Wednesday
February 10, 2016

Posts by Andrea

Total # Posts: 753

Chemistry
why would acetic acid concentration of a good vinegar need to be known for commercial reasons and regulatory health and safety reasons
December 3, 2010

Chemistry
suppose a pippetting error was made when preparing the diluted vinegar, but the diluted vinigar solution was uniform and the naoh titration values were consistant. when will the student learn that the experiment result was not accurate explain
December 3, 2010

Chemistry
A student did not fully mix the solution of Oxalic Acid in the volumetric flask predict and explain the effect of the range of the students titration volumes when using the NaOH solution to titrate the Oxalic Acid solution
December 2, 2010

Chemistry
what are 1 or 2 causes of loss of product that you may observe when synthesising a coordination compound sorry more detail we were synthesising Copper sulfate pentahydrate CuSO4.5H2O And Potassium oxylate dihydrate K2C2O4.H2O
November 29, 2010

Chemistry
how could you improve the product yeild if you had to redo the synthesis
November 29, 2010

Chemistry
what are 1 or 2 causes of loss of product that you may observe when synthesising a coordination compound
November 29, 2010

Chemistry
if it takes 20 h to convert 100g of reactant A to roduct C at 20 degrees celcius, approximately how many minutes would it take at 110 degrees celcius? I know the answer, I just don't know how to get the answer
November 28, 2010

Spanish
Thank you-that's where I was confused
November 28, 2010

Spanish
If this is what they are saying in Spanish- "Yo me llamo Joey.“ Vivo en Chicago pero soy de Springfield. “ How would I answer these two questions? ¿De dónde es Joey? ¿Dónde vive? Thank you
November 28, 2010

Chemistry
The following reaction is used to produce tungsten(VI)oxide: WS3(s) + O2(g) ¨ WO3(s) + SO2(g) The WO3 is then heated and undergoes a decomposition reaction produce tungsten and oxygen gas. How many grams of tungsten could be produced if 39.27 grams of WS3 are used
November 25, 2010

Chemistry
Given the following reaction: HCl(g) + SrO(s) ¨ SrCl2(s) + H2O Calculate the mass of HCl in grams that would react with 11.44 kg SrO.
November 25, 2010

social studies
what do the egyptians stuff in the eye sockets of mummies?
November 22, 2010

Chemistry
What are the sizes of BCl3, CCl4, NCl3, and Cl2O in comparison to one another. For example BCl3<CCl4<NCl3.... I know that isn't right but I need to know this to find difference in bond lengths and some of these molecules are close together in size so I'm not sure...
November 18, 2010

physics
A 40%-efficient car engine accelerates the 1300 kg car from rest to 20 m/s How much energy is transferred to the engine by burning gasoline? .
November 13, 2010

physics
A 30 kg child slides down a playground slide at a constant speed. The slide has a height of 3.8m and is 7.8m long. using energy considerations, find the magnitude of the kinetic friction force acting on the child.
November 5, 2010

Psychology
Why do you believe that researchers would want to see if there isa correlation rather than just fully testing ech variable?
November 4, 2010

Physics
Two metal spheres, each weighing 24.0 kg are placed 0.0500 m apart. Calculate the magnitude of the gravitational force the two spheres exert on each other.
November 3, 2010

Chemistry
A solution of ethanol (C2H5OH) in water is prepared by dissolving 61.9 mL of ethanol (density = 0.79 g/cm3) in enough water to make 250.0 mL of solution. What is the molarity of the ethanol in this solution?
October 27, 2010

english
what is the difference between direct and indirect references?
October 24, 2010

3rd grade
Yes
October 20, 2010

chemistry
Suppose 150.0 mL of 0.50 M HCl and 150.0 mL of 0.50 M NaOH, both initially at 24.0°C, are mixed in a thermos flask. When the reaction is complete, the temperature is 27.4°C. Assuming that the solutions have the same heat capacity as pure water, compute the heat ...
October 18, 2010

college
A coin dealer, offered a rare silver coin, suspected that it might be a counterfeit nickel copy. The dealer heated the coin, which weighed 14.0 g to 100°C in boiling water and then dropped the hot coin into 29.5 g of water at T = 15.0°C in an insulated coffee-cup, and ...
October 18, 2010

