Tuesday
May 3, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
Calculate the value of the thermodynamic equilibrium constant for the following reactions at 25.0 °C. (a) N2H4(g) + 2O2(g) 2NO(g) + 2H2O(g) Kp = H20=-228.6 NO= 86.69 N2H4= 159.3 02 = 0
Saturday, March 5, 2016 by Lia

chemistry
At 1500 °C, Kc = 5.67 for the reaction CH4(g) + H2O(g) CO(g) + 3H2(g) Calculated value of ΔG°1773 for the reaction at this temperature.
Saturday, March 5, 2016 by Ann

chemistry
Dr Bob, Thanks for your help. Ihad googled for 3 hours before asking you. For future reference, if anyone asks this question again, 10th grade chemistry, I found a video on You Tube that makes it easy to understand. It is, The Sci Guys, Ph indicator, acid-base indicator. ...
Saturday, March 5, 2016 by lulu

ANALYTICAL CHEMISTRY
A sample weighing 1.25 mg containing a certain compound M (FW 292.16 g/mol) was dissolved in solvent in a 5.00 mL volumetric flask. A 1.00 mL aliquot was drawn up, placed in a 10.00 mL volumetric and diluted to the mark with solvent. The absorbance of this solution at 340 nm ...
Saturday, March 5, 2016 by KAMBOYI K

chemistry
Calcium carbonate, CaCO3, when heated decomposes to calcium oxide and carbon dioxide. Calculate the mass of calcium oxide formed when 2.0 grams of CaCO3 is decomposed.
Saturday, March 5, 2016 by Unknown

chemistry
In the red cabbage lab, we just took the cabbage juice and in 5 separate cups mixed it with 5 different liquids, ex: coke, milk, cleaning agent, etc, and matched the color to a ph chart to tell if it was a base or an acid. Simple lab. The question needs a relatively simple ...
Saturday, March 5, 2016 by lulu

Chemistry
When perturbing the equilibrium with heating and cooling, how many times do you think the equilibrium can be shifted before it stops working? Why? How about modification of the equilibrium through changes in concentration?
Saturday, March 5, 2016 by Anonymous

Chemistry
I've been stuck on this question for awhile now. I'm having a lot of trouble figuring out how to start it. If you had added exactly 20.00 mL do d.i. water before the titration, calculate the molar concentration of OAc- would have been at the end of the titration. (...
Friday, March 4, 2016 by Rich

chemistry
how to find the mole ratio of salt to water of Mo(NO3)2.5H2O CaSO4.2H2O (CaSO4)2.H2O
Friday, March 4, 2016 by linda

chemistry
1. Given that 50 grams of ice is heated at -20.0 °C to steam at 135.0 °C. i. Show the graph of the changes from ice to steam ii. Calculate the energy needed to change the ice to steam Please use these values: Heat of fusion = 334.16 J g¯1 Heat of vaporization = ...
Friday, March 4, 2016 by bliss

chemistry
Consider the unbalanced reaction Ti(s) + Cl2(g) --> TiCl4(s) When 10.3 g of Ti react with 12.7 g of Cl2, 16.2 g of TiCl4 are obtained. The theoretical yield of TiCl4 is , the limiting reactant is and the percent yield is %. (Remember to use correct sig figs)
Friday, March 4, 2016 by Amanda

Chemistry
Explain the chemical changes that occur in the red cabbage lab that changes the color of the cabbage juice. I know it has something to do with the hydrogen ions and maybe something to do with the electrons, but I don't understand what or how to answer this question
Friday, March 4, 2016 by lulu

Chemistry
A solution is prepared by adding 45.0g of Na2SO4*6H2O to pure water to make 150mL of solution. What are molar concentrations of these ions in the resulting solution? Sodium Ion? Sulfate Ion? Phosphate Ion? I've determined the solution is 1.2M 45/250.16g/mol Na2SO4*6H2O = ....
Friday, March 4, 2016 by Kevin

