Wednesday

August 20, 2014

August 20, 2014

Number of results: 25,030

**Chemistry**

A solution of NaCl in water has a vapor pressure of 18.1 torr at 25 degrees C. What is the mole fraction of NaCl solute particles in this solution? What is vapor pressure at 45 degrees C? Vapor pressure of pure water is 23.8 torr at 25C and 71.9 torr at 45C, assume ions are Na...
*March 7, 2010 by Sara*

**Algebra II**

Find the solution if possible. If there is not enough information to solve the problem or if it has no solution, say so. If extra information is given, identify it. 14. A collection of 30 coins worth $5.50 consists of nickels, dimes, and quarters. There are twice as many dimes...
*August 24, 2008 by Emily*

**chemistry**

what is the chemical equation for these situations..? a) there is a straight iron nail in the solidified gelatin solution. the gelatin solution was prepared with phenolphthalein and K3Fe(CN)6. b) same scenario as with (a) but the nail is bent c) same with (a) but the nail has ...
*January 11, 2011 by princess*

**chemistry**

Use Henry's law and the solubilities given below to calculate the total volume of nitrogen and oxygen gas that should bubble out of 1.8 of water upon warming from 25degree C to 50degree C . Assume that the water is initially saturated with nitrogen and oxygen gas at 25degree C...
*January 24, 2010 by bf*

**Calculus**

True or false: If f(x) is continuous on the interval [a,b] & if the definite integral of f(x) over this interval has value zero, then the equation f(x)=0 has at least one solution in the interval [a,b]. True or false: If f(x) is continuous everywhere and F(x)= int from 0 to x ...
*January 25, 2012 by Kate*

**Chemistry**

A sample of benzoic acid contaminated with NaCl and sand is to be recrystallized: Benzoid Acid: Solubility in water at 100 degrees Celsius in g/100 mL = 6.8, at 0 degrees Celsius in g/100 mL = 0.2. NaCl: Solubility in water at 100 degrees Celsius in g/100 mL = 39.1, at 0 ...
*October 21, 2012 by Trisha*

**Algebra S.O.S**

I've been working on this a while, and I thought I got it right...until I got to step two. When I tried "veryfying my solution point" The lines didn't intersect at (4,2). I don't know, it's probably a silly little mistake on my part, but I can't get it quite right. The problem...
*February 11, 2009 by Katy*

**chemistry**

Adding a complex ion forming species to a solution will increase the solubility of a slightly soluble species. Calculate the Molar solubility (s) of AgI in a 1.75 M ammonia solution. The Ksp for AgI is 8.3 x 10-17 and the Kf for Ag(NH3)2+ is 1.5 x 107. I have tried getting ...
*April 14, 2014 by bekah*

**Statistics**

The average age of chemical engineers is 37 years with a standard deviation of 4 years. If an engineering firm employs 25 chemical engineers, find the probability that the average age of the group is greater than 38.2 years old. If this is the case, would it be safe to assume ...
*October 17, 2010 by Anonymous*

**Statistics**

Exercise 8.92 Tony's Pizza guarantees all pizza deliveries within 30 minutes of the placement of orders. An agency wants to estimate the proportion of all pizzas delivered within 30 minutes by Tony's. What is the most conservative estimate of the sample size that would limit ...
*November 23, 2013 by ----*

**chem**

1.) When determining the melting point it's described in my text as recording 2 points in the melting process. a) when the first drop of liquid is seen b) when all of the compound is liquified and since I have to determine the melting point of sulfanilamide pure and impure (I ...
*September 3, 2007 by ~christina~*

**mass media**

If you have a population of 500,000 people how many to be sample to give a representative profile with only a 5% point margin of error ?
*April 14, 2008 by leslie*

**Statistics Help Please**

A sample of eight observations of variables x and y is shown below: x 5 3 7 9 2 4 6 8 y 20 23 15 11 27 21 17 14 Find the value of coefficient of correlation, r. a) - 0.991 b)0.872 c)- 0.512 d)0.942
*March 29, 2009 by Stuart*

