Friday

August 28, 2015
Total # Posts: 992

**college chem**

1.43e2
*March 9, 2010*

**Chemistry**

If 15.0 kJ are released when 1.40 g of F2 reacts with an excess of SiH4, complete the thermochemical equation below. SiH4(g) + 2 F2(g) SiF4(g) + 4 HF(g) ÄHrxn = ?kJ
*March 8, 2010*

**Chemistry**

Several of my classmates and I use this website. I use my own name.
*March 8, 2010*

**Chemistry**

94.0 g of a metal at 88.0°C are added to 55.0 g of water at 26.0°C. When the system reaches constant temperature, the temperature is 39.3°C. What is the specific heat of the metal? The specific heat of water is 4.184 J/g·°C.
*March 8, 2010*

**Chemistry**

What is the specific heat of a substance if 35.5 kJ are required to raise the temperature of 345 g of the substance from 69.0°C to 150.0°C?
*March 8, 2010*

**Chemistry**

Copper has a specific heat of 0.387 J/g·°C. How much energy is required to raise the temperature of 140. g of copper from 17.5°C to 154.0°C?
*March 8, 2010*

**Chemistry**

A 5.80 g sample of SiH4 and an excess of oxygen were placed in a reaction container surrounded by 3.40 kg of water. The initial temperature of the water was 14.10°C. At the end of the reaction, the temperature of the water was 48.90°C. Assume the heat was completely ...
*March 8, 2010*

**math cont.**

i forgot one of the questions to the math question i just asked. calculate your yearly salary after six years as a veterinary tech.
*March 2, 2010*

**math**

what? i did. ive already done this question twice and my teacher said i did it wrong both times
*March 2, 2010*

**math**

at the start of your school year as a veterinary tech, you receive a raise of $750. you expect to receive the same raise every year. your total yearly salary after your first raise is $18,000 per year write an equation that models your total salary (s) in terms of the number ...
*March 2, 2010*

**Linear Equations**

Solve the following system of equations by the substitution method. 8x = 2y + 5 3x = y + 7
*March 2, 2010*

**college**

TiO2(s) + H2(g) Ti(s) + H2O(g) (a) Consider the unbalanced equation above. What is the maximum mass of titanium that can be produced when 2.65 g of TiO2 and 3.40 g H2 react? = ?g Ti (b)Assume the reaction in part (a) goes to completion. Calculate the mass of excess reactant. =?g
*February 28, 2010*

**precalculus**

The question is...find the radian measure of the central angle of a circle of radius r that intercepts an arc of length s. Then it gives the radius r of 27 inches and an arc length s of 6 inches. How do I do that?
*February 28, 2010*

**calculus**

what he said
*February 21, 2010*

**3rd grade math**

13
*February 18, 2010*

**English 101, Politics**

Thank you for that. I will continue trying to figure this out.
*February 16, 2010*

**English 101, Politics**

I would like a starting point, I really don't understand the question. I am not good with politics at all. I've been researching it but I'm still at a loss.
*February 16, 2010*

**English 101, Politics**

This is for my English 101 class, I have to write a 3 page paper. Why did the recent history of liberalism and neoconservatism curiously mirror and parallel the modern African American civil rights movement?
*February 16, 2010*

**1st grade**

it breathes it eats it grows it moves it reproduces
*February 16, 2010*

**geometry**

X lies in the interior of <abc Name the two angles contained in <abc
*February 9, 2010*

**physics**

If you are initially 1.50 km [E] of home and 0.65 hours later you are 0.75 km [N 45 degrees E] of home, what is your change in displacement?
*February 8, 2010*

**physics**

If you are initially 1.50 km [E] of home and 0.65 hours later you are 0.75 km [N 45 degrees E] of home, what is your change in displacement?
*February 8, 2010*

**writing**

in acts of resistance what is the tone of scarry introductory paragraph?
*February 3, 2010*

**6th grade math**

(D)
*February 1, 2010*

**Finite**

Assume that the producer has 8 skits and 5 commercials available. In how many ways can the producer create a television show?
*January 24, 2010*

**science**

does an animal cell have a cell wall
*January 21, 2010*

**science**

parts of a animal cell
*January 21, 2010*

**maths**

what number is 40 more than 454?
*January 19, 2010*

**social studies**

What is the country that lies north of the eastern Canada?
*January 18, 2010*

**social studies**

what happens in the ending of the movie seasbiscuit and how does it reflect the struggles of the depression?
*January 12, 2010*