Chemistry
Using your knowledge of chemical migration, outline the two most possible chemical migration pathways for non-polar C9H12 that has been spilled onto an open field on a warm spring day.
Friday, March 4, 2016 by Nick

Chemistry 101
In addition to uranium, which elements were known to emit radioactive "rays" before M. Curie discovered radium?
Friday, March 4, 2016 by Lilly

Chemistry 101
If the curries were able to extract 8.5ug of radium from 8.5 tons of pitchblende, what was their rate of recovery? (in percent please)
Friday, March 4, 2016 by Lilly

Chemistry 101
How many evaporation's did the curies have to make before they finally isolated radium?
Friday, March 4, 2016 by Lilly

Chemistry 101
This is the question 10.0 grams of nitrogen is reacted with 10.0 grams of the element phosphorus under certain conditions to yield trinitrogen diphosphide. Answer these questions. 1). Write a balanced equation. 2). which reactant is limiting? In excess? 3). Theoretically, how ...
Friday, March 4, 2016 by Lilly

Chemistry 101
If a solution containing 20.0 grams of nickle (11) chloride is mixed with an aqueous solution of containing 15.0 grams of silver nitrate,, determine the mount of silver chloride that theoretically will precipitate. How much nickle (11) nitrate is formed? Which reactant is ...
Friday, March 4, 2016 by Lilly

CHEMISTRY
Given: 3H2(g) + N2(g) 2NH3(g) If the reaction starts with 0.500 mol of H2, how many atoms of hydrogen in the compound NH3 would you expect to make?
Friday, March 4, 2016 by LUNGILE

chemistry
Given: 3H2(g) + N2(g) 2NH3(g) If the reaction starts with 0.500 mol of H2, how many atoms of hydrogen in the compound NH3 would you expect to make?
Friday, March 4, 2016 by LUNGILE

Chemistry 101
10.0 grams of nitrogen is reacted with 10.0 grams of the element phosphorus under certain conditions to yield trinitrogen diphosphide. Answer these questions. 1). Write a balanced equation. 2). which reactant is limiting? In excess? 3). Theoretically, how many grams of ...
Friday, March 4, 2016 by Lilly

Chemistry 101
If a solution containing 20.0 grams of nickle (11) chloride is mixed with an aqueous solution of containing 15.0 grams of silver nitrate,, determine the mount of silver chloride that theoretically will precipitate. How much nickle (11) nitrate is formed? Which reactant is ...
Friday, March 4, 2016 by Lilly

Chemistry
How many grams of solute are in 0.504 L of a 0.350 M K2CO3 solution?
Friday, March 4, 2016 by msid

Chemistry
Explain, in terms of collision theory, how and why a reaction’s rate changes as the reaction progresses.
Friday, March 4, 2016 by nan

chemistry
what chemical changes are responsible for the color changes in the red cabbage lab?
Friday, March 4, 2016 by lulu

Chemistry
Determine the rate law, including the values of the orders and rate law constant, for the following reaction using the experimental data provided. Q + X yields products Trial [Q] [X] Rate 1 0.12 M 0.10 M 1.5 × 10-3 M/min 2 0.24 M 0.10 M 3.0 × 10-3 M/min 3 0.12 M 0....
Friday, March 4, 2016 by nan

Chemistry
A match must be struck against an object to produce a spark to start the burning process. Once the match starts burning, it releases a large amount of energy. Describe, in detail, what the potential energy diagram would look like for the burning of a match, and explain how ...
Friday, March 4, 2016 by nan

Chemistry
How does the potential energy of the reactants compare to the potential energy of the products in an exothermic reaction, and where does the energy that is given off come from? Explain your answer in complete sentences.
Friday, March 4, 2016 by nan

Chemistry
Which reaction did you perform in the hands-on activity? Describe the chemical combination that you investigated. Also describe any observations from the investigation, including the temperature change of the container.
Friday, March 4, 2016 by nan