**Earth Science**

a sample of magma flows very quickly. Would you expect it to contain high or low amounts of silica? Why? please help
*September 20, 2009 by NeedHelpPlz*

**Chemistry**

What volume in mL of .100 M NaOH would be required to titrate a 297 mg sample of a weak acid with an equivalent weight of 126 grams?
*November 30, 2009 by Telly*

**statistics**

Number sampled is 1,000 and mean is 7.2 on a scale from 1-10 how do I determine standard deviation. Can we answer this with using the sampling distribution of the sample proportion?
*February 13, 2010 by mark*

**chemistry**

Determine the minimum volume of 6.40M HNO3 required to dissolve a 2.40g sample of Cu. 2NO3-(aq)+8H+(aq)+3Cu(s)-->2NO(g)+4H2)(l)+3Cu2+(aq)
*April 28, 2010 by Catalina*

**Statistics**

In a random sample of 50, the average is 3987 with a population standard deviation of 630. How can one find the 90% confidence interval of the true mean?
*October 26, 2010 by Tony*

**chemistry**

A 0.446 g- sample of an unknown monoprotic acid was titrated with 0.105 M KOH. the molar mass is 120 g/mol What is the pKa value?
*November 22, 2010 by james*

**chesmistry**

about how many skittlesium nuclei would remain after three half lives if the intial sample had 500 skittles?
*November 27, 2010 by alex*

**Chemistry**

Consider the titration of a 35.0-mL sample of 0.175 M HBr with 0.200 M KOH. Determine the pH after adding 5.0 mL of base beyond the equivalence point.
*February 27, 2011 by Brian*

**Chemistry**

A sample of a gas weighs 4.526g and has a volume of 890.9 mL at 645.0 torr and 29(degrees C). What is its molar mass? I just need help setting this up!
*March 30, 2011 by Toni Jones*

**statistics**

Use the margin of error E = $10, confidence level of 99%, and ó = $40 to find the minimum sample size needed to estimate an unknown population mean, .ì
*June 22, 2011 by Jessica*

**statistics**

How large a sample should be surveyed to estimate the true proportion of college students who do laundry once a week within 3% with 95% confidence?
*July 30, 2011 by Anonymous*

**statistics**

A biologisst reports a confidence interval of (3,7,5,5) when estimating the mean height ( incentimeters) Of a sample of seedlings. The estimated margin of errors is___
*August 11, 2011 by lulu*

**Chemistry**

A sample of Freon was found to contain 3.21 g of C, 19.0 g of Cl, and 10.2 g F. What is the empirical formula of this compound? C0.0352Cl0.0705F0.0705 C0.5ClF C2Cl4F4 CCl2F2 CClF
*October 1, 2011 by Anonymous*

**chemistry DONT spik **

a sample of carbon dioxide gas has a mass of 52.0g. how many oxygen atoms arr present?explain please don't skip
*October 2, 2011 by anu*

**statistics**

For a sample size of 10 from a population whose standard deviation is not known, which type of probability distribution is used to help calculate a confidence interval for the mean?
*April 11, 2012 by Anonymous*

**chemistry**

A 445 g sample of ice at –58oC is heated until its temperature reaches –29oC. Find the change in heat content of the system.
*September 10, 2012 by Calorimetry problem*

**Chemistry**

After 1.78 years, 1.990 g of a radioisotope remains from a sample that had an original mass of 2.000 g. Calculate the half-life of the isotope.
*September 16, 2012 by Rachel*

**Statistics**

What critical t value would be needed to construct a 90% confidence interval on a sample of size 22? 1.717 1.323 2.080 1.321 1.721
*October 26, 2012 by Clueless*

**Statistics**

What critical t value would be needed to construct a 90% confidence interval on a sample of size 22? 1.717 1.323 2.080 1.321 1.721
*November 1, 2012 by Clueless*

**Stats**

What critical t value would be needed to construct a 90% confidence interval on a sample of size 22? 1.717 1.323 2.080 1.321 1.721
*November 4, 2012 by etwetw*

