Questions Asked on
March 26, 2008

chemistry
Given: *Fe2O3(s)+3CO(s)>2Fe(s)+3CO2(g)(delta h is 23kJ) *3Fe2O3(s)+CO(g)>2Fe3O4(s)+CO2(g)(delta h is 39kJ) *Fe3O4(s)+CO(g)>3FeO(s)+CO2 (delta h is 18kJ) Desired:FeO(s)+CO(g)>Fe(s)+CO2(g) find delta h for the desired reaction. which reactions do i
asked by tanisha 
chemistry proofread
write the chemical equations for the following sentences a) Aluminum reacts with oxygen to produce aluminum oxide I put Al + O2 > 2Al2O3 b) Phosphoric acid, H3PO4, is produced through the reaction between tetraphosphorous decoxide and water I put
asked by john 
Physics
A steam engine's boiler completely converts 155 kg of water to steam. This process involves the transfer of 3.5 x 10^8 J by heat. If steam escaping a safety valve does 1.76 x 10^8 J of work against the outside atmosphere, what is the net internal energy of
asked by Lindsay 
physics  energy question
A simple pendulum, 2.0 m in length, is released with a push when the support string is at an angle of 25° from the vertical. If the initial speed of the suspended mass is 1.2 m/s when at the release point, what is its speed at the bottom of the swing? (g
asked by icy 
grammar
Identify the homonym the day, month, and year / a sweet fruit with a hard seed
asked by chase 
PHYSICS
An underwater scuba diver sees the sun at an apparent angle of 45 degrees from the vertical. What is the actual angle of the sun? i don't know how to get the answer but the book says its 19.5 degrees can anyone help me?
asked by nat 
Physics
Calculate the work done by planet X on its moon. Planet X applies a force of 5.6 x 10^10 N on its moon and the moon is 4.0 x 10^8 km away from the planet and it continues to circle the planet in a circular orbit of circumference of 2.5 x 10^9 m.
asked by Marty 
physics
A child looks at his reflection in a spherical tree ornament 12 cm in diameter, and sees an image of his face that is reduced by onefourth. How far is his face from the ornament? I don't know what I would do with the given information. I know that M=q/p
asked by Anonymous 
Physics
Why are the steam and ice points of water better fixed points for a thermometer than the temperature of a human body?
asked by Jim 
SCIENCE
According to the law of conservation of mass, how does the mass of the products in a chemical reaction compare to the mass of the reactnats?
asked by SONITRA 
physics => really need help on 2 problems (#1)
A house has well insulated walls. It contains a vol of 100m^3 of air at 300K a) calculate the E required to increase the T of the diatomic gas by 1.00C b) If this E could be used to lift an object of mass m through a height of 2.00m what is the mass of m?
asked by ~christina~ 
physics
In a television picture tube, electrons strike the screen after being accelerated from rest through a potential difference of 25000V. The speeds of the electrons are quite large, and for accurate calculations of the speeds, the effects of special
asked by Cindy 
Calc
Find a cartesian equation for the curve described by the given polar equation. a. r=2 b. r=3sin pheta c.r^2=sin2pheta I don't understand how to solve for this, especially for r squared. Would someone plz explain how o convert to a cartesian equation. any
asked by Jessica 
last chem ?
complete each of the following synthesis reactions by writing both a word equation and a chemical equation a) sodium + oxygen> ___________ b) Magnesium + Fluorine >_______
asked by john 
physics!
