# chemistry! URGENT

60,378 results, page 9

### Chemistry- urgent!

When a solution of sodium oxalate (Na2C2O4) is added to a solution of lanthanum (III) chloride, lanthanum oxalate (molar mass 541.86 g/mol) The balanced net ionic equation for the reaction is: 3C2O4^2- (aq) + 2La^3+ (aq) --> La2(C2O4)3 (s) Thirty ml of 0.2000 M sodium ...

### chemistry URGENT (2)

Label each of the following reactions as exothermic or endothermic ("exo" or "endo"), and according to whether work is done on or by the system ("on" or "by")? Note that no "en-on" cases appear here, as these are always thermodynamically unfavourable. There is no need to do ...

### Urgent Math

Growing up,you lived in a village. When you left for college, the population was 840. You recently heard that the population has grown by 5%. What is the percent population?

### URGENT DUE TOMORROW! PLEASE! MATHS HOMEWORK.

Each carriage of a train has 45 people which includes 3 stewards and 1 guard. The train has 12 carriages. How many passengers are on the train?

### Geometry urgent!

If the radius of the two areas is 12in find the length of a chord of an arc of 45 degrees, 30 degrees and 60 degrees. I really don't know what to do here! Please help!!

### Math- urgent

The second of two numbers is five more than the twice first. The sum of the numbers is 44. Find the numbers. Show all work.

### calc urgent

let P be the portion of the disk x^2 + y^2 <= 1, lying in the first quadrant. having mass density of p=x, if the mass of P is 1/3 , find the y coordinate of the center of mass of P. the answer is 3/8

### Math

Sean is playing a game where you toss a coin and roll a number cube. How many possible outcomes?Show it as a fraction,decimal, and a percent. If p= probability, what is P( heads,odd)??? Please answer very urgent!!!!

### Science, Urgent!

Polaris is also known as the North Star. Atares has the same apperent magnatude as Polaris. Explain how this can be given that the H-R diagram places it in a different size and luminosity category?

### Math-Gr.11 urgent

The 10th term of an arithmetic series is 34, and the sum of the first 20 terms is 710. Determine the 25th term. Can someone please explain how to do this? I don't know which formula to use. TIA

### Algebra (urgent!)

Write the equations of four lines that intersect to form a square whose sides are not parallel to the axes. Where would I start, and how would I complete this? Thank you so much in advance!

### math

If cotalpha = root 3, calculate (sin alpha)*(cot alpha) - cos^2alpha exactly. can you plzzz help urgent because I have a major test tommorow thnx for all your help

### values and ethics subject please help me urgent pls

miss sue can you help me and example.or anyone can help me to make a relection of this subject...thank you.. “People forget how fast you did a job – but they remember how well you did it.” howad newton

### Physics(urgent)

A stream of water from the nozzle of a fire hoZe emerges horizontally with a speed 16m/s. the nozzle is 20m above the ground, find the time ot hits the groun

### Physics(urgent)

A stream of water from the nozzle of a fire hoZe emerges horizontally with a speed 16m/s. the nozzle is 20m above the ground, find the time ot hits the groun

### physics URGENT! PLEASE

Figure the resultant velocity of a plane that is traveling at 300 km/hr @ 190 degrees when he encounters the wind below a) 30 km/hr tailwind b) 40 km/hr headwind c) 50 km/hr wind blowing south

### BIOCHEMISTRY. PLEASE HELP! URGENT!!!!!

Appreciate if you could help me answering the following questions! thank you!! How would you prepare a 20% homogenate from a 2.0g of liver using 0.25M sucrose? why is it necessary to cool the homogenate during homogenization?

### English I Speech

Can anyone please share their idea of a strong, powerful hook, background information and thesis about fracking? Please this urgent. Be quick like your life depends on it.

### SOCIAL STUDIES URGENT!!

Which of the following would NOT be considered an institution? (1 point) families sports clubs organized religion civilizations this is hard umm i believe it's civilizations am i correct~

### Urgent! Please help!

A house costs $289,000. With a 5% down payment, 2 points due at closing, and the rest financed for 25 years at 6.0% fixed interest, what is the total cost of the house?

### Math

3. The rectangle has an area of 1 square unit. What is the value of x? The length of the rectangle is (3)/(x+2) The width is (2)/(x-3) I can't seem to figure this out, could some please help me? I'm in urgent need of help as this assignment is due tomorrow... Thanks for any help!