**music**

who was the lyrist of joesph and the technicolour dreamcoat
*January 4, 2010*

**Technology**

what is a insulator?
*January 2, 2010*

**Technology **

what is a conductor?
*January 2, 2010*

**Technology**

What is a electron?
*January 2, 2010*

**Literature**

I am taking the exact same class, and they sound perfect! (:
*December 29, 2009*

**Hospitality: food, shelter, and fun away from home**

Compare the “8 Things to Look for in a Franchise” on the Web page with the “Seven Basic Questions for a Prospective Franchisee” in the textbook. Discuss in detail the similarities and differences between the two.
*December 11, 2009*

**chemistry**

THANKS SO MUCH DRBOB!! I GOT THE CORRECT ANSWER!!!!!
*November 28, 2009*

**chemistry**

determine the percent by mass of all the elements in the compound magnesium sulfate heptahydrate? how do i start this? mg is 24.31 sulfur is 32.07 and 7 hydrogens for heptahydrate? add them up? 63.436. if i am doing this correctly what do i do next?
*November 28, 2009*

**chemistry**

yes paul i am. im having a blast trying to do this extra credit. how its it going for you?
*November 28, 2009*

**chemistry**

disregard the last post i meade. i submitted it and i realized i forget to add the87.56 into the work! Ba 137.33 2Cl 70.9 2O 32 = 240.23 2Cl 70.9/240.23 Xs 100= 29.51% 0.2951 X 87.56mg= 25.84mgCl 25.84 Xs 1mol/35.45= 0.729 X 6.022= 4.39 X 10 to the 23 power. is that correct?
*November 28, 2009*

**chemistry**

ok. so i have: Ba 137.33 2Cl 70.9 2O 32 = 240.23 2Cl 70.9/240.23 Xs 100= 29.51% i need mg not g so i convert it 29.51 in mg =0.02951 correct? if so i have 0.02951mgCl X 1mol/35.45 X 6.022 X 10 to the 23= 0.00083244 X 6.022= 0.005 X 10 to the 23 power. am i on the correct path?
*November 28, 2009*

**chemistry**

how many atoms of chlorine are ther in 87.56 milligrams of barium chlorite?
*November 28, 2009*

**Math**

Find the amount of money in an account after 12 years if $1000 is deposited at 5% annual interest compounded quarterly.
*November 20, 2009*

**5th grade Language**

yes Mrs. Sues answers are corecct I got an A+
*November 5, 2009*

**physics**

0.06
*November 4, 2009*

**Sixth Grade Social Studies**

Need help with finding the state capitals of the middle and southern colonies from the 1600's
*November 3, 2009*

**Histor**

What were low points in King Henry VIII's reign?
*October 27, 2009*

**math**

what kind of music do barbers and tailors play together?
*October 23, 2009*

**science**

The density of a 1.0 M solution of NaCl is 1.04 g/mL and its specific heat, c, is 3.06 J/C*g. How much heat is absorbed by 3.14 mL of this solution if the temperature rises from 18.6C to 29.7C? q=m*C*delta T (1.04g)(3.06)(11.1K)=35.32 is that right?
*October 22, 2009*

**science**

thanks
*October 22, 2009*

**science**

To What change of state does the term fusion apply? Gas??
*October 22, 2009*

**College Physics**

A boy of mass 64.1 kg is rescued from a hotel fire by leaping into a firefighters' net. The window from which he leapt was 7 m above the net. The firefighters lower their arms as he lands in the net so that he is brought to a complete stop in a time of 0.40 s. Ignore air ...
*October 15, 2009*

**College Physics**

The graph shows the force exerted on an object versus the position of that object along the x-axis. The force has no components other than along the x-axis. If z is an increment of 25, then what is the work done by the force on the object as the object is displaced from 0 to 3...
*October 13, 2009*

**College Physics**

A spring fixed at one end is compressed from its relaxed position by a distance of 0.20 m. See the graph of the applied external force, Fx, versus the position, x, of the spring. (a) Find the work done by the external force in compressing the spring 0.17 m starting from its ...
*October 13, 2009*