**Chemistry**

The half-life of hafnium-156 is 0.025 s. how long will it take a 560 g sample to decay to one-fourth it's original mass?
*December 11, 2012 by Jacob *

**chemistry**

what pressure would have to be applied to a 27.2 ml sample of gas at 25 Celcius and 1.00atm to compress its volume to 1.ooml without a change in temperature
*February 23, 2013 by Gerry*

**physics**

A 445 g sample of ice at -58CENTIGRADE iS HEated until its temparature reaches -29 centigrade.find the change in heat contend of the system.
*March 7, 2013 by anjana*

**chemistry**

What is the specific heat of an unknown substance if a 2.31 g sample releases 12.5 cal as its temperature changes from 24.9°C to 20.7°C? Please explain ans show steps.
*April 16, 2013 by Julia*

**Math/Statistics**

A and B are events defined on a sample space, with the given probabilities. Find P(A and B). (Give your answer correct to two decimal places.) P(A | B) = 0.43 and P(B) = 0.75
*May 29, 2013 by Nora*

**science**

A 24.3g sample of a compoud XO2 contains 3.365 x 10^23 oxygen atoms. Determine the molar mass in g/mol of the element X. Show your work.
*August 18, 2013 by Adalaide *

**Chemistry**

A 24.3g sample of a compound XO2 contains 3.365 x 10^23 oxygen atoms. Determine the molar mass in g/mol of the element X. Show your work.
*August 18, 2013 by Adalaide *

**math/chem**

If aluminum foil has a density of 2.70 g/ml, then how thick would be a 2.22 g sample of foilif it measures 5.0 cm on each side. PLEASE SHOW WORK THX!
*September 27, 2013 by john*

**Calculus**

Romat 421 (a fictitious substance) decays by about 1.5% every day. How much of a 80 pound sample remains after 5days?
*October 23, 2013 by Migena*

**chemistry**

A 0.286g sample of carbon dioxide, CO2, has a volume of 585mL and a pressure of 495mmHg . What is the temperature, in kelvins and degrees Celsius, of the gas?
*October 23, 2013 by rose*

**chemistry**

A 0.286g sample of carbon dioxide, CO2, has a volume of 585mL and a pressure of 495mmHg . What is the temperature, in kelvins and degrees Celsius, of the gas?
*October 24, 2013 by ellie*

**statistics**

A psychologist studied self esteem scores and found the sample data set to be normally distributed with a mean of 50 and a standard deviation of 5?
*January 25, 2014 by Stephanie*

**Chemistry**

what would be a possible reason for the melting point of a purified sample to be the same as the literature value in a synthesis of salicyclic acid lab??
*January 26, 2014 by Angela*

**AP Chemistry**

To what temperature must a sample of helium gas be cooled from 110 degrees C to reduce its volume from 4.9 L to 0.7 L at constant pressure? Answer in units of K
*February 16, 2014 by Gabriella*

**AP Chemistry**

A 2.8 gram sample of a gaseous substance occupies 12 L at 47 degrees C and 683 torr. What is the density of the gas under these conditions? Answer in units of g/L
*February 16, 2014 by Gabriella*

**Chemistry**

If the titration of a 25.0 mL sample of calcium hydroxide requires 34.45 mL of 0.100 M perchloric acid, what is the molarity of the base? 2 HClO4(aq) + Ca(OH)2(aq) → Ca(ClO4)2(aq) + 2 H2O(l)
*April 12, 2014 by John Cook*

**Calculus**

Poli 761 (a fictitious substance) decays by about 7% every day. How much of a 88 pound sample remains after 9 days?
*May 6, 2014 by Ann*

**chem**

A sample of carbon dioxide with a mass of 0.91 g was placed in a 335 mL container at 363 K. What is the pressure exerted by the gas? Answer in units of atm
*May 30, 2014 by reis*

**chemistry**

Consider the equation 2kclo3(s) -> 2kcl(s)-1302(g). 3.00-g sample kclo2 is decomposed and the oxygen at 24.0 and 0.982 its either, 911, 304, or 608
*June 10, 2014 by kaitlin*

