rounded to two decimal places: csc...
*December 7, 2011*

**science**

which of the following is a testable hypothesis helium, ammonia, oxidation-reduction?
*December 6, 2011*

**physics**

A hockey player shoots a puck, exerting a constant force of 30.0 N on the hockey puck for 0.16 seconds. What is the magnitude of the impulse given to the puck? 190 kg ∙ m/s 98 kg ∙ m/s 9.6 kg ∙ m/s 4.8 kg ∙ m/s
*December 2, 2011*

**geometry**

the angles in a pentagon measure x-30,x+20,x-30, x+30 and x find the measure of each angle.
*November 28, 2011*

**geometry**

the angles in a hexagon are 135, 62, 151, 140, x and x +6. find the measure of the missing angles.
*November 28, 2011*

**chemistry**

What is the solubility of silver carbonate in 0.1 M Na2CO3
*November 17, 2011*

**chemistry**

What is the solubility of silver carbonate (Ag2CO3) in pure water
*November 17, 2011*

**world history**

How did powerful families of Japan like the Fujiwara legitimate their power at court?
*November 8, 2011*

**geometry**

If the sum of the lenghts of two sides of a triangle is 15, what is the largest possible integral value for the third side?
*October 17, 2011*

**chemistry**

PE increases
*October 11, 2011*

**Language**

Buttering
*October 6, 2011*

**Algebra 2**

How do you find a shaded area of a rectangle of 24 ft and 40 ft and 100 ft
*October 1, 2011*

**help please!:-)**

It wasn't right :(
*October 1, 2011*

**World History 201**

I need help with one T or false guestion. I don't know if this is true or false As a christian, persian king khosrow I forbade zoroastrian teaching troughout his empire.
*September 28, 2011*

**Chemistry**

Find the volume of 0.110 M hydrochloric acid necessary to react completely with 1.54 Al(OH)3. Please explain how to do this.
*September 28, 2011*

**Please help!**

Find the volume of 0.110 M hydrochloric acid necessary to react completely with 1.54 Al(OH)3. Please explain how to do this.
*September 28, 2011*

**Help please:-)**

What is the most important key to an effective essay?
*September 28, 2011*

**Chemistry**

Find the volume of 0.110 M hydrochloric acid necessary to react completely with 1.54 Al(OH)3. Please explain how to do this.
*September 28, 2011*

**Algebra 1 Scientific Notation**

1.462828271x10^99
*September 26, 2011*

**math**

the sum of the lenths of any two sides of a triangle must be greater than the third side. if a triangle has one side that is 17 cm and a second side that is 4cm less than twice the third side, what are the possible lenths for the second and third side?
*September 26, 2011*

**Algebra**

A runner wants to run 11.6 km. She knows that her running pace is 8.1 miles per hour. How many minutes must she run?
*September 22, 2011*

**geometry**

A.
*September 22, 2011*

**Chemistry**

For the following acid-base reaction, calculate the mass (in grams) of each acid necessary to completely react with and neutralize 5.00 g of the base. HCl(aq)+ NaOH(aq)->H20(l)+NaCl(aq) Please explain how to do this.
*September 16, 2011*

**social studies**

why might the earliest farming communities have developed along the Nile,Tigris,and Euphrates
*September 15, 2011*

**social studies**

how did rivres in southwest asia enrich the soil
*September 15, 2011*

**math**

the cube of what number is 2197?
*September 14, 2011*

**physics**

A baseball player hits the ball at a speed of 20.1 m/s and an angle of 30 degrees. What is the baseball's horizontal velocity? What is the baseball's vertical velocity? How long does it take the baseball to get 28m in front of home plate?
*September 11, 2011*

**physics**

ummmmmmmmmmmm who the heck are you??? im asking a simple physics question if you have a problem then you can take it somewhere else darling:)
*September 11, 2011*

**physics**

A baseball player hits the ball at a speed of 20.1 m/s and an angle of 30 degrees. What is the baseball's horizontal velocity? 1m/s What is the baseball's vertical velocity? 2m/s How long does it take the baseball to get 28m in front of home plate? 3 seconds
*September 11, 2011*

**7th grade social studies**

how did rivers enrich the soil
*September 7, 2011*

**Chemistry**

Boron has only two naturally occurring isotopes. The mass of boron-10 is 10.01294 amu and the mass of boron-11 is 11.00931 amu. Use the atomic mass of boron to calculate the relative abundance of boron-10. Atomic mass of boron is 10.81 How do I solve this?
*September 7, 2011*

**Chemistry**

Thank you!
*September 7, 2011*

**Chemistry**

An alpha particle,4He2+ , has a mass of 4.00151 . Find the value of its charge to mass ratio in C/kg. How do I solve this?
*September 7, 2011*

