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December 22, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
How many milliliters of a substance with a specific gravity of 0.88 would be needed to have 0.75 pounds of it?
Wednesday, October 1, 2014 at 6:49pm

Chemistry/Math
convert 0.01403 grams to ppm please show all step
Wednesday, October 1, 2014 at 6:07pm

chemistry
state the separation technique for silver choride and sodium trioxonitrate
Wednesday, October 1, 2014 at 5:14pm

Chemistry
A solution contains Cr3+ ion and Mg2+ ion. The addition of 1.00 L of 1.55M NaF solution is required to cause the complete precipitation of these ions as CrF3(s) and MgF2(s). The total mass of the precipitate is 49.9g .Find the mass of Cr3+ in the original solution.
Wednesday, October 1, 2014 at 4:58pm

chemistry
A solution is prepared by placing 23.9 g of KCl in a 0.500 L volumetric flask and adding water to dissolve the solid, then filling the flask to the mark. What is the molarity of an AgNO3 solution if 27.9 mL of the KCl solution react exactly with 45.0 mL of the AgNO3 solution?
Wednesday, October 1, 2014 at 3:00pm

chemistry
a system consisting of 1.5 mol CO2(g), initially at 15deg and 10 atm and confined to a cylinder of cross-section 10.0 cm2. it is allowed to expand adibatically against an external pressure of 1.0 atm until the piston has moved through 20 cm. assume that carbon dioxide may be ...
Wednesday, October 1, 2014 at 2:52pm

Chemistry
-Describe the zero sum rule -True of False: The formula for the nitride ion is N^(-3) -True of False: The stock system shows the charge on the negative ion
Wednesday, October 1, 2014 at 1:14am

chemistry
A 30 ml sample of unknown strong base is neutralized after the addition of 12 ml of a 0.150 M HNO3 solution if the unknown base concentration is 0.0300 M give some possible identities for the unknown base
Wednesday, October 1, 2014 at 12:40am

chemistry
10 ml sample of vinegar an aqueous solution 0f acetic acid( HC2H3O2) is titrated with 0.5062 M and 16.58 ml is required to reach equivalence point what is the molarity of the acetic acid b. if the density of vinegar is 1.006 g/cm3 what is the mass percent of acetic acid of ...
Tuesday, September 30, 2014 at 11:03pm

Chemistry
If you are given a photoelctronic spectrum with just the peaks, how do you identify the element that would produce it?
Tuesday, September 30, 2014 at 10:22pm

solution making/ chemistry/biotech
how much of a .2M solution can you make with 340 g of calcium carbonate ( MW=100.0869) Do I multiply 340g by 1mole/MW
Tuesday, September 30, 2014 at 10:02pm

Chemistry
Silicon carbide, commonly known as carborundum, is a very hard and abrasive substance. The compound is prepared by heating silicon dioxide in the presence of graphitic carbon: SiO2(s) + 2C(s) --> SiC(s) + CO2(g) How many grams of silicon carbide can be formed from 20.0 g of...
Tuesday, September 30, 2014 at 9:50pm

chemistry
Naturally occurring silicon exists as 3 isotopes: 28Si, 29Si, and 30Si, whose atomic masses are 27.9769, 28.9865, and 29.9838, respectively. The most abundant isotope is 28Si, which accounts for 92.23% of naturally occurring silicon. Given that the average atomic mass of ...
Tuesday, September 30, 2014 at 9:45pm

Chemistry
How many grams of solid silver nitrate would you need to prepare 240.0mL of a 0.160M AgNO3 solution?
Tuesday, September 30, 2014 at 8:06pm

chemistry
Complete and balance each of the following equations. K2SO4(aq)+BaBr2(aq)→ Would it be K2SO4(aq)+BaBr2(aq)→K2Br2 +SO4Ba? Express your answer as a chemical equation. Enter no reaction if no precipitate is formed. (How can we know if a solid is formed in the product?)
Tuesday, September 30, 2014 at 7:42pm

chemistry
A solution contains an unknown amount of dissolved magnesium. Addition of 5.34×10−2mol of Na2CO3 causes complete precipitation of all of the magnesium. What mass of magnesium was dissolved in the solution.
Tuesday, September 30, 2014 at 7:19pm