Chemistry
Ascorbic acid is a compound containing of three element C,H, and O when a 0.214g sample is burned in oxyzen 0.320g of CO2 and 0.0874g H2O are formed. What is the Empirical formula of ascorbic acid?
Thursday, March 3, 2016 by Asifur

chemistry
2.) If the volume of a gas at -73 degrees celcius is doubled while pressure is held constant, what will be its final temperature in degrees celsius? 5.) A gas storage tank at a large industrial plant is designed to provide fuel under constant pressure. When the plant is shut ...
Thursday, March 3, 2016 by Zoey

chemistry
what mass of CdS is produced if 4.55g of cadmium reacts with 2.00g of sulfur?
Thursday, March 3, 2016 by tim

Chemistry
Write an overall balanced equation for these unbalanced half-reactions: In --> In3+ Cd2+ --> Cd I multiplied both sides by integers to get the electrons to be equal on both sides but I don't know what the final overall balanced equation looks like.
Thursday, March 3, 2016 by Blake

Chemistry
Mole calculations: How much does 2.5 x 10^24 molecules of p2o3 weigh ?
Thursday, March 3, 2016 by Aria

chemistry
How many kilojoules are required to melt 15g of ice at 0 degree celsius, and raise the temperature of the liquid that forms to 85 degree celsius?
Thursday, March 3, 2016 by Kate

chemistry
the reaction A+3B—>2C+D is first order with respect to reactant A and second order with respect to reactant B if the concentration of A is doubled and the concentration of B is halved the rate of the reaction would---------------by a factor of-----------
Thursday, March 3, 2016 by ruth

chemistry
the reaction A+3B->2C+D is first order with respect to reactant A and second order with respect to reactant B if the concentration of A is doubled the concentration of B is halfed and the rate of the reaction would -------by a factor of --------
Thursday, March 3, 2016 by ruth

chemistry
the reaction A+3B->2C+D is first order with respect to reactant A and second order with respect to reactant B if the concentration of A is doubled the concentration of B is halfed and the rate of the reaction would -------by a factor of --------
Thursday, March 3, 2016 by ruth

Chemistry
A 3.50L balloon contains 0.178 mol of gas. If 0.094 mol of gas is added to the balloon, what will be the new volume?
Wednesday, March 2, 2016 by Bill

Chemistry
What is the unit for molality? The unit for molality is moles per kg Or M/kg
Wednesday, March 2, 2016 by Angelina

Chemistry
4.5 moles of oxygen reacting with enough sodium will form how many moles of sodium oxide? How do you solve?
Wednesday, March 2, 2016 by Mac

Chemistry
If you have 14.2 mol of C4H10 and 85.6 mol of O2, which is the limiting reagent? I calculated mass using m=N*M, giving me the answer that C4H10 is the limiting reagent. That being said, the answer on the back says O2.
Wednesday, March 2, 2016 by AlphaPrimes

Chemistry
When the sugar glucose, C6H12O6 is burned in air, carbon dioxide and water vapor are produced. Write the balanced chemical equation for this process, and calculate the theoretical yield of carbon dioxide when 1.00 g of glucose is burned completely.
Wednesday, March 2, 2016 by Kaili

Chemistry
24.0 mL of 2.4 M silver nitrate is mixed with 32.0 mL of 2.0 M sodium chloride. ( I wrote the balanced equation as AgNo3+NaCl -> NaNo3 + AgCl ) A) Identify the precipitate formed by name and formula. - I wrote AgCl (silver chloride) B) Calculate the mass of precipitate ...
Wednesday, March 2, 2016 by Sara

Chemistry
3. suppose a gas at STP. Calculate its pressure at 25 degrees celcius if volume remains unchanged 5. suppose 1.11 L of an unknown gas in a rigid container constant volume is cooled from 22 deg. C to -55 deg C. Calculate the new pressure of the gas 6.) Suppose a 50.0 cm ^3 ...
Wednesday, March 2, 2016 by Dina

Chemistry
If a 20mL sample of milk has a 0.027M concentration of lactic acid, what would the pH be? what would the concentration and pH be in one litre?
Wednesday, March 2, 2016 by Hally