Chemistry
I'm really confused.. I got .92 % is that correct?
October 17, 2010

Chemistry
If 5.86g of glucose are reacted and 1.44L of CO2 gas are collected at 293K and .984atm. What is the percent yield of the reaction? C6H1206 -> 2C2H5OH + 2CO2
October 17, 2010

history
Why is the studying the history of Western ideas helpful for understanding your ideal of social or political and aesthetic developments today/ Explain
October 13, 2010

Physics
Consider an inefficient engine which draws 200 J of heat from a hot reservoir at 100oC, converts 48 J to work, and rejects 152 J to a cold reservoir at 0oC. Theoretically, how much maximum work can be produced if the efficiency of the engine is maximized? How much work was &#...
October 6, 2010

Physics
One gram of water is placed in a cylinder and the pressure is maintained at 2.0 x 105 Pa. The temperature of the water is raised by 31oC. Determine the change in internal energy when, a) the water is in its liquid phase and causes an expansion of 1.0 x 10-8 m3. b) Water is in ...
October 6, 2010

Physics
An ideal gas in a rigid container (constant volume) has its pressure cut in half slowly. In the process, 265 kJ of heat left the gas. (a) How much work was done during the process? (b) What was the change in internal energy of the gas during this process?
October 6, 2010

College Physics
Margaret walks to the store using the following path: 0.420 miles west, 0.265 miles north, 0.300 miles east. What is her total displacement? That is, what is the length and direction of the vector that points from her house directly to the store?
October 4, 2010

physics
is the answer 123.79 kg? or Newtons? thank you for the help
September 20, 2010

physics
The two angled ropes used to support the crate in the figure below an withstand a maximum tension of 1300 N before they break. The left angle is 30dregres, and the right angle is 45degrees. What is the largest mass the ropes can support? m=?
September 20, 2010

5th grade
How did a bill become a law??
September 14, 2010

English
Thank you
September 7, 2010

English
The climax of "The Lottery" is when: A.The Hutchinson family is selected as the lottery winners B.Tessie is selected as the final lottery winner C.Tessie is stoned to death by the village I'm leaning towards B but I'm not sure if maybe it is C but I think C ...
September 7, 2010

English
I think selection "a" about the village residents gather for a lottery, etc: Is that correct?
September 7, 2010

English
Who is the main character of "The Lottery" and what best describes the story's plot? I think the main character is Yessis Hutchinson, correct? Which best describes the plot? Answers: A.Village residents gather for a lottery, one family is named the winning family...
September 7, 2010

Physics
If someone could point me in the right direction-please!!! A car with an initial speed of 4.30m/s accerlerates uniformly at the rate of 3.00 m/s ^2. Find final speed after 5.00s. Thanks for any help you can provide.
September 5, 2010

Physics
With an average acceleration of negative 1.2m/s squared, how long will it take a cyclist to bring a bicylcle with an initial speed of 6.5 m/s to a complete stop? answers are: either 2.0, 5.4. 0.18 or -1.8s Please help-I am totally confused
September 1, 2010

algebra
in 1990, the life expectancy of males in a certain country was 68.1 years. in 1995, it was 70.9 years. let E represent the life expectancy in year t and let t represent the number of years since 1990 F(x)=
August 1, 2010

physics
A racing dog is initially running at 15.0 m/s, but is slowing down.How fast is the dog moving when its kinetic energy has been reduced by half? By what fraction has its kinetic energy been reduced when its speed has been reduced by half?
July 18, 2010

finance
You have found three investment choices for a one year deposit: 10% APR compounded monthly, 10% APR compounded annually, and 9% APR compounded daily. Compute the EAR for each investment choice. Assume that there are 365 days in the year.
July 12, 2010

Physic
How many kilometers would you have to go above the surface of the earth for your weight to decrease to half of what it was at the surface?
July 10, 2010

Physic
A bowling ball weighing 71.2 N is attached to the ceiling by a 3.60 m rope. The ball is pulled to one side and released; it then swings back and forth like a pendulum. As the rope swings through its lowest point, the speed of the bowling ball is measured at 4.00 m/s. At that ...
July 10, 2010