Chemistry
HELP PLEASE. I have no idea how to set this up. I tried using the q=mc(change in temp) equation but its not working out. A 59.8 g block of an unknown metal at 87.5 degrees Celsius was dropped into an insulated vesssel containing approximately 33 g of ice and 23 g of water at 0...
Tuesday, September 30, 2014 at 7:00pm

chemistry
Calculate the air concentration (mol/l) of phenol in equilibrium with solution including 100 g/m3 of phenol.(T=25 C)
Tuesday, September 30, 2014 at 6:47pm

college chemistry
a 1.0kg sample of metal with a specific heat of 0.50KJ/Kg C is heated to 100.0C and then placed in a 50.0g sample of water at 20.0C . What is the final temperature of the metal and the water?
Tuesday, September 30, 2014 at 5:31pm

Chemistry
An aqueous stock solution is 85.0% H2SO4 by mass and its density is 1.83 g/mL. What volume of this solution is required to make 1.00 L of 1.35 mol/L H2SO4(aq)? Give your answer in millilitres, accurate to three significant figures.
Tuesday, September 30, 2014 at 4:27pm

Chemistry
Identify the following chemical equations by type. 1. If an electric discharge produces 800 cm3 of ozone (O3), how many cm3 of oxygen (O2) are required? 3O2(g) ---> 2O3(g) 2. When 75.0 dm3 of O2 react with an excess of glucose (C6H12O2), according to the reaction below, ...
Tuesday, September 30, 2014 at 3:05pm

chemistry 101
Give the name of the product from complete hydrogenation of 2-ethyl-1-hexene
Tuesday, September 30, 2014 at 1:42pm

Chemistry
How many grams of HCl are produced if the following reaction yielded 27.1 grams of H3PO4? PCl5 + 4 H2O --> H3PO4 + 5 HCl
Tuesday, September 30, 2014 at 1:22pm

chemistry
Household bleach contains (NaClO)2 that decomposes in water, NaClO + h2o = Na+ + OH- + Cl2 + O2 If 15ml bleach containing 5.85℅ NaClO is allowed to decomposes completely, then hoe many mL of o2 at 22C and 755mmHg can be liberated. Density of bleach= 1.12g/ml Answer I ...
Tuesday, September 30, 2014 at 1:10pm

Chemistry
Chemistry question: Given: CH4 + 2O2 ~ CO2 + 2H2O C - H = 99 kcal O - O = 119 kcal C = O = 192 kcal O - H = 111 kcal Calculate the change in energy for the CH4 - O2 system.
Tuesday, September 30, 2014 at 9:13am

Chemistry
Accurately weigh 0.9-1.1 g into a 200 mL beaker. Dissolve the KIO3 in a small amount of distilled water. Quantitatively transfer, with rinsing, to a 500 mL volumetric flask. Dilute to the calibration mark and shake well. Rinse the buret several times with small portions of the...
Tuesday, September 30, 2014 at 9:02am

chemistry
50g of watermelts at 0 degrees .what is the change in entropy of the water
Tuesday, September 30, 2014 at 6:55am

Chemistry 30
A mixture of 2.5 moles of H2O and 100 g of C are placed in a 50.0 L container and allowed to come to equilibrium in the following reaction: C(s) + H2O(g)  CO(g) + H2(g) The equilibrium concentration of hydrogen gas is found to be 0.040 M. What is the ...
Tuesday, September 30, 2014 at 1:21am

Chemistry 30
Consider the following reaction at equilibrium: 4NH3(g) + 5O2(g) ↔ 4NO(g) + 6H2O(g) In what direction will the following changes force the reaction? a) Addition of O2 b) Reduction of the amount of water vapour c) Increase in the pressure d) Decrease in the volume e) If ...
Tuesday, September 30, 2014 at 1:19am