Chemistry
Hydrogen sulfide gas burns in the presence of oxygen to produce sulfur dioxide gas and water vapor. Write a balanced chemical equation, including the physical state
Wednesday, March 2, 2016 by Jasmine

11th grade chemistry
The bottled butane gas is installed in an oven that can supply 0.125 g/hr .In a kitchen room of volume 32 m^3 (volume of air), the oven is made to operate for 2 hours. Assuming the kitchen room is closed, what is the mole composition of the atmosphere in the kitchen when ...
Wednesday, March 2, 2016 by angy

Chemistry
What set of hybrid orbitals is used by Xe in XeO3F2? dsp2 d2sp3 sp3 dsp3 d2sp
Wednesday, March 2, 2016 by Dave

Chemistry
How many millimoles of HCl (aq) are neutralized by 0.35 g of CaCO3 (sol)? mmol
Wednesday, March 2, 2016 by Karen

Chemistry
If a 20mL sample of milk has a 0.027M concentration of lactic acid, what would the pH be? what would the concentration and pH be in one litre?
Wednesday, March 2, 2016 by Hally

Chemistry
N = Sp.gr*1000* percent% / eq.wt Prepare 200 ml of 5 N H2SO4 solution from concentrated H2SO4 , if we know that Sp.gr = 1.84 g/ml , percent = 98% , At.wt for (H= 1 , S=32 , O =16 ) Thank you a lot
Wednesday, March 2, 2016 by MAD

chemistry
Please I need a detailed explanation, am stuck doing this assignment, at what temperature in kelvin will co2 molecules have an rms speed equal to hydrogen at 20 Celsius?
Wednesday, March 2, 2016 by Emmanuel

Chemistry
Write the oxidation half reaction for Magnesium metal and write the reduction half equation for Cu^2+ ions? I don't understand, please give me a simple explanation.
Tuesday, March 1, 2016 by Stacy

Chemistry
Some hydrogen is collected over water at 10 degrees C and 105.5 kPa pressure. The total volume of the sample was 1.93 L. Calculate the volume of the hydrogen or reacted to STP.
Tuesday, March 1, 2016 by Charlie

Chemistry
Calculate the amount of heat energy transferred in the following situations: the temperature of 1.0g water rises from 22.5 degrees C to 24.5 degrees C. Feel like I am missing givens. Help! There are a few more like this but I just need to know how to set it up.
Tuesday, March 1, 2016 by Ryan

Chemistry lab
Discuss three unavoidable sources of error in Part 1 (the synthesis of the crystals) of this experiment and identify the major factors that would explain a less- than-100% yield. Note: human error is not an acceptable answer. Was the alum not dry enough for impurities to give ...
Tuesday, March 1, 2016 by Jake

Chemistry
How many mL of 0.101 M HCL are needed to neutralize 1.00 g of potassium hydroxide?
Tuesday, March 1, 2016 by Jennifer

chemistry
Calculate the percent ionization of a .31 molar solution of acetic acid. The ionization constant of acetic acid is 1.8 x 10^-5
Tuesday, March 1, 2016 by Avery

Organic Chemistry
We used sodium dichromate in sulfuric acid to oxidize borneol to camphor. Suppose you needed to prepare benzaldehyde from benzyl alcohol. Would the sodium dichromate be the best choice for this oxidation or are there better choices? Explain.
Tuesday, March 1, 2016 by Alyssa

chemistry
The three substances that can reduce Ag+ to Ag, but will not reduce Sn2+ to Sn are Zn Pb H2 Mg Cu I2 Al Ca
Tuesday, March 1, 2016 by Taylor

Chemistry
Show the calculation for the limiting reagent when 0.853g of sodium sulfate (95% pure) react with 1.707g of barium hydroxide octahydrate (87% pure) to produce a precipitate of barium sulfate. I've determined the equation is Na2SO4+Ba(OH)2*8H2O=BaSO4+2NaOH However, that is ...
Tuesday, March 1, 2016 by Kevin

Chemistry
If 258 mL of 2 molar HCl solution is added to 342 mL of 4.3 molar Ba(OH)2 solution, what will be the molarity of BaCl2 in the resulting solution? Answer in units of M.
Tuesday, March 1, 2016 by Avery