**statistics**

The following random sample was collected: 22 33 44 6. The 80% confidence interval for the mean is? I have the answers; however, I do not know how to plug in the numbers to solve the problem.
*June 21, 2014 by Nicole*

**Science**

Hello, I am working on Methylene Blue dye adsorption for my thesis. I am embarassed to say I don't know basic chemistry. Anyway, my question is I have Methylene Blue Trihyrate 95%. I am trying to prepare stock solution. If I plan to make 1000 mg/l of solution, Is it as simple ...
*November 19, 2007 by Sinduri*

**Science**

If I want to make a solution that has a 5% concentration of salt, is it correct for me to have 380mL water and 20g salt? My method behind this was that I wanted a 400g solution, and so since 1mL water is equal to 1g water, I did: 400x0.95=380g water or 380mL water and 400x0.05...
*February 6, 2011 by Anonymous*

**Inorganic Chemistry**

Which aqeuous solution has a freezing point closest to that of 0.30M C12H22O11? A) 0.075M AlCl3 B) 0.15M CuCl2 C) 0.30M NaCl D) 0.60M C6H12O6 I know the answer but I don't know the reason or rationale behind it. Please explain. I suggest you review Raoult's Law at http://...
*August 5, 2007 by Vic*

**Chemistry**

To a beaker containing 200 mL of a solution of CuSO4 was added 10.0g of magnesium metal. When the reaction was complete, a mixture of Mg and Cu having a mass of 14.50g remained in the beaker. Calculate the molarity of the original CuSO4 solution. I understand that I need to ...
*February 17, 2012 by Kay*

**Statistics **

Prospective Cohort Study The following tables show the crude and sex-specific results from a Prospective Cohort Study that examines the association between a binary exposure (E) and the development of a disease (D) during 20 years of follow-up. Use these data to solve the ...
*January 15, 2013 by netspirit*

**chemistry**

the experiment is a sequence of Chemical Reactions. Procedure part A preparation fo copper (II) Hydroxide-get a solution of copper(II)nitrate. measure 25ml of solution. to blue solution add 2mL of concertarted NaOH while stirring. Let mixture settle and use litmus paper to ...
*September 15, 2010 by Missy *

**Chemistry**

Complete the following table for aqueous solutions of caffeine, C8H10O2N4. a) molality b) mass percent solvent c) Ppm solute All we're given is Mole fraction solvent= .900. How do I solve for the other parts with only this?? It XH2O = 0.9, then Xcaffeine=0.1. Suppose we have 0...
*March 20, 2007 by Chris*

**confused**

as i earlier posted and , 1 day ago , i am confusesd hw we ll find freezing point......isnt it T pure solvent - T solution .. which ll be 0-(-23.3) = 23.3 plz conform .. and do we have to use Kf.m .. formula in order to get ( -23.3)(1)= -23.3 .. as someone earlier posted plz ...
*January 25, 2009 by Dr Bob plz conform*

**chemistry**

Two new metallic elements have been discovered, Cimium (Ci) and Sadowium (Sd). Both the pure elements and their solutions form simple cubic lattices. The bond strengths of the Ci-Ci and Sd-Sd bonds are known, but not the Ci-Sd bond. Bond Bond Energy (kJ/mole) Ci-Ci -245 Sd-Sd...
*November 12, 2013 by Harold*

**Chemistry**

Two new metallic elements have been discovered, Cimium (Ci) and Sadowium (Sd). Both the pure elements and their solutions form simple cubic lattices. The bond strengths of the Ci-Ci and Sd-Sd bonds are known, but not the Ci-Sd bond. Bond Bond Energy (kJ/mole) Ci-Ci -245 Sd-Sd...
*November 15, 2013 by HelpMePLSSS*