### algebra

PLEASE HELP ITS URGENT Pizza costs $1.50 per slice. Use a table and an equation to represent the relationship between the number of slices of pizza bought and the total cost.

### Chemistry urgent for my LAB today (22.09.11)

0.250g of phthalic acid is dissolved in 40.00cm^3 of 0.100 mol dm^-3 NaOH. It requires 11.80 cubic centimeters of 0.100 mol\dm^-3 HCL fo neutralisation( to phenolphthalein) The mole ratio in which phthalic acid reacts with sodium hydroxide ihn 1:2 (a) Calculate the moles of ...

### Chemistry Urgent Help and Check Please!

a) You use 100 ml ethylchloride (density 0.92 g/ml) to extract 25 ml ethylene bromohydrin (density 2.41 g/ml) mixed with 100 ml. Is the aqueous layer the lower or the upper layer. How could you easily test this. ----- Ethylchloride is less dense so it is the top layer Ethylene...

### Chemistry (Urgent)

Ksp of PbI2 at 25 degrees celcius and 15 degrees celcius is 7.5×10^-8 and 7.5×10^-9 respectively. (Pb=207 I=127) 1) write an expression for the equilibrium of PbI2 2)write an equation for the Ksp of PbI2 3)calculate the solubility of PbI2 at 25 degrees celcius in gdm^-3 4)...

### Career Urgent

can some find me sites about cons (negative) being a web designeror you can tell me what are the cons are. I need 3 cons for this assignment please and thank you

### HELP! URGENT! (geometry)

Helen stands 66 m away from the base of the tree. If the line of sight makes an angle of 30 with the top of the tree with respect to the horizon. What is the height (h) of the tree?

### science

how can i prepare this solution? Dissolve 24.82g of sodium thiosulphate in each cubic decimeter of solution to make astock of 0.1M. Dilute this solution 20-fold. URGENT PLEASE!!!!!!!!!!!!!!!

### Chemistry (URGENT)

How many Al atoms thick is the aluminum foil if it is 0.00157cm thick. 1 Al atom = 286pm Convert pm to m 286pm = 2.86*10^-10m Convert m to cm 2.86*10^-10m = 2.9*10^-8cm Divide aluminum thickness and Al atom thickness 1.57*10^-3 / 2.9*10^-10 = 54138 So the aluminum foil is ...

### Chemistry (URGENT)

In order to analyze the waste water containing Co^2+ from a manufacturing process, 1.0L of water was evaporated to 10.0mL, then placed in a spectrophotometer tube. The absorbance was found to be 0.20. Using your calibration curve, calculate the number of milligrams of co^2+ in...

### Chemistry - repost

Why 7ml of 10M HCl? Do I add 7ml of 10M HCl 1st slowly in ice bath, then slowly adjust the pH to 7 using 10M HCl? Then to dilute to 15ml in a graduated cylinder? Thanks Posted by candy on Tuesday, September 21, 2010 at 10:03am. The following is part of a procedure for a limit ...

### 12 Biology--THIS IS URGENT

In relation to a work sheet on translation and transcription: If you worked backward, starting with the amino acid sequence of the protein, would you obtain the same DNA nucleotide sequence? Why or why not? THANKS!!!

### science...URGENT

How are well developed soils similar to young soils? How are they different? Please help... i don't knoiw anything about it. pleae don't ask me to refer to my book... i don't have it with me...i googled it but i don't get any specific answer....plz help

### Clarify (URGENT)

Write a paragraph explaining what generalizations you can make about yourself when looking at the things that are most important to you or the things you value? I don't understand what it means. Can someone simplify it for me please? Thanks.

### urgent calculus

The position of a particle moving in a straight line is given by s(t) = 2sint - cost , from 0 to 2 pi where s is the displacement in metres and t is the time in seconds. Find the absolute max and absolute min displacements.

### British Lit----URGENT

In James Joyce's "The Dead", Gabriel experiences an epiphany. This helps to make him a A)flat character B)stereotype C)round or D)Supernatural being.I feel it is A)flat, but an not sure.

### Calculus urgent help

evaluate the limit as x approaches infinity for the absolute value of (the square root of xsquared+x) -x i think the answer is 1/2 from my calculator but I have to show how i got it algebricallly and have no clue what to do

### math 111 urgent please help

Find a degree 6 polynomial with - 8 as a root, no other roots, and in which the coefficient of x^6 is 16. Assume that all (non-constant) factors of the polynomial correspond to real zeroes.

