Number of results: 62,603
math
85/x=80/100 (i got 80 because it was 100%-20%) 85*100 = 80*x 8500=80x divide both sides by 80 x = $106.25
Sunday, October 30, 2011 at 7:59pm by Millie
Math Reading Problem
1 hammock = 100 fish = 100(30/20 coconuts = 100(30/12)(50/20 bananas = 625 bananas
Tuesday, November 27, 2007 at 11:51pm by Reiny
physics
On the first, calculate the time it takes for something to drop 5.24m, then subtract that time from the total time. depth lake=vf*time You can calculate vf from vf^2=2g h and calculate time to surface..5.24=1/2gt^2
Monday, September 7, 2009 at 7:27pm by bobpursley
chemistry
It would help if you told us what was confusing you. You have two equations. Balance them. 2WS3 + 9O2 ==> 2WO3 + 6SO2 2WO3 ==> 2W + 3O2 Here is the procedure for working stoichiometry problems. This will work all of them for you so print this out and save it. 1. ...
Tuesday, November 15, 2011 at 2:55pm by DrBob222
Chemistry
I think you are confused. The problem, as you posted it, is to determine the theoretical yield starting with a 1.5 g sample. So the problem wants to know, in grams, how much of the C7H7Br is formed IF it is 100% yield. Give me a few minutes and I'll work the problem and ...
Sunday, August 30, 2009 at 7:47pm by DrBob222
economics
Suppose that the following equations describe an economy (C, I, G, T, and Y are measured in billions of dollars and r is measured in percent; for example, r = 10 C=170+0.6(Y-T),T=200,I=100-4r,G=350 (M/P)d=L=0.75Y-6r, (M/P)s=735 a. Derive the equation for the IS curve (Hint: ...
Monday, August 16, 2010 at 11:07pm by yaw
Chemistry
I have a problem that has been driving me crazy trying to solve, and I was wondering if someone could help. The problem is this: "Given the reaction: CuSO4 + 4 NH3 ----> Cu(NH3)4SO4, if 10 grams of CuSO4 reacts with 30 grams of NH3, what is the theoretical yield of...
Thursday, August 23, 2007 at 9:29pm by Josh
math need help
Sorry, this is an "annuity due" problem, where the payments are made in advance. $100 paid quarterly in advance for 2 1/2 years at 11% interest. n=10 quarters R=1+0.11/4=1.0275 (compounded quarterly) Future value = $100*(R+R²+...R^n) = $100*R*(1+R+....+R^(n-...
Saturday, April 30, 2011 at 6:16pm by MathMate
college Chemistry
1. If 25 grams of Iron (III) hydroxide is dissolved in a 500mL volumetric flask, what is the Molarity of the solution? please only one problem to a post. They get too long when you have more than 1. moles = grams/molar mass. You have grams and molar mass, solve for moles. M = ...
Saturday, December 4, 2010 at 5:46pm by DrBob222
Finance
Butler Corp paid a dividend today of $3.50 per share. The dividend is expected to grow at a constant rate of 8% per year. If Butler Corp stock is selling for $75.60 per share, the stockholders' expected rate of return is:
Sunday, July 1, 2012 at 10:00pm by Anonymous
chem
How many grams of NH4Cl must be added to 0.560 L of 1.90 M NH3 solution to yield a buffer solution with a pH of 8.50? Assume no volume change. Kb for NH3 = 1.8 10-5. i am confused as how to find the grams?
Tuesday, March 19, 2013 at 7:59pm by hannah
chemistry
I have to find the theoretical yield of acetylsalicylic acid in the exeriment? I used 5.0 mL acetic anhydride which is about 5.40 grams. When I calculated the theoretical yield, I got 9.53 grams. Is this number correct?
Wednesday, April 4, 2012 at 3:08pm by casey
Chemistry
When 1 gram of sex hormone (contains C, H, and O) was burned in a combustion analysis, 1.5 grams of CO2 and 0.405 grams of H2O were obtained. The molar mass was found to be 352g/mol. What is the molecular formula for the sex hormone?
Monday, June 20, 2011 at 2:56pm by IVY
chem
How many grams of glucose should we dissolve in one liter of water to get one molar solution (1M). This is the exact question given to me by my cell bio teacher. anything will help. MW of glucose is 180 grams.