**Chemistry**

What is the chemical name for BeCrO4*5H2O?
*September 7, 2011*

**math**

Find the distance that the earth travels in seven days in its path around the sun. Assume that a year has 365 days and that the path of the earth around the sun is a circle of radius 93 million miles. [The path of the earth around the sun is actually an ellipse with the sun at...
*September 2, 2011*

**Chemistry**

That's how I did it but the computer said it was wrong. I guess I'll have to ask the teacher about it. Thanks for your help!
*August 31, 2011*

**Chemistry**

Carbon-12 contains 6 protons and 6 neutrons. The radius of the nucleus is approximately 2.7 (femtometers) and the radius of the atom is approximately 70 (picometers). The volume of the nucleus is 8.2×10^−8 pm^3 And the volume of the atom is 1.4×10^6 pm^3 I ...
*August 31, 2011*

**geometry**

If X=5 units, x=11 units, h=10 units, what is the area of trapezoid shown above
*August 28, 2011*

**history**

what animal was a source of food for early hunters yet is not in existence today?
*August 18, 2011*

**history**

Where do archaeologists believe early Americans came from?
*August 18, 2011*

**Math**

Samual is 5 in , taller than Jackie - 8 shelly is 0.7 in taller than Jackie whos taller?
*August 18, 2011*

**Math**

The temperature at 3:00 am was -17 f by noon the temperture was -17.8 f at what time was it the coldest?
*August 18, 2011*

**math**

Evaluate write in simplest form Y - for y = -6 and z = -20 z
*August 18, 2011*

**CalcULUS**

nevermind
*July 16, 2011*

**CalcULUS**

Find slope of f(x)=x^3–2x^2+2x+2 on the interval (–3–1).
*July 16, 2011*

**CALCULUS**

Consider the function f(x)=sqrt(2–5x^2), –5≤x≤1. The absolute minimum value is ____ and this occurs at x equals ______? Found the max value to be 2 at x=0.
*July 16, 2011*

**math**

Thanks Reiny it helped alot
*July 12, 2011*

**physics**

A 3 kg toy car with a speed of 10 m/s collides head-on with a 2 kg car traveling in the opposite direction with a speed of 3 m/s. If the cars are locked together after the collision with a speed of 4.80 m/s, how much kinetic energy is lost?
*June 26, 2011*

**Algebra 1**

complete. 6t to the 2nd power - 23t + 20=(3t - 4)(2t - .....)
*June 26, 2011*

**Algebra 1**

Complete. g to the 2nd power - 8g+16=(g - 4)(g....4)
*June 26, 2011*

**Math**

Luis is 10 years older than his brother. Next year, he will be three times as old as his brother. If the brother's age is represented by a, what is Luis' age? What will be the brother's age next year?
*June 26, 2011*

**statistics**

Suppose you want to test the claim that mu is not equal to 3.5. Given a sample size of n = 31 and a level of significance of alpha = 0.10 when should you reject Ho? A) Reject Ho if the standardized test statistic is greater than 2.575 or less than -2.575. B) Reject Ho if the ...
*June 21, 2011*

**peresonal finance**

how does education plays a critical role in financial success
*June 3, 2011*

**American Studies**

Affordable housing and improved transportation allowed people to begin to move away from central cities to the suburbs Think: When did affordable housing and highways come about? The industrial revolution gave rise to urbanization Think: When was the first occurrence of ...
*May 28, 2011*

**American Studies**

Identify two causes of urbanization (growth in city life) and explain how each changed the geography of the United States.
*May 28, 2011*

**calculus**

Pretend the program in Senegal had been reducing infant mortality at a rate of 12.2 % per year. How long would it take for infant mortality to be reduced by 31 %?
*May 15, 2011*

**chemistry**

If you accidentally spill phosphorus-32 onto your shoe, how long would it take before 99.9 of the radioactive material has decayed so that you can safely wear the shoes again?
*May 12, 2011*

**math **

heelp me with scientific nottion
*May 2, 2011*

**history**

In the 1950's, how did some corperations expand to protect themselves against the dangers of economic downturns?
*April 26, 2011*

**families in crisis**

What are some of the unique challenges facing Native American (Indian American) families, as described in pp. 471-487 in Ferguson? (Shifting the Center: Understanding Contemporary Families by Susan Ferguson) How is ageing seen differently in the Apache community than it is ...
*April 21, 2011*

**Chemistry**

A 10.0 ml sample of vinegar which is an aqueous solution of acetic acid, requires 16.5ml of a 0.500M NaOH solution to reach the endpoint in a titration (where the moles of acid are equal to the moles of base). What is the molarity of the acetic acid solution?
*April 19, 2011*

**finance**

It would take 11 years
*April 14, 2011*

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