### math question 2- very urgent !

Given f (x) = √(7 + x) + 4 . Use the rectangle method to approximate the area on the interval [0, 8] using 4 rectangles. (Assume the graph goes through the midpoint of each rectangle.)

### Calculus Need of Urgent Assistance

Let f(x) = x3 − 7x2. Find the point(s) on the graph of f where the tangent line is horizontal. (x, y) = I already got the smaller value, but I'm not getting the larger value right

### RE: Math Urgent

I posted this earlier but I think I phrased it in a confusing way Find g(x) + g(x) if g(x) = {(-4,5), (-2,-3), (0,5), (1,3), (3,-1), (5,5)} and g(x) = {(-3,-2), (-2,6), (-1,0), (1,0), (2,-6), (3,5), (4,0), (6,-2)}. I don't need the whole thing done i'm just very confused on ...

### English

I have an urgent question. I'm going to Australia for my holiday. I can speak English pretty well and i could practise it while I was there. (is it grammatically correct? Is the meaning that of a conditional clause? Thank you very much in advance

### Very Urgent Help Here (Math)

Area under y = -x^2 + 1 between x = 0 and x = 1 is rotated around x-axis. Find the volume by shell method. (Please solve it using step by step solution).

### Physics URGENT HELP

An athlete is training and is required to perform shuttle runs. From the starting position they sprint out to 10m (this takes 2 seconds). Where would the maximum acceleration occur? Justify your answer. Please help! Thankyou.

### Science ecosystems

Paper Glass Aluminum Wooden ruler Sand Steak Pork chops Salad Bread Hair Cotton fabric Wool Cheddar cheese Can you tell why ? It is urgent ! Are they. Biotic or abiotic

### Chemistry pretty urgent!!!!!!!

Chemical bonding question! The partial Lewis structure that follows (Figure 1) is for a hydrocarbon molecule. In the full Lewis structure, each carbon atom satisfies the octet rule, and there are no unshared electron pairs in the molecule. The carbon-carbon bonds are labeled 1...

### help PLEASE! URGENT!

ok, i need help w/ this problem. (4x^3 + x^2 + 3) + (x^3 + 2x^2 +1) can u please explain how to do this please? i'm very lost. Thanx! -Ally whoops, sorry i didn't mean to post twice! gather like terms.. (4x^3 + x^3)+(x^2 + 2x^2) +(3+1)....

### Urgent math

A man gets a job with a salary of $40,000 a year. He is promised a $1900 raise each subsequent year. Find his total earnings for a 10-year period.

### CHEMISTRY--PLEASE HELP, URGENT

A saturated solution of CaSO4(aq) is made in a beaker until there is excess calcium sulfate resting at the bottom. Then solid potassium sulfate is added. Which of the following is true? (The Ksp for potassium sulfate is larger than the Ksp for calcium sulfate) a. More calcium ...

### PLEASE VIEW- URGENT!

I do not understand this question. Could you please explain? "Beneatha is particularly bitter, but Ruth defends Walter. What does Ruth say?" (Act III, SceneI) For Further Reading * A Raisin in the Sun - SraJMcGin, Monday, September 3, 2007 at 7:36pm I remember answering this ...

### MATHS VERY URGENT :l

In each fruit hamper there were 7 oranges and 5 apples. 9 hampers were sold. How many pieces of fruit were sold together?

### algebra II-URGENT

the perimeter of a rectangular yard is 270 feet. If its length is 25 feet greater than its width what are the dimensions of the yard

### Physics URGENT!!!

A 91.0 kg fullback running east with a speed of 6.00 m/s is tackled by a 73.0 kg opponent running north with a speed of 3.00 m/s. Where did the lost energy go?

### Urgent help calculus

If the area in square units of the region under the curve of the function f(x)=5, on the interval from x=a to x=8 is 20 square units what is the value of a? 4 5 6 7 8

### GEOMETRY TANGENTS

Triangle ACE is a circumscribed triangle. Points B, D and F are the points of tangency. If AC= 16 and AE is 9 cm and CE = 15 cm . Find AD, FE and CD HELP PLEASE VERY URGENT

### linear algebra urgent

For the orthogonal matrix A = 1/sqrt(2) -1/sqrt(2) -1/(sqrt(2)) -1/sqrt(2) verify that (Ax,Ay)=(x,y) for any vectors x and y in R2. Can someone please explain this

### Technology

Which of the following is an example of a recent development in technology Need help urgent Please whats the answer and the right answer

### Math

Does Anyone have the answers to math unit 3 lesson 12 : Exponents factors and fractions unit test its urgent please

### Physics - urgent help needed

Explain using an example how to charge an object positively using only a negatively charged object.