**Chemistry**

Two new metallic elements have been discovered, Cimium (Ci) and Sadowium (Sd). Both the pure elements and their solutions form simple cubic lattices. The bond strengths of the Ci-Ci and Sd-Sd bonds are known, but not the Ci-Sd bond. Bond Bond Energy (kJ/mole) Ci-Ci -245 Sd-Sd...
*November 16, 2013 by youlifex*

**Math**

5).Hat size are determined by the measuring the circumference of the head in either inches or centimeters. Use ratio and proportion to complete the following table. Hat size Head circumference Head Circumference 7 ½ to nearest 1/5 inch to the nearest centimeter 7 3/8 23 3/5 60...
*May 28, 2010 by Mickey*

**Chemistry**

Please show work. 2Al(s) + 2NaOH(aq) + 6H2O(l) ---> 2NaAl(OH)4(aq) + 3H2(g) What mass of hydrogen gas would be formed from a reaction of 2.48 g Al and 4.76 g NaOH in water? Pb(NO3)2(s) + 2NaI(aq) ----> 2PbI2(s) +2NaNo3(aq) (a) If the solution contains 7.00 g NaI, what ...
*February 25, 2013 by Anonymous*

**Chem**

A student was performing an extraction procedure of o-Xylene from water into octanol. The total mass of o-Xylene was 0.10 gram (molecular weight 106.2 g/mole). The volume of water was 990mL and volume of octanol 10 mL. There is a head space of 200 mL above the solution and it ...
*July 31, 2013 by Sahara*

**chemistry**

calcium nitrate + sulfuric acid =caso4+? write a balanced chemical equation for this reaction including states. Ca(NO3)2 + H2SO4 ==> CaSO4 + 2HNO3 You don't have enough information to provide states. CaSO4 will be a solid so you write CaSO4(s). H2SO4 will be (l) if it is ...
*July 30, 2007 by walter*

**Differential Equations**

a) Sketch the phase line for the differential equation dy/dt=1/((y-2)(y+1)) and discuss the behavior of the solution with initial condition y(0)=1/2 b) Apply analytic techniques to the initial-value problem dy/dt=1/((y-2)(y+1))), y(0)=1/2 and compare your results with your ...
*February 3, 2013 by Erica*

**Math**

-x^3 + 1.85x^2 - x +0.15 = 0 how can you solve for x? An exact solution or a numerical solution? Exact solutions can be obtained as follows: x^3 - 1.85x^2 + x - 0.15 = 0 First get rid of the quadratic term by substituting: x = (y + 1.85/3) You then obtain an equation of the ...
*July 10, 2007 by JV*

**Chemistry**

1) it is found that .30 M solutions of the three shots Na3X, Na2Y and NaZ have pH's of 8.5, 7.0 and 10.5 not necessarily in order. (X,Y, and Z AE anions. Na is sodium ion) A) explain how anions can act as bases in aqueous solution. Write a chemical equation to explain your ...
*April 6, 2014 by Reggie*

**Biochemistry**

Urea is heated in a test tube. A condensation reaction occurs. Which one? What is the formula for this reaction? Then cupper sulphate and sodium hydroxide is added to the tube. This is compared to a tube in which cupper sulphate, sodium hydroxide and a solution of egg white ...
*December 25, 2008 by Ian*

**chemistry**

Write the equation for the reaction, if any, that occurs when each of the following experiments is performed under standard conditions. a) crystals of iodine are added to an aqueous solution of potassium bromide. b) liquid bromine is added to an aqueous solution of sodium ...
*May 13, 2007 by Krystal*

**PLEASE HELP ME! PLEASE!**

1 )3x + 8y = 1 7x + 4y = 17 Answer: (3,1) 2) -3x + 5y = -7 9x + 2y = 38 Answer: (4,1) 3) 7r + 3s = 13 14r - 15s = -16 Answer: (1,2) 4) 2x - 7y = 42 4x - 14y = 64 Answer: No Solution ?? 5) 9x + 12y = 15 3x + 4y = 5 Answer: Identity ?? 6) 2 = 4s - 3t 2 = 12s - 9t Answer: No ...
*February 25, 2009 by Veronica*