Chemistry
A 69 mL sample of a solution of sulfuric acid is neutralized by 41 mL of a .161 M sodium hydroxide solution. Calculate the molarity of the sulfuric acid solution. Answer in units of mol/L.
Tuesday, March 1, 2016 by Avery

chemistry
3.05 g of hydrated copper sulphate produces 1.94g of anhydrous salt.assuming complete removal of all water of crystallization,determine the formula of hydrated copper sulfate
Tuesday, March 1, 2016 by maria

Chemistry
When an aqueous solution of sodium hydroxide, NaOH, is added to an aqueous solution of chromium(III) nitrate, Cr(NO3)3, a precipitate of chromium(III) hydroxide, Cr(OH)3, forms. Write a balanced net ionic equation for this reaction.
Tuesday, March 1, 2016 by Tina

Chemistry
How is 4FeS2 + 11O2 = 2Fe2O3 +8SO2 a single replacement reaction?
Tuesday, March 1, 2016 by Gary

Chemistry
A 0.10M solution of a certain monoprotic weak acid has a pH of 2.44. Calculate Ka.
Tuesday, March 1, 2016 by Jackson

Chemistry (stoichiometry)
22 moles of benzene are completely reacted with molecular oxygen, how many moles of carbon dioxide will be produced? and if 150 grams of water were produced, how many moles of oxygen must have reacted
Tuesday, March 1, 2016 by Alex

Chemistry- Dr.Bob
What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is the physical state of water liquid? The explanation from bobpursly was this The sum of heats gained =0 80(cice)(0+15)+80Hf+80cw(...
Tuesday, March 1, 2016 by Student

Chemistry-Dr.Bob 222
What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is the physical state of water liquid? I still don't understand how to do this.
Tuesday, March 1, 2016 by Student

Chemistry
Please sir solve this... 6.3 gm of oxalic acid (eq. Wt.=63) is dissolved in 500 ml solution what will be the normality of the solution?
Tuesday, March 1, 2016 by Pradeep

Chemistry
I was given a list of 14 different solutions, and My homework question asks which of the solutions exhibit the common-ion effect and which ones are buffers? But, how would I be able to tell???
Monday, February 29, 2016 by CeCe

Chemistry (Food)
Which of the following are B vitamins? Check ALL that apply. A). ascorbic acid B). retinol C). calciferol D). thiamine E). niacin
Monday, February 29, 2016 by Dominick

Chemistry
In the voltaic cell that is represented as: Cu | Cu2+ || Fe | Fe2+. The only anion in solution in the cells and salt bridge is the nitrate ion. The directions the electron external circuit and NO3- flow in the salt bridge circuit will be: *electron flow is Fe to Cu *electron ...
Monday, February 29, 2016 by Mikah

Chemistry
The three substances that can reduce Ag+ to Ag, but will not reduce Sn2+ to Sn are Zn, Pb, H2, Mg, Cu, I2, Al, Ca
Monday, February 29, 2016 by Taylor

Chemistry (Food)
The average energy yield per gram of carbohydrate and of fat is A).4 kcal and 9 kcal, respectively B).9 kcal and 4 kcal, respectively C).9 kcal each D).4 kcal each
Monday, February 29, 2016 by Dominick

Chemistry
what type of reaction occurs in Al+SnCl4 ? and what is the balanced equation
Monday, February 29, 2016 by Camila

Chemistry
What is delta h for reaction between h2o2 and ethene to give ethylene glycol if HO-OH is 49 kcal/mol and C=C 65 kcal/mol Please show ur work
Monday, February 29, 2016 by Brahamanand

Chemistry
I need major help with balancing redox reactions. I can't seem to get this one: (in basic conditions) NBr_3(aq)=> N_2(g) + Br^-(aq) + HOBr(aq) I don't know how to split this up properly, and when I do it is like impossible to balance it. Thanks!
Monday, February 29, 2016 by Betty