### Precalculus(URGENT)

g(x)=1-5x if the domain of the function of g is {x-3 is less than or equal to x which is less than or equal to 2} what is the smallest value of the range show work please

### Trigenometry

VERY URGENT! PLEASE HELP SOLVE! tan(x)+1=sqrt(3)+sqrt(3)cot(x)as well as sin(2x)= 2 cos^(x) 4cos2(x) = 8sin(x)cos(X)

### SCIENCE Biology (urgent)

1.Do organisms benefit from being classified as a different species?How? 2.Importance of classifying organisms.. I;m not good in science...

### Urgent

draw an angle x in the 1st quadrant with sinx=3/5, and an angle y in the 2nd quadrant with cosy=-12/13, then determine the exact value of tan(x+y).

### VERY URGENT MATH(Formalizing Relations & Functions

What is the domain of the function below? {(0,2), (3,1), (5,2), (8,4)}? (1point) Is the following relation a function? {(0.3, 0.6), (0.4, 0.8), (0.3,0.7), (0.5,0.5)} (1point)

### ALGEBRA! URGENT. Check Answers!

1. 18x^2 + 6 + 4x - 15x^2 - 4 + 13x Answer: 3x^2 + 17x + 2 2. 3x^2 + 6 - 2x + 5x - 4x^2 + 9 Answer: -x^2 + 3x + 15 3. 3x^2 + 5x - 7x + 3 - 5x^2 + 2 Answer: -2x^2 + 2x + 5 4. In the expression -7x - 3x^2 + 5. What is the coefficient of x? Answer: I think it's 7 or -7 Thanks!

### Sign language

if you write with your left hand you are said to be left handed in asl which would be your non dominant hand? Urgent!!!

### Social Studies-URGENT

I'm doing a project for social studies, and I want to know if the African Queen Lily grows in Sudan. Please help!

### calculus!URGENT

Show that the tangent line to the curve y=x^3 at the point x=a also hits the curve at the point x=-2a. Any help?! PLEASE!

### geology please help me urgent if you can please

the question is below: explain the role of sedimentary rocks in the rocks cycle?

### Urgent Math

Let f"(x)=4x^3-2x and let f(x) have critical values -1, 0, and 1. Determine which critical values give a relative maximum. A)-1 B)0 C)1 D)-1 and 1 E) none of these

### Math. Urgent please help

ABC is an isosceles triangle. If AB =AC =16, BC=8. D is the midpoint of side AC , and G is the centroid of triangle ABC , find BD .

### Urgent Calc Help!!! Thanks!

Find the absolute maximum and absolute minimum values of f on the given interval. f(x) = xe^((−x^2)/98), [−6, 14]

### math-urgent

Sample space ={1,2,3,4,5} p(1)=0.1, p(2)=0.2 and p(3)=p(4)=0.05. Assume that A={1,3,5} and B={2,3,4}. Find p(5). Find p(A^c). I need help with this question. It is a probability question. please help.

### Math! URGENT

Describe the number of solutions for the equation. 5(x-9)=5x A. No solution B. One solution C. Infinite solutions Is the answer B? Thank You for any help.

### Math! URGENT

Describe the number of solutions for the equation. -2(x-1)=2x-2 A. Infinite solutions B. One solution C. No solution Is the answer B?

### Urgent ..!Math

If a car covers 82.5km in 5.5 liters of petrol, how much distance will it cover in 13.2 liters of petrol?

### Chemistry (urgent)

The gold foil Rutherford used in his scattering experiment had a thickness of approximately 4×10^−3 mm. If a single gold atom has a diameter of 2.9 x10^-8cm , how many atoms thick was Rutherford's foil? Express your answer using one significant figure. convert 4x10^-3mm...

### Chemistry URGENT

I have to match the items to the statements below, and I'm stuck! My answers are in parentheses, but I know that some of them are wrong. Please help if you know how...I would GREATLY appreciate it! A Dilute B Unsaturated C Saturated D Supersaturated 1. Sodium acetate solution ...