**Chemistry**

Three of the primary components of air are carbon dixode, nitrogen, and oxygen. In a sample containing a mixutre of only these gases at exactly one atmosphere pressure, the partial pressure of carbon dixoide and nitrogen are given as Pco2 = 0.285torr and Pn2=593.525torr. What ...
*March 25, 2009 by Chopsticks*

**statistics**

In response to media inquiries and concerns expressed by groups opposed to violence, the president of a university with over 25,000 students has agreed to survey a simply random sample of her students to find out whether the student body thinks the school’s “Plundering Pirate...
*July 31, 2009 by Bryant*

**Biology Chemistry Part**

I'm trying to calculated the rate of reaction In this lab I took a 50 mL beaker and poured in 10 ml of cold distilled water into it, I then poured in 30 ml of original enzyme solution (I believed we used cold potato juice or something), I then took a piece of paper and placed ...
*September 26, 2010 by Kate*

**Math-Help Please**

Can someone help me figure this out? 1. Find the first and third quartiles, Q1 and Q3 of the following numbers: 347,242,146,391,249,567,277,218,319 and 0.16,0.08,0.27,0.20,0.22,0.32,0.25,0.18,0.28,0.27 2. Which of the following numbers are integers? 75,9.82,-1/14,-498,0.71 The...
*March 5, 2007 by Denim*

**chem**

Use Henry's law and the solubilities given below to calculate the total volume of nitrogen and oxygen gas that should bubble out of 1.2L of water upon warming from 25C to 50C . Assume that the water is initially saturated with nitrogen and oxygen gas at 25C and a total ...
*January 25, 2010 by rc*

**chemistry-molarity**

Say I have 50 mL of bromocresol green indicator. This solution has 80mg/L. the molar mass is 698 g/mol. Then say I took 10 mL of that solution and dilute it with .4 M HCI. I want to find the concentration/molarity of bromocresol green. This is what I have attempted to do: 10ml...
*August 2, 2010 by Anonymous*

**Engineering **

The angular velocity of a rigid body rotating about an axis of rotation is w = 5^i + 2^j - 4^k rad. per. sec. Determine the linear velocity of point B on the body with a position vector r = 3^i - ^j + 3^k ft. directed from a point on the axis of rotation. Would the solution ...
*February 12, 2012 by Aaron*

**Science**

1. What is molarity of products? I can't decide if it's a. The concentration of the reactants measured in mol/L of solution or b. The concentration of the products measured in mol/L of solution 4. How does pressure relate to reaction rates? I'm stuck between a. Pressure is ...
*May 7, 2013 by mysterychicken*

**Science**

1. What is molarity of products? I can't decide if it's a. The concentration of the reactants measured in mol/L of solution or b. The concentration of the products measured in mol/L of solution 4. How does pressure relate to reaction rates? I'm stuck between a. Pressure is ...
*May 9, 2013 by mysterychicen*

**physiology**

Is the following statement True or False, and Why? The presence of a hyperosmotic solution in the duodenum will stimulate gastric emptying. True; this helps to speed up the absorption process True; the hyperosmotic solution draws contents in from the stomach False; this causes...
*April 26, 2010 by Anna*

**BioChem**

I have a hard time with this question. Please help. One way to determine the concentration of protein in a solution is to perform a "protein assay". There are several assay kits on the market that one can use, but they all rely on the common paradigm that the aromatic amino ...
*June 17, 2006 by Jamshid*

**Chemistry - titration lab**

Hello. For my chemistry of solutions class, we had a titration lab where we titrated NaOH into an HCl + H2O mix. This was a preparatory titration for the next one consisting of the hydrolysis of ethyl acetate into acetic acid with H+ ions as a catalyst (in our case the HCl). ...
*July 31, 2012 by Robertq*

**Chemistry**

Calculate the freezing point depression and osmotic pressure at 25 degrees C of an aqueous solution of 1.0 g/L of a protein (mol wt= 90,000) if the density of the solution is 1.0 g/mL. I know how to calculate freezing point depression and osmotic pressure, but I'm having ...
*March 24, 2007 by Jessica*