PLEASE CHECK! ELA
Which word group is a complete sentence? A- Almost all the swimmers following the rules. B- Never had any interesting activities. C- After Chris finished chemistry experiment. D- Only two of the chairs matched the table. My guess is D.
Monday, September 29, 2014 at 10:32pm

Chemistry- Answer Check
In an ideal gas, if only one molecule in a thousand has enough energy to react, how can all molecules in a reactor be consumed? My answer: when the one molecule reacts, it causes the other molecules to gain energy. Is this right? I'm still confused on the question
Monday, September 29, 2014 at 10:03pm

Chemistry
A solution contains 5.6g of solute in 16 cm cubed of water. When the solution is cooled, crystals begin to appear at 11 degrees celsius. What is the solubility of the solute at 11 degrees celsius?
Monday, September 29, 2014 at 9:19pm

chemistry
The density of silver is 1.050×104 kg/m3. What is the mass of a rectangular ingot of silver with dimensions 1.00 cm × 4.00 cm × 0.780 dm? How do I get started? I really do not understand.
Monday, September 29, 2014 at 7:48pm

Chemistry
we would build one spectrometer apparatus with webcam to analyze two different beers based on yeast or bitterness so which one would be easy/less time to analyze yeast or bitterness ? please expalin why :S
Monday, September 29, 2014 at 6:50pm

Chemistry - Titrations
What volume (mL) of 0.2650 N H3PO4 is required to neutralize: a) 35.25 mL of 0.2300 M KOH b) 19.14 mL of 0.2300 M NH4OH Unfortunately, the teacher didn't get the opportunity to teach us titrations in class today, but this problem (and more) are still due by 11 pm tonight (...
Monday, September 29, 2014 at 6:02pm

Chemistry: Please check my answer
ClO2 is sometimes used as a chlorinating agent for water treatment. Cl2 + 4 NaClO -> 4 NaCl + 2 ClO2 In an experiment, 1L Cl2 measured at 10C and 4.66atm is dissolved in .75L of 2.00M NaClO. If 25.9g of pure ClO2 is obtained, then what is the percent yeild for this ...
Monday, September 29, 2014 at 4:59pm

Chemistry
Al and Fe react with HCl to produce a chloride salt and hydrogen gas. A .1924g sample of a mixture of Al and Fe is treated with excess HCl solution. A volume of 159mL h2 gas is collected over water at 19C and 841 torr. What is the mass percent by mass of Fe in the mixture? The...
Monday, September 29, 2014 at 2:21pm

chemistry
A mixture of 3.00 g of silver and copper metals was dissolved in excess nitric acid. Resulting salts, silver(I) nitrate and copper(II) nitrate, were isolated and dissolved in enough water to make 0.100 L of a solution with a total concentration of the nitrate ion equal to 0....
Monday, September 29, 2014 at 11:42am

chemistry
Identify each of the ff reactions and say wha type of diving force for this.(a) chlorine+sodium iodin=2sodium chloride+iodin
Monday, September 29, 2014 at 11:01am

Organic Chemistry
A 0.160 M solution of an enantiomerically pure chiral compound D has an observed rotation of 0.20° in a 1-dm sample container. The molar mass of the compound is 128.0 g/mol. (a) What is the specific rotation of D? (b) What is the observed rotation if this solution is mixed...
Monday, September 29, 2014 at 10:13am

chemistry
A 36.1 mL sample of oxygen gas contains 0.529 mol of oxygen. If enough oxygen is added to the sample to obtain a volume of 50.5 mL, what must the final mass of the sample be? (The pressure and temperature is constant.)
Monday, September 29, 2014 at 3:02am

Chemistry II
Dr.Bob222 please help given the following table of thermodynamic data substance delta HofF S PCl3 -288.07 kJ/mol 311.7 J/mol-k PCl3 -319.6 kJ/mol 217 J/mol- k determine the normal boiling point (C)of PCl3
Monday, September 29, 2014 at 1:43am