### Math ....urgent help

i just don't get this elimination method ..... plz help me plz.....teach me how to keep the x and y in a parallel line. and which number to multiply.....plz help -5x-4y=-11 10x=-6-y help me plz......

### chem urgent

Calculate the mass ( kg ) of the solute benzene and the mass ( kg ) of the solvent acetone that should be combined to generate 1.51 kg of a solution that is 0.275 m benzene.

### Pre-Algebra [urgent!]

I can't find the solution to this problem; can someone please show me how to solve it step-by-step? Solve the equation for y in terms of x: 1. -8x + 5y = 10 Thanks! -MC

### CALCULUS! PLEASE HELP URGENT!

Which of the following functions have a derivative at x=0? I. y= absolute value(x^3-3x^2) II y= square root(x^2+.01)- absolute value (x-1) III y= e^x/cosx

### Math (URGENT)

solve for x, 0 ¡Ü x < 360 tan2x+1=0 My answers: 22.5, 157.5, 202.5, 337.5 Textbook: 67.5, 157.5, 247.5, 337.5 I don't understand. Am I wrong? Thanks for your help.

### English

plz can any 1 give me an article on ''Coping/Dealing with loss'' or u can also give me a story on the same topic bt plz fast It's urgent

### Science 8A

Umm, can someone give me an example of a stable system? Also, how were you able to determine whether or not this system is stable? Please help! Urgent!

### Urgent math

so I tried to expand this question and I got x^3 *x2, i don't know if it's right but if not can I get a step by step explanation please, Expand (2x + y^2)^5. (Simplify your answer completely.)

### math-Urgent help please.

A diver's elevation is -30 feet relative to sea level. She dives down 12 feet. What is her elevation after the dive?

### Career Urgent

people i really need your help i don't know waht are the the negative things being a web designer/developer i thought for more than an hour and i still couldn't figure out what are the neagtive things please help and thank you

### Violence Action Plan (urgent)

Make a list of five or more different things students in school could do to prevent bullying? There's already anti-bullying day. So I don't know... 1.Guest Speaker maybe? 2. 3. 4. 5. Please help. Thank you.

### Pre-Cal(Urgent!!)

Find all the solutions of the equation in the interval (0,2pip) sin(x + pi/6) - sin(x -pi/6) = 1/2 I am only stuck on the last part. I have 2sinx(sqrt3/2) = 1/2 Does the 2 cancel out with the sqrt 3/2. I am not sure what to do.

### English

I have a last question.It's urgent. While I was getting ready for school, my mum made/was making breakfast for me. I think I should you the past continuous in both cases because the two actions are continuous.

### Math URGENT PLEASE

Please Help, The last question has to be done by midnight. A chevy Bel Air, a classic car today, cost $2,400.0 new in mid-1963. How much would that be in 2012 dollar.

### Calculus...URGENT..show steps please

Use implicit differentiation to find the points where the parabola defined by x^{2}-2xy+y^{2}-6x+2y+17 = 0 has horizontal and vertical tangent lines. List your answers as points in the form (a,b).

### Please help! Urgent

A homeowner installed a new swimming pool for $8500. He paid 8% down and then paid 36 monthly payments of $243.07. Determine the APR of the loan to the nearest one-half of a percent.

### maths

I don't know how to solve this question.urgent A one side open cylindrical drum has inner radius 28cm.and height 2.1m.How much water you can store in the drum.Express in litres.(1 litre=1000cc.)

### Urgent math

I eliminated 2 of the 5 and now I have 3 I am confused towards which is the right one? help mathematical induction to determine which formula is true for all natural numbers n ≥ 3 a) 2n2 > (n + 1)2 b) (n − 1)2 > n2 − 6 c) (n + 1)2 < n2 +

### Physics-Urgent

A sign with a mass of 23 kg is hanging in two wires both making an angle of 27 degrees with the vertical. Find the tension in one of the wires. Give your answer in newtons (N) and with 3 significant figures.

### history

hi... i need to know what the name of the native people of ecuador are called...and i also need a brief summary about them.. i need websites..and some information that u might know.. please help (urgent)...

### Honors Biology - URGENT!!!

Remember that the greater the concentration of hydrogen ions, the lower the pH of a solution. How do you suppose the pH of the solution in the thylakoid space compares with the pH of the solution in the stroma? What is responsible for the difference?