An electric car accelerates for 8.0s by drawing energy from its 320V battery pack. During this time, 1300C of charge pass through the battery pack. Find the minimum horsepower rating of the car. I need some ideas to do it!!PLEASE HELP!!!THANK YOU SO
asked by Karmen 
Physics
Two people start at the same place and walk around a circular lake in opposite directions. One has an angular speed of 1.2 103 rad/s, while the other has an angular speed of 3.4 103 rad/s. How long will it be before they meet?
asked by Erich 
English expression
Look at the bingo board. There are nine sentences in nine boxes. Look at the small bingo board over the big one. There are three sentences having shortened words in three boxes. You should write down six more senetnces containing contractions in the six
asked by John 
Physics
A boy weighing 40kg runs at 8.0m/s grabs a rope and swings of level ground. What maximum height does the child reach? How do I solve this?? it is under the conservation of energy section of work, power and energy. any help would be great! thanks
asked by Steven 
Physics
At a height of 3.00 m above the ground, a 0.500kg ball is thrown with an initial speed of 30.0 m/s in an arc from point A to point C. When the ball is 6.00 m above the ground travelling upward, what is the speed of the ball?
asked by Marty 
Social Studies Civil War
1) Should the North help the South or not because they lost the Civil War? 2) Should Southerners be forgiven if they swear loyalty to the U.S.? 3) When a majority of Southerners pledge their loyalty to the U.S., should they be allowed back in the Union? 4)
asked by Joy 
Physics
These are questions that follow a lab on resonance with tuning forks and a resonance tube in a waterfilled graduated cylinder in part 1 (closed tube), and tuning forks with a sliding tube in part 2 (open tube). What are some applications of this study of
asked by Mike 
Physics (forgot to post this question #2)
During the compression stroke of a certain gasoline engine, the pressure increases from 1.00atm to 20.0atm. If the process is adiabatic and the fuel air mixture behaves a a diatomic ideal gas a) by what factor does the volume change b) by what factor does
asked by ~christina~ 
Calc
Find a polar equation for the curve represented by the given Cartesian equation. a. y=5 b.2xy=1 I know i posted a question just for the opposite..Im confused on how to convert the other way around as well. any advice?
asked by Jessica 
science
because they are the simplest units of structure and function capable of life, cells are often called the ______ of life.
asked by cassie 
history
Were the Korean and Vietnam Wars part of the Cold War? Thanks!
asked by Liam 
chemistry
Copper (II) flouride contains 37.42% F by mass. Use this percentage to calculate the mass of flourine (in grams) contained in 35.6 g of copper (II)fluoride.  How many grams of Cl are present in 55g of CFCl3?
asked by Anonymous 
Science fair project
Anyone know of sites on compostie softball/baseball bats?
asked by Chey 
John Jay
Where can I find the correct meaning of the following terms: Stereotype, Gender group, Pluraism, Sociology, Minority group, Assimilation, Conflict perspective, Segregation, Ethnic group, Racism, Class Subordinate group, Social construction of race, Racial
asked by Stacey 
Physics
Which object in the following pair has greater total internal energy, assuming both objects in the pair are in thermal equilibrium? a 1kg block of ice at 25 degrees Celsius or seven 12g ice cubes at 25 degrees Celsius
asked by Jim 
chemistry
How many butane molecules are present in a sample that contains 5.0 moles of butane? (Butane C4H10) What would be the mass of 75 moles of butane?
asked by Kate 
math
A standard tip for a waiter or waitress is between 15% and 20% of the bill. If Sue wants to tip 20% of her $45.00 dinner bill, how much should she leave the waiter as a tip?
asked by marquis 
algebra 1
juan drives to work. Because of traffic conditions, he averages 22 miles per hour. He returns home averaging about 32 miles per hour. the toatle time traveled is 2 and 1/4 hours.define a variable for the time Juan takes to drive to travel to work write an
asked by nathan 
Physics
During a tennis serve, a racket is given an angular acceleration of magnitude 155 rad/s2. At the top of the serve, the racket has an angular speed of 13 rad/s. If the distance between the top of the racket and the shoulder is 1.5 m, find the magnitude of
asked by Zach 
science small intestine
how does mechanical digestion occur in the small intestine? What three enzymes are involved in chemical digestion of small intestine and what 3 sugars do they break down?
asked by john 
computers
When I get to the series part of Microsoft Excel 2003 during graphing, what am I supposed to do?