Wednesday, January 19, 2011 at 6:53pm by nicole
physics
The energy given off by 300 grams of an alloy as it cools through 50°C raises the temperature of 300 grams of water from 30°C to 40°C. The specific heat of the alloy (in cal/g C ) is: i know Q=CpM(delta T) but what is what?
Monday, June 22, 2009 at 5:15pm by jane
Chemistry
can someone check my answers thank you. 1)How many grams of hydrochloric acid are required to react completely with 4.30 grams of zinc? answer: 0.1328 g H2 2)How many molecules of gas will be produced? answer: 0.395x10^23 molecules
Thursday, January 10, 2008 at 5:23am by Mike
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 ...
Thursday, April 1, 2010 at 4:41am by Judy and group
math
If the question is "What percentage of x is y", then you would just divide x by y and multiply by 100 (y/x*100). So for instance, here we just put the numbers in and get 7.7*10^9/2.58*10^12= 0.002984496124031007751937984496124 multiply that by 100 and get: 0....
Saturday, March 8, 2008 at 11:23am by Jack
chemistry
Use PV = nRT to calculate n, number of moles H2 gas. Don't forget to change 1670 psi to atmospheres and temperature to Kelvin. Use 1 L for volume. Convert n to mass (moles = grams/molar mass). Then use mass = volume x density to determine density.
Tuesday, November 3, 2009 at 9:24am by DrBob222
chemistry
Pentaborane-9(B5H9) IS a colorless highly reactive liquid that will burst into flames when exposed to oxygen.The reaction is ' 2B5H9(l)+ 12O2--> 5B2O2(s)+9H2O(l) Calculate the kilojoules of heat released per gram of the compound reacted with oxygen.The standard ...
Wednesday, November 2, 2011 at 7:58pm by asembi
Algebra 2
An orange grower finds that she gets an average yield of 40 bushels per tree when she plants 20 trees on an acre of ground. Each time she adds a tree to an acre, the yield per tree decreases by 1 bushel, due to congestion. How many trees per acre should she plant for maximum ...
Wednesday, January 18, 2012 at 12:46am by Peter
Algebra 1
Candy worth $2.45 per pound is mixed with candy worth $2.30 per pound.How much of each kind of candy must be used to have 30 pounds of a mixture worth $2.35 per pound?
Tuesday, June 28, 2011 at 6:20pm by Bella
math
ee ann wants to mix tea with 2 Cents per oz with 100oz of tea worth 5 cents per oz to make a mixture worth 3 cents per oz. how much 2 cent tea should be used?
Wednesday, January 19, 2011 at 2:36pm by Anonymous
chemistry
A 20 gram piece of metal is added to a sample of 100 grams of water inside a calorimeter. If the metal is at a temperature of 125° Celsius and the water is at 20° Celsius, which of the following best describes what will occur inside the calorimeter?
Friday, July 29, 2011 at 8:09pm by Amanda
finance
Butler Corp paid a dividend of $3.50 per share. The dividend is expected to grow at a constant rate of 8% per year. If Butler Corp. Is selling for $75.60 per share, the stockholders' expected rate of return is _________
Monday, May 16, 2011 at 2:05am by Anonymous
Chemistry
a solution is made by combining 10.0 ml of 17.5 M acetic acid with 5.54 g of sodium acetate and diluting to a total volume of 1.50 L. a)calculate the pH of the solution. b) how many grams and milliliters of 14.6 M potassium hydroxide needs to be added so pH=pKa? c)what is the ...
Tuesday, November 29, 2011 at 5:09pm by Amanda
Chemistry
in this experiment you are you will begin by preparing a dilute soultion of sodium hydroxide by taking 50 ml of 3 M NaOh stock solution and diluting it with 250 ml of water. i found that and the answer was .5 but how do i do this b. calculate the number of moles and grams of ...
Tuesday, February 23, 2010 at 9:48pm by Chris
science
1 mol Fe for every 2 mol HBr. 55.85grams fe per 161.816 g hbr. 3.2 grams fe x(161.816g hbr/55.85g fe)=9.27g fe
Sunday, February 14, 2010 at 2:37pm by Anonymous
chemistry
To dilute a solution just remember that mL1 x M1 = mL2 x M2 For solids. First you need to know how much solution you want to prepare. Let's say you want to prepare 1000 mL of 0.05M NaOH. Then you want how many moles? That will be M x L = 0.05 x 1 = 0.05 moles. Then moles...