**College Physics**

A record company executive is on his way to a TV interview and is carrying a promotional CD in his briefcase. The mass of the briefcase and its contents is 4.00 kg. The executive realizes that he is going to be late. Starting from rest, he starts to run, reaching a speed of 2....
*October 13, 2009*

**6th grade**

How do you know that the particles are moving in a solid?
*October 12, 2009*

**Medical Physics**

A block is acted on by a force that varies as (2.8*10^4 N/m)x for 0<=x<=.21m, and then remains constant at 5880 N for larger x. 1. How much work does the force do on the block in moving it from x = 0 to x = 0.30 {m}? 2. How much work does the force do on the block in ...
*October 2, 2009*

**science**

3. Makes bubbles when added to vingar
*October 2, 2009*

**Physics**

Jenny are there any numbers for forces?
*October 2, 2009*

**french**

so maybe imperfect? Je n'avais pas..?
*October 2, 2009*

**french**

Can someone help me with this sentence? Quelquefois, je me suis senti inadéquate parce que je n'ai pas acquis beaucoup d'expérience en dessin. my teacher circled "n'ai pas" i do not know what is wrong with it:(
*October 2, 2009*

**College Physics**

A cyclist starts from rest and pedals so that the wheels make 7.7 revolutions in the first 5.1 s. What is the angular acceleration of the wheels (assumed constant)?
*September 25, 2009*

**College Physics**

A turntable reaches an angular speed of 33.3 rpm, in 2.0 s, starting from rest. (a) Assuming the angular acceleration is constant, what is its magnitude? (b) How many revolutions does the turntable make during this time interval?
*September 25, 2009*

**College Physics**

A wheel's uniform angular acceleration is constant. Initially its angular velocity is zero. During the first 1.0 s time interval, it rotates through an angle of 86.0°. a) Through what angle does it rotate during the next 1.0 s time interval? (b) Through what angle ...
*September 25, 2009*

**College Physics**

A pendulum is 0.50 m long and the bob has a mass of 1.0 kg. At the bottom of its swing, the bob's speed is 1.6 m/s. What is the tension in the string at the bottom of the swing?
*September 25, 2009*

**College Physics**

A spy satellite is in circular orbit around Earth. It makes one revolution in 5.99 hours. (a) How high above Earth's surface is the satellite? (b) What is the satellite's acceleration?
*September 25, 2009*

**US History**

that isn't helpful at all sra!
*September 24, 2009*

**Physics**

A bobcat weighing 74.5 N jumps out of a tree. (Assume that "up" is the positive direction.) (b) What is the drag force on the bobcat when it falls at 70% of its terminal velocity? (d) What is the acceleration when it falls at 70% of its terminal velocity?
*September 23, 2009*

**Physics**

A paratrooper with a fully loaded pack has a mass of 119 kg. The force due to air resistance on him when falling with an unopened parachute has magnitude FD = bv^2 where b = 0.13 (N·s^2)/m^2. The force of air resistance acting on him is 516N up. (b) What is his ...
*September 23, 2009*

**Physics**

A car is speeding up and has an instantaneous speed of 14.2 m/s when a stopwatch reads 9.1 s. It has a constant acceleration of 1.8 m/s^2. (a) What change in speed occurs between t = 9.1 s and t = 12.6 s? (b) What is the speed when the stopwatch reads 12.6 s?
*September 23, 2009*

**Physics**

Two blocks are connected by a lightweight, flexible cord that passes over a frictionless pulley. If m1 is 3.4 kg and m2 is 9.1 kg, and block 2 is initially at rest 130 cm above the floor, how long does it take block 2 to reach the floor?
*September 23, 2009*

**Pre-Algebra**

I know the answers but I don't know the equations to match it to plz help 1. 33 5x+3 2. -26 9x+10 (that's all I know) 3. 40 4. -69 5.-16 6.12 7.-82 8.33 9.72 10.-43 11.99 12.-73 13.76 14.181
*September 15, 2009*

**5th grade**

Make a product to find each product of 2 x 2500
*September 9, 2009*

**Pre Calc**

Solve the equation on the interval [0,2pi). cos2x=(*2/2)
*August 27, 2009*

**Pre Calc**

Solve the equation on the interval [0,2pi). cos2x=(*2/2)
*August 26, 2009*

**Pre Calc**

How did you get n?
*August 26, 2009*

**Pre Calc**

Use the Leading Coefficient Test to determine the end behavior of the polynomial function. f(x)=-3x^3-3x^2-2x+1 ?????????????
*August 26, 2009*