asked by Nina 
Law
Discuss some of the possible motivations of a whitecollar criminal. Why would the CEO of a Fortune 500 company embezzle money? In addition, discuss some strategies you would suggest as a business's security manager to discourage whitecollar crime. Can
asked by April 
Algebra
How do I solve the equation: 4x + 3 = x = 12 using a pan balance?
asked by Ashley 
Physics DC Circuit
A 2 ohm r2 ohm r    ___ 5 ohm r 3 ohm r     ___ _ 2 ohm r  ___     I3     
asked by Bobby 
AP PHYSICS
An electron and a proton are initially very far apart (effectively an infinite distance apart). They are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.29*10^.11m. What is the change in
asked by Becky 
physics
if it costs 4.5 to 7.5 cents per kilowatthour (wind energy) what is the price per kW?
asked by Tim 
Calc
Find the cartesian coordinates of the following points given in polar coordinates. b. (2 rt2, 3pi/4) I cant figure this one out
asked by Jessica 
chemistry 1
k2=[H][SO4]/[HSO4] .012=(.01+x)(x)/(.01x) Solve for x, and calculate pH where H is .01+x When I am solving for x does it become .012= .01x + x^2/ .01 x.. what is the next step of solving for x?
asked by lyne 
geography
Need to know the principal rivers, mountains, and bodies of salt and fresh waters within and around China, Taiwan, Japan, North and South Korea. Thanks.
asked by Dave 
managerial economics
You have a friend who is always getting into trouble by taking unwise risks. What advice would you give this person? What advice would you give someone you believe to be excessively wary of risk? Also, assume you are an investor in the stock market. What
asked by jean 
Physics
The burning of gas in a car produces about 12,600 kJ/gallon of energy. If a car averages 35 km/gal when driving 90 km/hr, which requires 18.5 kW, what is the efficiency of the engine under those conditions? ...please help?
asked by Lindsay 
memorization
does anybody have any tips on memorizing things? i have to memorize one of juleit's speeches in romeo and juliet in act 2 scene 1. Please help!!
asked by anonymous 
Gen Chemistry
What is the pH ( 3 significant digits) of a 0.01 M solution of sulfuric acid? Hint is that the first ionization constant is "large", and the second is finite, and the [H+] donated by the second equilibrium depends upon the amount of [H+] already donated by
asked by lyne 
Maths (coordinate geometry)
two lines y=2x+6 and y=1.5x+1 intersect. What is the size of the acute angle at the intersection? Ive got 59.4 degrees. Any confirmation/slight alteration?
asked by Mikal 
Math
Write each of the following ratios in simplest form. The ratio 5 3/5 to 2 1/10
asked by Ms. Teri 
Spanish year 1
Puedes jugar al tenis conmigo? No,no ___________jugar al tenis. a. juegas b.jugamos c.puedes d. se with a tilde or whatever over the e I think it says Can you play tennis with me? and the choices are you play, we play, you can, and I know how, but it seems
asked by Alehanda 
Work and Family Life (WFL)
For my Work and Family Life class I my teacher gave us a picture of a child. Everyone has a child from a different country. My girl is from South Africa. On the back of the picture it talks about the girl (age, name ect. ). Then it says the child's
asked by Taylor 
Physics
A battery with voltage drop of 120V is connected in a ciruit containing both series and parallel. Moving in a clockwise direction. R1= 3 ohms. Suddenly there is a connection of point A to point B. In between these two points is a parallel circuit with R2=
asked by Andrea 
math
How would I write the following quadratic function in standard form? The function is (9x+2)^2+4x? What is the process for changing this to standard form?