Wednesday, May 4, 2011 at 12:01pm by DrBob222
Computer programming
I'll give you a headstart: Input: input fat_grams; input calories; Validate: - Make sure the number of fat grams and calories are not less than 0. - the number of calories cannot exceed fat grams X 9. Calculations: - Percentage of calories from fat = (fat grams x 9) / ...
Monday, April 4, 2011 at 8:48pm by MathMate
Math
A car rental agency charges $120 per week plus $.12 per mile driven. How many miles did you drive if the total charge is $162?
Thursday, February 21, 2013 at 8:54pm by Anonymous
Math help
A car rental agency charges $120 per week plus $.12 per mile driven. How many miles did you drive if the total charge is $162?
Sunday, February 8, 2009 at 4:52pm by Anonymous
Math help
A car rental agency charges $120 per week plus $.12 per mile driven. How many miles did you drive if the total charge is $162?
Sunday, February 8, 2009 at 4:52pm by Anonymous
groundwater science
True or false: dimensions for Q can be, for example, cubic feet per minute, being distinguished from units for Q, which are length cubed per unit time.
Saturday, February 5, 2011 at 6:05pm by luke
chemistry
On a trip you travel 308km in 3.5h and use 32l of gasoline. A)What is your average speed in kn per hour? B)What is your gas mileage in miles per gallon?
Friday, January 28, 2011 at 1:30pm by Twynna
chemistry
On a trip you travel 308km in 3.5h and use 32L of gasoline. A) What is your average speed in km per hour? B)What is your gas mileage in miles per gallon?
Wednesday, January 26, 2011 at 11:52am by Twynna
Chem
125 what per day? 1.10 what per liter (euros, U. S. dollars, Italian Lira, French Franc, UK pound?) gas mileage is 39.0 what?
Monday, February 1, 2010 at 9:16pm by DrBob222
MTH 157
The 99 employees in a factoryearn a salary of $35,000 per year, while the CEO makes $266,000 annually. What are the mean, median salaries for all 100 people? Is the mean or median the more appropriate measure of "center" in this case? Explain.
Tuesday, January 18, 2011 at 8:32pm by Lo
Chemistry (geometric)
Calculate the number of cations anions, and formula units per cell unit of the following : rock-salt structure, and flourite....I have no idea how to do the second one but for the first one I got 13, 14, and 13.5 respectively. Also, what are the coordination numbers of the ...
Sunday, October 24, 2010 at 11:13pm by Sarah
Nice unanswered question by Maggie
"100 bushels of corn are divided among 100 men, women, and children. Men receive 3 bushels each, women 2 bushels and children 1/2 bushel each. How can the bushels be distributed? is there more than one solution? if so, find the other solutions." let the number of men...
Wednesday, September 16, 2009 at 8:45am by Reiny
math
how do i change 3.75 into a fraction simple or improper fraction? you could say 3 and 3/4 (since .75 = 3/4) or you could go from there and convert to improper. basically simplify 375/100 (multiply 3.75/1.00 by 100/100) but it can't be 3 and 3/4 your answer should be 15/4 ...
Sunday, April 15, 2007 at 9:27pm by jasmine20
Chemistry
2.914-2.304 = loss in mass = mass H2O lost. %H2O = (mass H2O/mass sample)*100 = ? Note: A more interesting problem is to calculate the formula of the hydrated CaSO4 from these data.
Monday, September 24, 2012 at 10:47pm by DrBob222
chemistry
A student breaks a thermometer and spills most of the mercury (Hg) onto the floor of a laboratory that measures 15.2 m long, 6.6 m wide, and 2.4 m high. (a) Calculate the mass of mercury vapor (in grams) in the room at 20 degrees celcius. The vapor pressure of mercury at 20 ...
Wednesday, September 21, 2011 at 10:17am by Amber
AP chem
A 0.345g sample of anhydrous BeC2O4, which contains an inert impurity, was dissolved in a sufficient water to produce 100ml of solution. A 20.0ml portion of the solution was titrated w/ KMnO4(aq). The balanced equation for the reaction that occurred is as follows: 16H^+(aq) + ...
Thursday, January 4, 2007 at 7:48pm by michelle
Chemistry(Please help)
What is the molar solubility of barium phosphate in a 0.282M barium acetate solution? If I set up and ice table I would have 0.282M - X = ? Would I use the molar mass of barium acetate to complete the equation to find X? Ba3(PO4)2 ==> 3Ba^2+ + 2PO4^3- Ba(C2H3O2)2 ==&...