**science**

how do you figure mass, volume & density using D=m/v v=m/d mass =dxv m
*August 25, 2009*

**calculus**

factor the polynomials 3n(squared)+8n=4 8x(to the third) - 6x(squared) - 27x - 54
*August 25, 2009*

**geometry**

2 times square root of 27 minus square root of 18 plus 3 times squareroot of 27=
*August 13, 2009*

**Math Functions**

If f(x)=x^2-2 and g(x)=1/(3x) (x does not equal 0), find: (f+g)(x)
*July 27, 2009*

**Grade 7**

What are some facts that could be used to prove the history of "the ameicans won the war of 1812 I have looked and looked and looked and I can't really find anything. Could someone please help by giving me some facts or places that I can look really confused, thanks
*June 30, 2009*

**Social**

Should powerful nations interfere in a civil war that is occuring in another nation?
*June 10, 2009*

**cooking**

go to cookinginthekitchen and search Mama Laura's super fondant. I've tried it so many times, even at my daughters wedding. There are no bad comments either
*May 23, 2009*

**5th grade**

he wanted no slavery
*May 21, 2009*

**Quantum Mechanics**

i think you must be in my pchem class.. i solved this problem differently from above: I used the same method as example 7-2 and homework problem 7-9 in McQuarrie. I assumed that since the nucleus consists of just one proton, the radius of the nucleus is the radius of a proton ...
*April 28, 2009*

**Technical Writing**

Using presentation software, when do you use certain layouts? I am looking for the "why" and "when" here, not the "how to." I am mainly concerned about: -two-column text -content over text -text over content -default title and text Thank you, maigan
*April 13, 2009*

**Accounting**

What circumstances would moral standards approach to stakeholder impact analysis be most useful?
*April 9, 2009*

**math**

For Jerome the chances are 3/8 (if all of the runners had equal ability). For Morgan, after Jerome had gotten first (let's say he did) then his chances would be 2/7. And for Bly his chances are 1/6. Now you have got to multiply them all together. (3/8) (2/6) (1/6) = 1/56 i...
*April 9, 2009*

**2nd grade math**

thats a stupid question-- and im a first grade teacher,... wow
*April 2, 2009*

**biology**

what is the stages of mitosis?
*March 30, 2009*

**health**

In which condition is the patient most likely to hemorrhage? A. Thrombocytopenia B. Polycythemia C. Thalassemia D. Erythroblastosis fetalis I think the answer is (A)
*March 26, 2009*

**Language**

One particularly nice afternoon, several students were trapped in a classroom listening to a monotonous lecture by a professor the local college. After over two hours of mind-numbing discourse, one student stood up in despair and noted that she had a book with every word of ...
*March 2, 2009*

**science**

What is the journey of a cheese sandwich-digestion?
*February 28, 2009*

**10th grade Geometry**

Lorenzo's model train is 1/87 the size of the original train. He measures the engine of the model train and finds that it is 2.5 inches tall. What is the height of the real engine to the nearest foot?
*February 26, 2009*

**college algebra word problem**

A goldsmith has two alloys that are different purities of gold. The first is 3/4 pure and the second is 5/12 pure. How many ounces of each should be melted and mixed in order to obtain a 6 oz mixture that is 2/3 pure gold?
*February 25, 2009*

**college algebra**

Solve the problem. A man rode a bicycle for 12 miles and then hiked an additional 8 miles. The total time for the trip was 5 hours. If his rate when he was riding a bicycle was 10 miles per hour faster than his rate walking, what was each rate?
*February 25, 2009*

**Chemistry**

For each of the following unbalanced equations, suppose that exactly 15.0g of each reactant is taken. Determine which reactant is limiting, and calculate what mass of each product is expected. assume the limiting reactant is completely consumed. a)Al+HCL->AlCl3+H2 b)NaOH+...
*February 16, 2009*

**math**

the heaviest human of all time weighed 486 kg this is 12 kg less than 6 times juans weight. how much does juan weigh?
*February 5, 2009*

**math**

the width of a photograph is 4 cm more than 3/10 of the length. if the widthis 13 cm find the length
*February 5, 2009*