**Statistics**

For all of the following use the five step process to solve the problem in the question, that is, state the null hypothesis, the alternative hypothesis, the level of significance and the type of test (z-test, t-test, p-value, confidence limit and whether it is two tailed, one-...
*November 11, 2011 by Kristi*

**Chemistry**

The quantity of antimony in an ore can be determined by an oxidation-reduction titration with an oxidizing agent. The ore is dissolved in hot, concentrated acid and passed over a reducing agent so that all the antimony is in the form Sb3 (aq). The Sb3 (aq) is completely ...
*December 2, 2012 by Anon*

**Chemistry**

The quantity of antimony in an ore can be determined by an oxidation-reduction titration with an oxidizing agent. The ore is dissolved in hot, concentrated acid and passed over a reducing agent so that all the antimony is in the form Sb3 (aq). The Sb3 (aq) is completely ...
*December 3, 2012 by Anon*

**Chemistry**

A student was given 100mL of HCL solution in a 250mL beaker and told that the HCL was 0.11M. The student was also given phenolphthalein indicator and 250 ML of 0.1234 M NaOH. The student first filled a buret with NaOH solution. The student then placed an appropriate volume of ...
*November 21, 2013 by Lenny*

**HCl - Chem**

Assume you had a very magnified view of a solution of HCl that allowed you to "see" the HCl. Draw this magnified view. If you dropped in a piece of magnesium, the magnesium would disappear and hydrogen gas would be released. Draw this out using symbols to represent the ...
*January 13, 2007 by Gil*

**Science**

Ms. Lewis is a chemist mixing two solutions together. A chemical reaction takes place, and the solution becomes warm. Which statement best describes what has happened? A. Energy has been created in the form of thermal energy B. Energy has been transformed from one form to ...
*February 2, 2013 by Anne*

**STATS**

1-Suppose that the fuel comsumption of cars for the same model is normally distributed. A random sample of ten new cars of the same model are randomly selected and their fuel consumption (l/100 km) is determined by subjecting them to a road test of 500 km. Their mean fuel ...
*April 1, 2010 by Judy and group*

**chemistry**

If you have a solution that is 1.7 M sodium chloride and you have 1 L of that solution, how many moles of sodium chloride do you have?
*October 28, 2011 by emily*

**Chemsitry**

The Ksp of PbBr2 is 6.60× 10^–6. What is the molar solubility of PbBr2 in pure water? What is the molar solubility of PbBr2 in 0.500 M KBr solution? What is the molar solubility of PbBr2 in a 0.500 M Pb(NO3)2 solution?
*March 17, 2013 by Anon*

**Physical Science**

1. What is molarity of products? I can't decide if it's a. The concentration of the reactants measured in mol/L of solution or b. The concentration of the products measured in mol/L of solution 4. How does pressure relate to reaction rates? I'm stuck between a. Pressure is ...
*May 6, 2013 by mysterychicken*

**Physical Science**

1. What is molarity of products? I can't decide if it's a. The concentration of the reactants measured in mol/L of solution or b. The concentration of the products measured in mol/L of solution 4. How does pressure relate to reaction rates? I'm stuck between a. Pressure is ...
*May 6, 2013 by mysterychicken*

**Please help with Chemistry?????**

5.00 mL of 2.00x10^-3M Fe(NO3)3 is mixed with 4.03 mL of 2.00x10^-3M NaSCN and 1.08 mL of 0.1M HNO3, for a total volume of 10.11 mL. a) What is the initial concentration of the Fe(NO3)3 in the mixed solution? b) What is the initial concentration of the NaSCN in the mixed ...
*February 26, 2014 by Dan*

**chemistry**

1. Nitrogen gas and sodium liquid are produced by the decomposition of sodium azide NaN3 (s). what volume of nitrogen gas, measured at 25 C and 0.980 atm, is produced by the decomposition of 62.5 g of sodium azide? 2. A gas sample in a container with a volume “V” at a ...
*December 9, 2010 by Helen*

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