Chemistry
What is the difference between Citric Acid C6H8O7 and H3C6H5O7? I am seeing both and don't know which is the right one. Is one a solution of citric acid? Thanks
Monday, September 29, 2014 at 1:02am

Chemistry
15.0 mL of 0.30 M sodium phosphate solution reacts with 20.0 mL of 0.23M lead(II) nitrate solution. What mass of precipitate will form?
Sunday, September 28, 2014 at 11:59pm

Chemistry
A 55.29-g sample of Ba(OH)2 is dissolved in enough water to make 1.20 L of solution. How many milliliters of this solution must be diluted with water in order to make 1.00 L of 0.100 M Ba(OH)2? (Ignore significant figures for this problem.)
Sunday, September 28, 2014 at 11:58pm

Chemistry
During recrystallization, an orange solution of a compound in hot alcohol was treated with activated carbon and then filtered through fluted paper. On cooling, the filtrate gave gray crystals, although the compound was reported to be colorless. Explain why the crystals were ...
Sunday, September 28, 2014 at 9:41pm

Chemistry
a 6 g sample of magnesium was burned in a crucible producing 10 g of magnesium oxide. What mass of oxygen reacted with magnesium to form the 10 g of magnesium oxide?
Sunday, September 28, 2014 at 9:10pm

chemistry
What volume of a 0.550 M solution of potassium hydroxide can be made with 18.3 g of potassium hydroxide? (Ignore significant figures for this problem.)
Sunday, September 28, 2014 at 9:04pm

Chemistry
What mass of ammonium nitrate is require to produce 145L of N2O at 2850 torr and 42 degree celcius
Sunday, September 28, 2014 at 7:34pm

chemistry
What is the molar concentration of all ions present in a solution prepared by mixing the following? Assume that volumes of the solutions are additive, and neglect H+ and OH- from water. 60.0 mL of 0.25 M KCl and 80.0 mL of 0.85 M NaOH.
Sunday, September 28, 2014 at 5:23pm

Chemistry
Aluminum sulfate reacts with calcium hydroxide (from lime) to form aluminum hydroxide and calcium sulfate. Write the balanced formula unit equation for the reaction.
Sunday, September 28, 2014 at 5:10pm

Chemistry
What is the mass of 3.01 x 10^22 iron (II) ions, Fe^2+?
Sunday, September 28, 2014 at 5:03pm

Chemistry
A .7178 g sample of a hydrocarbon occupies a volume of 390.7 mL at 65C and 99.2kpa. When the sample is burned in excess oxygen, 2.4267 g CO2 and .4967g H2O are obtained. What is the molecular formula of the hydrocarbon? Write a plausible structural formula for the molecule. ...
Sunday, September 28, 2014 at 3:51pm

chemistry
If He(g) has an average kinetic energy of 7590 J/mol under certain conditions, what is the root mean square speed of F2(g) molecules under the same conditions?
Sunday, September 28, 2014 at 3:47pm

chemistry
how many moles of oxygen are there in 50.0 grams of KClO3? Given: 50.0 g KClO3 Find: ? mol O K= 39.10 g/mol Cl= 35.45 g/mol O= (16.00)x3= 48.00 g/mol Total: 122.55 g/mol KClO3 50.0 g KClO3 x 1 mol KClO3/122.55 g/mol KClO3=0.408 mol KClO3 0.408 mol KClO3 x 3(oxygen)=1.22 moles O
Sunday, September 28, 2014 at 3:36pm

chemistry
A sample of unknown metal has a mass of 36.7 g. This metal was placed in boiling water at 96.0oC until the metal had reached the temperature of the water. The metal was then placed in a foam cup with 50.0 g of water in it at 20.0oC. The cup absorbs 42.0 J/oC, and the ...
Sunday, September 28, 2014 at 2:46pm

chemistry
Use Hess's Law and a table of heats of formation to determine the enthalpy for the following reaction. 3SO2(g) + 3H2O(g) + 3/2O2(g) --->3H2SO4(l) ΔH = ?
Sunday, September 28, 2014 at 2:32pm