asked by Claire 
physics
A gyroscope consists of a rotating uniform disk with a 60cm radius, suitably mounted at one end of a 15cmlong axle (of negligible mass) so that the gyroscope can spin and precess freely. Its spin rate is 1540rev/min. What is the rate of precession if
asked by kelly 
Science
What solid melts at 35 degrees celsius
asked by Alex 
chemistry
Posted by lyne on Tuesday, March 25, 2008 at 11:44pm. What is the pH ( 3 significant digits) of a 0.01 M solution of sulfuric acid? Hint is that the first ionization constant is "large", and the second is finite, and the [H+] donated by the second
asked by lyne 
Physical Chemistry
Let's say we are given 1.0 mol of an ideal gas, and we are given a starting temperature, and and initial pressure the gas exerts. We are now told that the gas expands adiabatically until it reaches some other pressure, p2. How do we calculate w and dH for
asked by AJ 
science
name two factors that affect gravitional force exerted on an object?
asked by MTH 
Equations and variables
Why are variables and equations such an important part of algebraic reasoning?
asked by Sarah 
Math
Write the proportion that is equivalent to the given statement If Maria hit 8 home runs in 15 softball games, then she should hit 24 home runs in 45 games.
asked by Ms. Teri 
job search
plan for a job search by considering how you would manage the 'resume', job application letter, interview, and followup letter.
asked by Anonymous 
ENGLISH
I REALLY NEED HELP ON THIS. I WOULD BE GRATEFUL IF SOMEBODY COULD FIGURE IT OUT: A A A AIRBORNE AND AND AND AND AND AND BECOMES BILLS CO2 CONSTRUCTION CONVERSION DECK DISRUPTIVE DUST DUSTY EXPENSIVE FAR GO HEATING IN INSULATES LESS LOFT LOFT MOISTURE ONE
asked by harry 
chemistry
for each of the following synthesis reaction indentify the missing reactant(s) or product(s) and then balance the resulting equation a) Mg +__________ > MgO b) _________ + O2> Fe2O3 c) Li + Cl2 > _________ d) Ca +
asked by john 
English expression
The th in brother is a voiced sound, and the th in three is a voiceless sound. Do you know how to pronounce the th sound? Stick out your tongue between upper teeth and lower teeth, that is, put your tongue between your upper teeth and lower teeth and say
asked by John 
math...help me! this is hard!!!!
you have three jugs and a river of water. The jugs are known to hold exactly 3, 7, and 10 liters. How can you use these jugs to measure exactly 5 liters of water?
asked by Kelly 
English expression
Let's play the 'who is it' game, in which the appropriate person stands up. Class, first, stand up. I will ask you questions. If your answer is 'Yes, I do' or 'Yes, I am', you should remain standing. However, if your answer is 'No, I'm not' or 'No, I
asked by John 
statistics
What does the area corresponding to the critical value zcrt mean? There is a graph that has a normal bell shape curve that has a vertical arrow that intersects the x axis far from the y axis. then everything to the left of the the vertical arrow is colored
asked by stats 
social studies
what is the capital and distribution of smoothies
asked by nya 
Dr.Bob
I replied to that post from yesterday. I don't know if you saw it.
asked by ~christina~ 
Science 8th grade
What is it called if you get pain in you leg when you walk and the pain stops if rest ?
asked by Anonymous 
World Religion
How does the NICA help Natives advance
asked by Sara 
Physics
The following appliances are being used simultaneously: toster oven, TV, computer, three 100 W light bulbs and an iron. Yet the circuit breaker (15 A) has not tripped. Does that necessarily mean that not all of these appliacnces are connected to a single
asked by Andrea 
Algebra
What misconceptions do children have about expressions such as 4+8 and the equal sign that can cause difficulty working with equations?
asked by Mike 
Algebra
What is algebraic reasoning? What does it mean?