Saturday, April 28, 2012 at 5:02pm by Hannah
math
the same cereal costs $3.99 per box at one store, $3.25 at another store and $3.59 per box at the third store what is the average price per box of cereal? solve using an algebra form. I know how to get the answer but what algebreic form would i use? 3x=1083 x=$3.61 I don't...
Monday, November 7, 2011 at 9:30pm by jill
Stoichiometry problem
I'm stuck and am hoping you can help. Here is the problem: You react 7.92 grams of silver nitrate, AgNO3(aq), with an excess of sodium chloride, NaCl(aq). How many grams of silver chloride, AgCl(s), will precipitate from the solution? Any help would be appreciated. Most of...
Saturday, September 9, 2006 at 10:04pm by Rachel
Chemistry
For the equation: deltaHrxn = qrxn / mol substance to calculate deltaH per mole what does the mol substance mean? Does this mean that you use the mm of the substance or if you already calculated the # of moles of a substance do you use that?
Monday, February 13, 2012 at 8:00pm by Hannah
Math
The formula and the logic are explained in my answer. Each day one watch gets 2.5 seconds ahead of the other. You have to calculate how many days it takes for the difference to equal 12 hours. Divide 12 hours (in seconds) by 2.5 seconds per day.
Saturday, November 10, 2007 at 12:13pm by drwls
Chemistry
microwave ovens work by irradiating food with microwaves, which is absorbed by the water molecules in the food and is converted into heat. Assuming that microwave ovens emit radiation with a wavelength of 12.2cm, calculate how many photons are emitted per second in a 1000-Watt...
Monday, November 5, 2012 at 12:16am by Kez
Chemistry
If 20.0 grams of propane are burned with 50.0 grams of oxygen: What mass of CO₂ is produced? What mass of water is produced? What mass of which reactant was excess? Thank you so much.
Sunday, October 23, 2011 at 6:06pm by Mom
Chemistry
If 20.0 grams of propane are burned with 50.0 grams of oxygen: What mass of CO₂ is produced? What mass of water is produced? What mass of which reactant was excess? Thank you so much.
Sunday, October 23, 2011 at 6:02pm by Mom
Chemistry
If 20.0 grams of propane are burned with 50.0 grams of oxygen: What mass of CO₂ is produced? What mass of water is produced? What mass of which reactant was excess? Thank you so much.
Sunday, October 23, 2011 at 5:45pm by Mom
Chemistry(Please help, thank you)
For the equation: deltaHrxn = qrxn / mol substance to calculate deltaH per mole what does the mol substance mean? Does this mean that you use the mm of the substance or if you already calculated the # of moles of a substance do you use that?
Monday, February 13, 2012 at 9:31pm by Hannah
chemistry
calculate the number of millimoles in the original 12.3 x 33 mmoles the final volume is 513 ml so the concentration (moles per litre) is 12.3 x 33 mmoles/513 ml
Monday, November 29, 2010 at 5:16am by Dr Russ
finance
For mark: interest rate = 7.5% p.a. = 7.5%/12 per period of one month = .625% Future value of $5000 in n years, FVK(n) = 5000*(1.00625)12*n For Madonna, interest rate = 8.125% p.a. = 8.125%/4 per quarter = 2.03125% per quarter Future value of $5000 in n years, FVD(n) = 5000*(1...
Sunday, October 25, 2009 at 1:58pm by MathMate
Algebra
Substitute the 100 degrees F 100=9/5C+32 subtract 32 from each side 100-32=9/5C 68=9/5C 68x5/9=C so C=37.8 Is this OK. Can you see where you went wrong?
Monday, February 11, 2008 at 10:50am by Dr Russ
Math
log( 8x/(1+√x) = 2 8x/(1+√x) = 100 8x = 100 + 100√x 8x - 100 = 100√x square both sides 64x^2 - 1600x + 10000 = 10000x 64x^2 - 11600x + 10 000 = 0 x = (11600 ± √132000000)/128 = 180.384 or .8662 since we squared we must ...
Sunday, November 21, 2010 at 10:33pm by Reiny
AP tatistics
Formula: CI95 = mean ± 1.96(sd/√n) Your data: mean = 5.62 sd = 2.50 n = 100 Substitute the values into the formula and calculate the interval. You should then be able to select the correct answer.