chemistry
Use Hess's Law and a table of heats of formation to determine the enthalpy for the following reaction. 3SO2(g) + 3H2O(g) + 3/2O2(g) --->3H2SO4(l) ΔH = ?
Sunday, September 28, 2014 at 2:21pm

chemistry
heat lost by metal + heat gained by water = 0 [mass metal x specific heat metal x (Tfinal-Tinitial)] + [mass water x specific heat water x (Tfinal-Tinitial)] = 0 Substitute and solve for specific heat metal.
Sunday, September 28, 2014 at 2:16pm

chemistry
21.90 kJ/g x 0.1182 g = ?q = energy obtained by combusting salicylic acid. Then calculate the heat capacity of the calorimeter. That is q from above = C/degree c x 2.84 and solve for C, the heat capacity of the calorimeter. q = heat capacity x delta T q = Cfrom above x 3.50 ...
Sunday, September 28, 2014 at 2:15pm

chemistry
Balance following oxidation reduction reactions using oxidation states method? a) Cl2(g) + Al(s) --> Al3+(aq) + Cl- b.) O2(g) + H2O(l) + Pb(s) --> Pb(OH)2(s) c) H+(aq) + MnO4-(aq) + Fe2+(aq) --> Mn2+(aq) + Fe3+(aq) + H2O(l)
Sunday, September 28, 2014 at 12:55pm

Chemistry
2. The half-life of a radioactive element is important when considering its application in medicine. For example, iodine-131 is often used in the imaging of the thyroid. The reason is that iodine is readily absorbed by the thyroid gland. Another reason is the short half-life ...
Sunday, September 28, 2014 at 12:31pm

chemistry
A sample of gas occupies 17mL at -112 degrees Celsius. Assuming the pressure is held constant, what volume does the sample occupy at 70 degrees Celsius?
Sunday, September 28, 2014 at 12:03pm

Chemistry
Use half-cells to balance the following redox reaction, and label the oxidation and reduction half-reactions. Also, note that bromide is a spectator ion and can be eliminated. FeBr(aq) +Mg(s) = Fe(s) + MgBr2(aq) Fe^+2 -2e +Br^- e+ + Mg^+2 -2e =Fe^+2 -2e +MgBr2(aq) -2e e+ Idk ...
Sunday, September 28, 2014 at 11:32am

Chemistry
GE's light bulb division ordered 100.kg of tungsten for the filaments. If the tungsten comes in a cube what is the volume of the cube? What is the length of each side?
Sunday, September 28, 2014 at 8:43am

chemistry
The structure of tryptophan is shown at the right along with the pK values of the α-carboxyl and α-amino groups. (pK1=2.38; pK2=9.39) Tryptophan is a diprotic acid which can exist in three protonated forms: H2A , HA0, and A–. (HA0 consists primarily of the ...
Sunday, September 28, 2014 at 8:32am

chemistry
I what this question to be solve.what will be the pressure of 50cm^3 of oxygen gas in a piston initially at a pressure of 2atm when the volume was 500cm^3 at a steady temperature of 300k
Sunday, September 28, 2014 at 8:01am

Chemistry- colligative properties
Which of the following aqueous solution of equal molality has the lowest freezing point? a. H2SO3 b. NaCl c. NaOH d. Ca(NO3)2 How do you answer this without looking at their i values from textbooks? I know that delta(Fpt) = m * K,f * i and that i is approximately equal to the ...
Sunday, September 28, 2014 at 6:08am