asked by Jordon 
chem
What is the pH ( 3 significant digits) of a 0.01 M solution of sulfuric acid? Hint is that the first ionization constant is "large", and the second is finite, and the [H+] donated by the second equilibrium depends upon the amount of [H+] already donated by
asked by lyne 
chem
Next step, multiply both sides by (.01x) .012(.01x)=.01x+x^2 gather terms, put in standard binomial form, use the quadratic equation, and solve for x. is the standard binomial x^2+.022x1.2x10^4
asked by lyne 
math
Next step, multiply both sides by (.01x) .012(.01x)=.01x+x^2 is the binomial x^2 + .002x1.2x10^4 what is the next step is the answer .021 and .023 for x
asked by lyne 
chem
DrBob has given you the equation to use: k2 = [H^+][SO4^]/[HSO4^] and the values to substitute [H^+] = 0.01 + x [SO4^2] = x [HSO4^] = 0.01  x k2 = 1.2 x 10^2 you need to substitute these and solve for x. Remember that you are after 0.01+x [H^+] to
asked by lyne 
U.S. History
Any websites (about) or knowledge of: U.S. economic trends throughout the ‘60s, ‘70s, and ‘80s.
asked by Saleshia 
Math
what does this, ~, mean?
asked by Chey 
biology
Is a starch molecule smaller or larger than an iodine molecule?
asked by Claire 
microsoft excel 2003
How would I graph equations in Microsoft Excel 2003 and the residuals? I want to graph linear, quadratic and exponential equations but I don't know how.
asked by Nina 
Marketing
Hello, My group has been assigned to do a General Market Survey on a foreign country (we picked France). Can anyone give us some pointers on what topics/statistics to include, where to find information, anything at all? We are to use secondary data to
asked by Chloe 
english
why do mail trucks have one seat
asked by alyssa 
algebra 1
i need the rate of change for: growing from 1.4 to 1.6m in one year
asked by taylor 
Communication
What characteristics of reporting enable you to judge whether or not information is reliable? Please use examples of specific people, events, or phenomena to support your answer.
asked by Jean 
ecology
what does commensalasion mean and give an example
asked by m 
science
how does GOES help meteorologists
asked by Anonymous 
Science 8th grade
please check my answer thanks True or false Blood gains oxygen when it passes through the liver I said True
asked by Anonymous 
algebra
Explain three rules for exponents
asked by janet barnes 
social studies
Where can I find the Flags of Texas in order?
asked by Ken 
algebra
Can someone tell me if I did this the right way? It seemed easy but it makes me worried that I did it wrong. h is not equal to 0 f(x)=7x9 f(x+h)f(x)/h= 7(x+h)9(7x9)/h= 7x+7h97x+9/h= 7h/h= 7
asked by sara 
history
What does classsystem and classstate mean? I can't find the meanings in the dictionary.
asked by laney 
Physics
In a certain process, 2.11x10^5 J of heat are supplied to a system and at the same time, the system expands against a constant external pressure of 6.89x10^5 Pa. Given that the temperature of the system does not change, find the increase in volume of the
asked by Lindsay 
Business Studies
hi why do brand names are dold at a higher price ? So for example even though we have two identical products , one with a brand name , and the other without , why will the brand name have a more chargable price ?
asked by Student 1 
Algebra
What misconceptions do children have about expressions such as 4+8 and the equal sign that can cause difficulty working with equations?
asked by sarah 
English  Critique Essay Please
This is how much I've done so far, not finished yet but could you see if I'm on the right track? I'm following the structure of Introduction, 3 Main Body Paragraphs and a Conclusion. Explain how the themes of prejudice and tolerance are explored in the
asked by TP 
english
can you make me a sentence out of the word interracial
asked by chequan 
Apartheid
What are the four rules of apartheid?
asked by Cindy 
Math
Marc took 3 hours (h) to mow a lawn while Angelina took 150 minutes (min) to mow the same lawn a week earlier. Write the ratio of Marc’s time to Angelina’s time as a ratio of whole numbers
asked by Ms. Teri 
Math
Find each rate. 240 pounds of fertilizer 6 lawns
asked by Ms. Teri 
Math
What are the steps to doing y = mx + b case for system of linear equations?
asked by Selene