Sunday, April 21, 2013 at 7:22pm by MathGuru
Physics
Two water jets are emerging from a vessel at a height of 50 centimeters and 100 centimeters. If their horizontal velocities at the point of ejection are 1 meter/second and 0.5 meters/second respectively, calculate the ratio of their horizontal distances of impact.
Wednesday, February 22, 2012 at 12:09pm by Lauren01
physics
How to calculate the potential energy in a CR circuit with a resistor and 10micro-farrad capacitor before the switch is closed. the capacitor has a charge of 100 v and two seconds after the switch is closed looses 37% of its original value.
Sunday, February 5, 2012 at 3:41pm by jonathan
Business Maths
Please how do i calculate this problem and enter it in a journal entry: If a company issues 10-year, 8%, $100,000 bonds paying interest on an annual basis, at a $5,200 premium, the annual interest expense on the bonds will be:
Friday, January 8, 2010 at 5:38pm by Peaches
Chemistry - Chemical Kinetics
1) if the concentrations of trace constituients of the atmosphere are expressed in molecules/cm3 , what would be the units of reaction rate???? i think the ans is molecules/cm3 per seconds since the usual units of reaction rate is mol per dm3 per seconds.....am i correct?
Sunday, January 30, 2011 at 8:45pm by Davia
chemistry
Technically, none of the answers listed are correct. I expect the intent of the problem is to answer with 5.85. But here is how you do it (and you transposed the numbers in your math but otherwise you math is good). 100 mmoles x (1 mole/1000 mmols) x (58.44 g/m) = 5.84 grams ...
Thursday, February 4, 2010 at 9:41pm by DrBob222
finance
Should We Purchase That New Copier? Campus Print Shop is thinking of purchasing a new, modern copier that automatically collates pages. The machine would cost $22,000 cash. A service contract on the machine, considered a must because of its complexity, would be an additional $...
Tuesday, September 25, 2007 at 9:52am by joe
Physics
The speed of the transverse wave is V = (frequency) x (wavelength) = 100.8 m/s V = sqrt(T/sigma) where T is the tension (240 N) and sigma is the mass per unit length. Solve for sigma and use it to compute the length. Length = (Mass)/(sigma)
Monday, January 14, 2013 at 4:45am by drwls
math115
If you used the following formula to calculate the quartiles, the answers are correct. There are different ways to calculate quartiles. One that is widely used is to calculate the location of the sorted list, given by: i=(1/4)*(n+1) where n is the number of observations. ...
Wednesday, October 14, 2009 at 12:47pm by MathMate
calculus
the demand for a certain type of auto tire is given by x=f(p) 50(1+e^-p/60). a)if the weekly quantity demanded is 60000 tires find the price? b)if the current price is $120 per tire and is increasing at a rate of $2 per week, what is the rate of change of the demand per week? ...
Saturday, April 20, 2013 at 9:15pm by anonymous
chemistry
Let's see if you can do that in your head, knowing that 4.18 joules is 1 calorie. (a good number to remember) 80 joules is therefore very close to 20 calories. Since the specific heat of water is 1.0 calories per degree-gram, 20 calories is enough to heat 2 grams 10 ...
Friday, December 31, 2010 at 12:02pm by drwls
chem
Consider the titration of 20 mL of .105M Butric Acid HBut, with .125M sodium Hydroxide? calculate the pH before titration calculate the volume of added base to reach the end point calculate the pH halfway to the equivalence point kb(But-)= 6.6x 10^-10 and ka(HBut)= 1.5x 10^-5 ...
Monday, March 1, 2010 at 11:38pm by simi
statistics
sat scores around the nation tend to have a mean score of about 500, a standard deviation of 100 points and are approximately normal distribution. a person who score 600 on the sat has approximately what percentile rank within the population? show all calculations. 600-500/100...
Saturday, October 16, 2010 at 12:27pm by mary
Chemistry
No, it's the same concept as %ionization for acids. Set up an ICE chart for NH3 ..........NH3 + H2O ==> NH4^+ + OH^- initial...1.0M..........0........0 change.....-x............x........x equil.....1-x............x........x Then calculate OH^- and % ionization = (OH...
Wednesday, March 7, 2012 at 12:26am by DrBob222
chemistry
Please help me with this question. Give the formula for calcium phosphate and then answer the following questions: (a)Calculate the percent composition of each of the elements in this compound. (b)If you knew that there was 50.0g of phosphorus in your sample,how many grams of ...