Chemistry
A Power plant rated at 800 MegaWatts generates steam at 585 K and discards heat to a river at 295 K. If thermal efficiency of plant is 70% of maximum value, how much heat is discarded to river at rated power? Please help with steps on how to solve this one.
Sunday, September 28, 2014 at 6:03am

chemistry
If He(g) has an average kinetic energy of 7590 J/mol under certain conditions, what is the root mean square speed of F2(g) molecules under the same conditions?
Sunday, September 28, 2014 at 3:43am

chemistry
The complete combustion of salicylic acid releases 21.90 kJ of energy per gram of salicylic acid. In a particular bomb calorimeter (initially at room temperature), the combustion of 0.1182 g of salicylic acid, in the presence of excess oxygen, causes the temperature of the ...
Saturday, September 27, 2014 at 10:00pm

chemistry
Hydrogen gas produced by this reaction is typically collected via water displacement, during which time the hydrogen gas becomes saturated with water vapor. If 238.4 mL of gas with a total pressure 1.27 atm was collected via water displacement at 29.4 °C, what is the ...
Saturday, September 27, 2014 at 9:55pm

chemistry
30 ml of sample of unknown strong base is neutralized after the addition of 12 ml of a 0.150 M HNO3 solution if the unknown base concentration 0.0300 M give the possible identities for the unknown base
Saturday, September 27, 2014 at 9:47pm

Chemistry
If you dilute 14.0mL of the stock solution to a final volume of 0.350L , what will be the concentration of the diluted solution? Before it, there was a question: How many milliliters of a stock solution of 5.60 M HNO3 would you have to use to prepare 0.190L of 0.450 M HNO3? ...
Saturday, September 27, 2014 at 9:12pm

chemistry
an electron in n=5 emits 4052 nm to what energy level does the electron move
Saturday, September 27, 2014 at 8:11pm

chemistry
Imagine there is a tank of unknown gas that contains 53.31% carbon, 35.51% oxygen, and 11.18% hydrogen by mass. At 35.0 °C and 0.470 bar, 2.0 L of the gas has a mass of 3.3 g. Using this information, answer the following questions. a.) What is the empirical formula of the ...
Saturday, September 27, 2014 at 7:07pm

chemistry
A 8.50-g sample of solid AlCl3·6H2O was heated such that the water turned to steam and was driven off. Assuming ideal behavior, what volume would that steam occupy at 1.00 atm and 100.0 °C?
Saturday, September 27, 2014 at 7:04pm

chemistry
Air is 78.1% nitrogen, 20.9% oxygen, and 0.934% argon by moles. What is the density of air at 22 °C and 760 torr? Assume ideal behavior.
Saturday, September 27, 2014 at 6:51pm

chemistry
A 8.80-g sample of solid SnCl2·2H2O was heated such that the water turned to steam and was driven off. Assuming ideal behavior, what volume would that steam occupy at 1.00 atm and 100.0 °C?
Saturday, September 27, 2014 at 6:46pm

chemistry
Suppose 1.2x10^3 kg of C is mixed with 2.4x10^5g oxygen gas and carbon dioxide forms. 1. write the reaction and balance 2.which reactant is the limiting reagent and which reactant is in excess 3. How many grams of carbon dioxide will be formed.
Saturday, September 27, 2014 at 5:40pm

chemistry
2NiS2(s)+5O2(g)=2NiO(s)+4SO2(g) 1. how many kilograms of NiO would be formed from the reaction of .0125 mol of NiS2? 2. How many grams of O2 are needed to cmpletely react with 3.74 g of NiS2.
Saturday, September 27, 2014 at 5:38pm

Chemistry
500 g of Fe reacted with water to yield 4.2 g of H2. Fe3O4 was also produced in the reaction. What is the %yield of H2?
Saturday, September 27, 2014 at 4:47pm

chemistry
a student mixes 4 reagents together thinking that the solution will neutralize each other . The solution is mixed together are 50 ml of 0.100 M of HCL and 100 ml of 0,200 M of nitric acid 500 ml of 0.0100 M ca hydroxide and 200 ml of 0.100 M rubidium hydroxide . Did the acid ...
Saturday, September 27, 2014 at 3:41pm

chemistry
The half-life of oxygen-15 is 124 s. If a sample of oxygen-15 has an activity of 4800 Bq, how many minutes will elapse before it has an activity of 600 Bq?
Saturday, September 27, 2014 at 3:37pm