Physic
What is the period of revolution of a satellite with mass m that orbits the earth in a circular path of radius 7820 km (about 1450 km above the surface of the earth)?
July 10, 2010

Physic
An unstretched spring is 11.0 cm long. When you hang an 590 g weight from it, it stretches to a length of 14.0 cm. what is the force constant in (N/m) of this spring? what is the total mass must you hang from the spring to stretch it to a total length of 18cm?
July 10, 2010

Physic
thanks i got the answer :)
July 10, 2010

Physic
with the speed of 8.60m/s and slides 38m
July 10, 2010

Physic
A hockey puck leaves a player's stick with a speed of 8.60 and slides 38.0 before coming to rest. Find the coefficient of friction between the puck and the ice.
July 10, 2010

BIOLOGY TEACHER
Biology teacher help me with two questions. what role do microorganisms play in ecological succession? describe ecological succession in terms of changes in the abiotic parts of an ecosystem
July 7, 2010

BIOLOGY KK think I got it
microorganisms are nonliving and the ecological succession changes the abiotic parts in an ecosystem.
July 7, 2010

BIOLOGY
what role do microorganisms play in ecological succession? they play role in ecosystem by occuping a niche. have i got it down correct?
July 7, 2010

Biology/ms. sue
I don't get how to describe the ecological succession in terms of changes in the abiotic parts of an ecosystem. What words do i use to describe all that, i can't just insert my example as an answer in my work, what do I do?
July 7, 2010

Biology/ms. sue
ms. sue help =-(
July 7, 2010

ms sue y u not helping me
ms sue i wanna get this done before going to sleep, please provide me with help, atleast the first question, i don't get it. could you give me a small anser so i can atleast figure whats going on.
July 7, 2010

BIOLOGY teacher ms sue
but i don't know how to put that into an answer, can you please help out
July 7, 2010

BIOLOGY teacher ms sue
So for ex. the cutting of trees reduces oxygen(air)?
July 7, 2010

BIOLOGY teacher ms sue
so for ex. the clearing of parcel of land which would bring out the plants. is this what ur looking for?
July 7, 2010

BIOLOGY teacher ms sue
Could you put that question in simple terms so i can understand. Im talking about this one describe ecological succession in terms of changes in the abiotic parts of an ecosystem.
July 7, 2010

BIOLOGY
what role do microorganisms play in ecological succession? they play role in ecosystem by occuping a niche. have i got it down correct?
July 7, 2010

BIOLOGY
so it's the tundra.
July 7, 2010

BIOLOGY
could ya tell me what sand dune and wetland refer to?
July 7, 2010

BIOLOGY
which of the following are mature(climax) communities? a tundra b sand dune c temperate rainforest d wetland I'm guessing it's sand dune or wetland
July 7, 2010

BIO teacher help
it means nonliving things in an ecosystem like sunlight, temperature, etc.
July 7, 2010

BIO teacher help
could ya look again? i said yes i do know what it abiotic means.
July 7, 2010

BIO teacher help
i really dont understand that question.
July 7, 2010

BIO teacher help
ms sue i got an answer
July 7, 2010

BIO
yeah, things that are nonliving like sunlight, temperature, etc.
July 7, 2010

BIO
2.Overfishing and replacement of commercially valuable fish by trash fish. 3.Severe forest fires when forests are protected from fires.
July 7, 2010

BIO
how do I describe, didn't I already do that before?
July 7, 2010

?????????
ms sue help me i don't get it
July 7, 2010

BIO
So meaning flooding, fire, pollution?
July 7, 2010

BIO
I just don't know what the question is asking me to do, I don't know how to describe. Ecological succession is the long-term process of natural vegetation communities changing. The community of plants in an area largely determines what animal life will be part of that ...
July 7, 2010

BIO
I really need help with this question, Damon gave me an answer, but I do not know if it is for this question or for the one posted after. This is the only question I need help on, I promise not to post any other questions after this I need help
July 7, 2010

BIOLOGY
which of the following are mature(climax) communities? a tundra b sand dune c temperate rainforest d wetland I'm guessing it's b - sand dune
July 7, 2010