Thursday, April 22, 2010 at 9:29pm by Kim
chemistry
The usual buret used is 50.0 mL. The reading error is about 0.02 mL. So if you make a reading error of 0.02 mL in 10 mL that is an error of (0.02/10)*100 = 0.2% or 2 parts/1000. If you make the same reading error in 40 mL it is (0.02/40)*100 = 0.05% or 0.5 parts/1000 which is ...
Sunday, March 20, 2011 at 6:29pm by DrBob222
Chemistry
I would change the dimensions to cm, then h x w x l = volume in cc. That many cc will be that many grams H2O. Then q = mass H2O in grams x specific heat H2O in J/g (or cal/g) x (Tfinal-Tinitial).
Wednesday, March 27, 2013 at 10:12pm by DrBob222
oceanography
14C has a half-life of 5,730 years. If we start with 70 grams of 14C at time zero how many grams of 14C will be left after three half-lives?
Monday, October 15, 2012 at 3:27pm by teal
chemistry
Write the equation and balance it. mols H2 = grams/molar mass mols O2 = grams/molar mass Convert mols H2 to mols product. Do the same for O2. The smaller number of mols wins; that will be the mols H2O produced. Then mol x molar mass H2O = grams H2O.
Monday, February 18, 2013 at 11:10pm by DrBob222
earth science
what would be the chart to use for carbon 14 whcih has a half life of 5730 years and a piece of wood which originally has 12 grams pf radioactive isotope; If the half lives occurred and now has 0.75 grams left?
Thursday, November 29, 2012 at 3:46pm by lan
Chemistry
if 225 mLs of .50 molars of hydrofloric (HF) acid solution is reacted with 25.5 grams of solid zinc what is the most (in grams) aqueous zinc flouride that would be produced? Based on this, how much nonlimiting ractants will be left over?
Monday, March 14, 2011 at 8:43pm by Nicole
college maths
One and one-half cups of native blueberries have 232 calories. How many calories does one cup of native blueberries have? (Points: 5) 233.5 calories per cup 232 calories per cup 154.7 calories per cup 0.006 Calories per cup Not sre how to calclate this one can i get some help ...
Wednesday, December 15, 2010 at 2:16pm by lisa
statistics
A construction zone on Kings Road has a posted speed of 45 kilometers per hour. The speeds of vehicle passing through this construction zone are normally distributed with a mean of 46 kilometers per hour and a standard deviation of 4 kilometers per hour. Find the percentage ...
Friday, May 11, 2012 at 12:53am by Nesa
Chemistry
This is one type of stoichiometry problem; all of this kind are worked the same way. Write the equation and balance it. You have that. Convert 0.94 (if that is the starting material) to moles. moles = grams/molar mass Using the coefficients in the balanced equation, convert ...
Sunday, February 28, 2010 at 6:38pm by DrBob222
Chemistry
Can't you calculate the limiting reagent. Starting with 6 mols B, how many mols A would you need for 100% reaction? That would be 6 mols B x (4 mols A/1 mol B) = 24 mols A and you don't have that much A; therefore, A must be the limiting reagent. Just to check that, ...
Wednesday, October 8, 2008 at 5:17am by DrBob222
5th grade math
Like many people, I do not like fractions. Decimals are much easier. 273/252 = 1.083333 = 1 83/100. Since no number goes evenly into both 83 and 100 -- 1 83/100 is the simplified answer.
Wednesday, September 9, 2009 at 4:49pm by Ms. Sue
Chemistry
No you need not go through that. The easy way is to determine the H2O lost (as in the previous problem), convert that to grams BaCl2.2H2O, then subtract the mass of BaCl2.2H2O from the total mass to find mass K2SO4. Then %K2SO4 = (mass K2SO4/mass sample)*100 = ?
Wednesday, September 28, 2011 at 2:43pm by DrBob222
chemistry
100 million automobiles contains 1.1 kg of CFC-12 and leaks 25% of its CFC-12(CF2Cl2) into the atmosphere per year, how much Chlorine in kilograms is added to the atmosphere each year due to auto air conditioners?