Chemistry
Please help! Calculate the standard change in enthalpy, ΔH°rxn, for the decomposition of calcium carbonate to calcium oxide CaCO3 (s) → CaO (s) + CO2 (g) Given that: ΔH°f CaCO3 (s) = -1206.9 kJ/mol ΔH°f CaO (s) = -635.1 kJ/mol ΔH°f CO2...
Saturday, September 27, 2014 at 3:20pm

Chemistry
Please help me! I don't know how to do this at all. Calculate the enthalpy for the reaction: NO (g) + O (g) → NO2 Given the following known reactions: NO(g)+O3 (g)→NO2 (g)+O2 (g) 03 (g)→1.5O2 (g) O2 (g)→2O(g) ΔH°=-198.9kJ ΔH°=-142....
Saturday, September 27, 2014 at 2:25pm

CHEMISTRY
Does a molecular compound in water have hydration or have ionization ?
Saturday, September 27, 2014 at 12:02pm

chemistry
in HNO3 titration, you add few drops of phenolphthalein indicator to 50.0 mL of acid in a flask. you quickly add 20.00 mL of 0.0547 M NaOH but overshoot the end point, and the solutions turn deep pink. instead of starting over, you add 30.00 mL of acid, and the solution turns ...
Saturday, September 27, 2014 at 6:53am

chemistry
If 70.0 mL of water is added to 30.0 mL of 0.400 M solution of NaOH, what is the new concentration of NaOH?
Saturday, September 27, 2014 at 4:25am

chemistry
A 4.78-g sample of aluminum completely reacts with oxygen to form 6.67 g of aluminum oxide Use this data to calculate the mass percent composition of aluminum in aluminum oxide. (Sorry need help with this!)
Saturday, September 27, 2014 at 3:07am

chemistry
Calculate the empirical formula for compound ethyl butyrate (pineapple oil): C, 62.04%; H, 10.41%; O, 27.55% Can someone show me the steps?
Saturday, September 27, 2014 at 2:17am

chemistry
230Th+He____223Po+2 2H+----- please complete this equation
Saturday, September 27, 2014 at 1:07am

chemistry
How do you calculate the mass percent composition of nitrogen in NO2?
Saturday, September 27, 2014 at 1:01am

chemistry
Determine the number of moles of H in 4.70mol H2O. Please help I tried different ways to do it and I got them all wrong.
Saturday, September 27, 2014 at 12:03am

Chemistry
In order to identify a compound using TLC it is necessary to spot a sample of the pure compound. Why is this necessary?
Friday, September 26, 2014 at 11:38pm

Organic chemistry
In order to identify a compound using TLC it is necessary to spot a sample of the pure compound. Why is this necessary?
Friday, September 26, 2014 at 11:36pm

Chemistry
What is the total ionic equation of this: 3CaCl2(aq) + 2K3PO4(aq) → Ca3(PO4)2(s) + 6KCl(aq) Shw all physical states of the reactants and products
Friday, September 26, 2014 at 11:17pm

Chemistry
Bones are mostly calcium phosphate. Calcium chloride reacts with potassium phosphate to form calcium phosphate and potassium chloride. Indicate the physical states or reactants and products a) Write the balanced equation of the information above b) Determine the total ionic ...
Friday, September 26, 2014 at 10:18pm

chemistry
An electrical heater delivers 4.070 kJ of energy (as heat) to a system consisting of the gas inside a cylinder having a movable piston. As a result, the piston moves against a constant external pressure such that P ∆V = 2.442 kJ. What is the change in internal energy for...
Friday, September 26, 2014 at 7:39pm

chemistry
Use the following values for the arrows in the drawing: a = 185 J of heat; b = 45 J of heat; c = 115 J of work; d = 40 J of work; e = 65 J of work; and f = 190 J of heat. Find the change in the internal energy of object A only. Use the First Law of Thermodynamics Be careful ...
Friday, September 26, 2014 at 5:02pm

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