Ecology
I need help
July 7, 2010

???????????
What role do micro-organisms play in ecological succession?
July 7, 2010

MAJOR HELP NEEDED
So this is what I have to do and I really don't get it. I've gotta describe ecological succession in terms of changes in the abiotic parts of an ecosystem. What do I do? Ecological succession refers to the changes that take place over time in the types of organisms ...
July 7, 2010

chemistry
when 45g of an alloy is dropped into 100.0 g of water at 25c, the final temperature is 37c. what is the specific heat of the alloy
May 19, 2010

chemistry
What is 24388 in scientific notation? And. Give the answer to the following calculations in the proper number of significant figures? a. 25,30cm x 0.035cm.
May 16, 2010

chemistry
How many significant figures are in each of the following a.234 b. 2500 c.0.0034. d. 12.00 e. 0.01010
May 16, 2010

2nd grade
She says, "Look in the backyard for rocks."
April 28, 2010

physical science
Inside the cylinders of a diesel engine, the mixture of fuel and air is compressed to about 1/20 of its original volume. although diesel engines have no spark plugs to ignite this mixture, it ignites anyway because_. a) increases in temperature decrease molecular motion b) ...
April 12, 2010

physical science
the same force is constantly applied to two moveable objects. the more massive object will a) travel at the same speed as the lighter one b) increase speed but at a slower rate than the lighter one c) increase speed but at a greater rate than the lighter one d) increase speed ...
April 12, 2010

physical science
a weather balloon filled with gas is released and rises into the atmosphere. as it rises, the balloon__. a) gets smaller because air pressure outside the balloon increases b) gets smaller because gas pressure inside the balloon decreases c) doesnt change size d)gets larger ...
April 12, 2010

phsyical science
the weight of an object is a) the force of earths gravity b) measured in kilograms c) the amount of matter it contains d)never changes no matter where the object moves in our solar system e) the number of particles it contains
April 12, 2010

Pysical Science
Suppose I give you 2kg of a substance at 90 degree C with a specific heat of .75 cal/g degree C. How much ice water will it take to cool the sample to 20 degree C?
April 8, 2010

Chemistry
You have a 1 L container of F2 at 20 degrees C and 1 atm. Subtract the weight of the container , what is the mass of the gas
March 31, 2010

chemistry 121
Microwave ovens use microwave radiation to heat food. The microwaves are absorbed by moisture in the food, which is transferred to other components of the food. As the water becomes hotter, so does the food. Suppose that the microwave radiation has a wavelength of 11.2 cm How ...
March 27, 2010

chemistry 121
Microwave ovens use microwave radiation to heat food. The microwaves are absorbed by moisture in the food, which is transferred to other components of the food. As the water becomes hotter, so does the food. Suppose that the microwave radiation has a wavelength of 11.2 . How ...
March 26, 2010

bio
bacteria
March 26, 2010

6th grade
the change is the difference between final velocity and initial velocity 5-1 = 4m change in velocity
March 26, 2010

spanish
a large familia has a lot and a small family has little
March 23, 2010

Stress factors
chronic stress because it is long lasting compared to short term or acute stress.
March 20, 2010

Social Studies
northwest florida indian tribe
March 17, 2010

math
288
March 12, 2010

math
A balloon in the shape of a sphere is deflating. Given that t represents the time, in minutes, since it began losing air, the radius of the ballon (in cem) is r(t)=16-t. Let the equation V(r)= 4/3 pi r^3 represent the volume of a sphere of radius r. Find (V (open dot) r)(t)
March 12, 2010

Environmental Science
1) Will there be reduced refuse production by our osciety if we can't find new landfills? (I said no because people are apathetic and will do what they've always done). 2)Will the landscape be covered by pyramids if we can't find new landfills? (I said yes because ...
February 26, 2010

Environmental Science
Can someone please explain to me what SEMASS stands for? I googled SEMASS acronym but no site was able to explain what it means and why it's significant.
February 26, 2010

Science
how does a tornado happen?
February 26, 2010

Math
Todd's wieght went from 220 lbs to 190 lbs and Cassidy's wighte went from 150 lbs t?o 135 lbs. Who had the greater percentage of weight loss
February 17, 2010

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