Monday, June 28, 2010 at 7:23am by jeff
chemistry
You mean AgCl instead of NaCl. Calculate moles AgC2H3O2. moles = M x L. Do the same for MgCl2. Look at how the moles combine and convert to moles AgCl. One of the reagent will be the limiting reagent unless you have stoichiometric amounts present. Then convert moles AgCl to ...
Sunday, February 28, 2010 at 8:55pm by DrBob222
AP chemistry
You have the equation. Convert 15.0 g NaNO3 to moles. #moles = grams/molar mass. Convert moles NaNO3 to moles NaN3 using the coefficients in the balanced equation. Convert moles NaN3 to grams by grams = moles x molar mass Post your work if you get stuck.
Tuesday, September 15, 2009 at 8:12pm by DrBob222
chemistry
1. Check your equation. I think you've made a typo. Fe2CrO4?? FeCrO4 perhaps? Then make sure the equation is balanced. 2. Convert 44 g CO2 to moles. moles = grams/molar mass. 3. Using the coefficients in the balanced equation, convert moles CO2 to moles of what you want. 4...
Monday, January 25, 2010 at 4:31pm by DrBob222
trigonometry math
Make a sketch His compass direction is your horizontal line with length of 100 At the end draw a vertical line upwards, (the wind direction from the south), label it y draw in your hypotenuse h , his/hers actual course . the angle is 20° for speed of wind tan 20° = y/...
Friday, January 4, 2013 at 8:54am by Reiny
Chem
moles ethylene clycol = grams/molar mass. Solve for mole. molality = moles/kg solvent Solve for molality delta T = Kf*m and convert to freezing point. delta T = Kb*m and add to 100 C to convert to boiling point.
Tuesday, March 22, 2011 at 6:53pm by DrBob222
science/ chemistry
Over 80 000 vehicles per day pass the site and the traffic is frequently congested. The surrounding area is described as forming a street canyon. The temperature at the site had reached 25 °C by 08:00, when the ethane concentration was recorded as 7.09 ppbv. This is ...
Sunday, September 14, 2008 at 4:36pm by Nicolas
Chemistry
Write and balance the equation. 2NaOH + H2SO4 ==> Na2SO4 + 2H2O How many mols of NaOH do you have? That's mol = grams/molar mass = 69.3/40 = about 1.73 From the equation, use the coefficients to convert mols NaOH to mols H2SO4. Thats 1.73 mol NaOH x (1 mol H2SO4/2 ...
Wednesday, October 24, 2012 at 6:05pm by DrBob222
chemistry
What is the rate of disappearance of dinitrogen pentoxide between 100 s and 200 s? Is this rate higher or lower than the rate from 0 s to 100 s that you calculated in part c? As the reaction takes place, what happens to [N2O5]? In general, does a higher concentration of ...
Thursday, April 26, 2012 at 5:14pm by Anonymous
chemistry stoichiometry
My chem teacher gave us this problem Twelve-gauge copper wire,like the kind commonly used in residential electrical systems, is roughly cylindrical and has a diameter of approximately .1040in. Copper's density is 8.92g/cubic cm and copper atoms have an approximate atomic ...
Sunday, September 9, 2007 at 9:34pm by Julissa
Chemistry
I will do an experiment that includes 4 grams of aluminum hydroxide and iron (III) oxide mixture, where 75% of it is Al(OH)3, and 15 ml of water and 25 ml of 2M KOH will be added and then boiled so that the Al(OH)3 dissolves. It will be filtered and then sulfuric acid will be ...
Sunday, March 25, 2012 at 3:28pm by Tiffany
chemistry
A chemistry student weighs out 0.172 grams of acrylic acid (HCH2CHCO2) into a volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.1800 moles/liter NaOH solution. Calculate the volume of NaOH solution the student will need to add ...
Wednesday, January 25, 2012 at 6:54pm by Lucas
chemistry
2 C2H2 + 5O2 >>> 4CO2 + 2H2O In the above equation . How many grams of CO2 are produced when 109.2 grams of C2H2
Wednesday, October 6, 2010 at 11:04pm by Steve
chemistry
Convert 11.5 gallons to mL. 1 gallon = 3.785 L. Convert that to mL, then mass in grams = volume x density Then convert grams to kg.
Saturday, September 8, 2012 at 3:16pm by DrBob222
chemistry
20 oz bottle of what? Here is a worked example but first convert 20 oz of whatever it is to grams. 1 oz = about 28.3 grams.
Monday, December 12, 2011 at 8:20am by DrBob222
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