Chemistry
What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is the physical state of water liquid? I don't understand the set up. The setup is like this (answered by bobpursly): The sum of...
Monday, February 29, 2016 by Student

Chemistry
CH4 (g)+ H2O (g) --->/<---- 3H2 + CO Use Le Chateliers Principle to explain what will happen to the number of moles of hydrogen at equilibrium when a) CO is removed b) Water Vapor is removed c) Methane is added d) CO is added e) Pressure is increased by adding argon gas...
Monday, February 29, 2016 by Student

Chemistry... again
How does a polar bond differ from a nonpolar bond? Explain your answer. All I need are ideas, not the word-for-word answer.
Monday, February 29, 2016 by Leet Speaker

Chemistry
Highest ionization energy to lowest I be ci f
Monday, February 29, 2016 by Anonymous

Chemistry
If you make a solution in the laboratory that contains 0.1 M acetic acid (CH3COOH), what concentration of hydronium will you have once the solution equilibrates?
Monday, February 29, 2016 by Rose

Chemistry
If you make a solution in the laboratory that contains 0.1 M hydrochloric acid, what concentration of hydronium will you have?
Monday, February 29, 2016 by Rose

chemistry
1. what mass of sodium hydroxide is required to make up 100 mL of 0.5000M solution 2.What volume of this solution must be diluted down to 100 mL if 0.100M solution of NaOH is required?
Monday, February 29, 2016 by Anonymous

Some Chemistry Questions
I got three questions. If you were making a tool used to handle live electrical wires, which class of materials would you most likely use? ***Semimetals Metalloids Nonmetals Metals Which of the following changes gives no evidence that a chemical reaction has taken place? A ...
Monday, February 29, 2016 by Leet Speaker

Chemistry
what is the concentration of each substance if a solution is prepared by mixing 5.00g of NaC2H3O2 with 15.0 ml of 1.45M acetic acid and then bringing the total volume to 250.0 ml?
Monday, February 29, 2016 by Ali

Chemistry
CH4 (g)+ H2O (g) --->/<---- 3H2 + CO Use Le Chateliers Principle to explain what will happen to the number of moles of hydrogen at equilibrium when a) CO is removed b) Water Vapor is removed c) Methane is added d) CO is added e) Pressure is increased by adding argon gas...
Monday, February 29, 2016 by Student

Chemistry
What is the final temperature and physical state of water when 250 grams of water at 85 degrees C is added to 80.0 grams of ice at -15 degree C? Is the physical state of water liquid? I don't understand the set up that I have to set the equation equal to 0 ...
Monday, February 29, 2016 by Student

Chemistry
The pH of a 0.095 M solution of an unknown monoprotic acid is 5.42. Calculate the Ka of the acid. A) 3.8 x 10-6 B) 3.6 x 10-7 C) 1.5 x 10-10 D) 2.6 x 10-9 E) 2.8 x 10-8 ​
Monday, February 29, 2016 by Bronwyn

Chemistry
I got 1.11 x 10^-6 for K. Here is my work: x= 0.004 -2x= -0.008 (change for CH4) Equilibrium for CH4 is 0.087 - 0.008= 0.079 Change in eq for C2H2 is 0.004 and eq is 0.004 (=x) Change in eq for H2 is 0.012 Eq for H2 is 0.012 K= [C2H2][H2]^3/[CH4]^2 K= (0.004)(0.012)^3/(0.079)^...
Monday, February 29, 2016 by Student

Chemistry
What is the value of the equilibrium constant for the overall reaction? ​​ AgCl (s) + 2NH3 (aq) Ag(NH3)2+ (aq) + Cl- (aq) Knet = ?
Monday, February 29, 2016 by Bronwyn

Chemistry
How many milliliters of 2.00 M NaHO solution are needed to neutralize a 8.00 mL of 3.50 M H2SO4 solution?
Monday, February 29, 2016 by Hailey

Chemistry
I need to write a hypothesis on limiting reactants.
Monday, February 29, 2016 by Keron

cHEMISTRY
What mass of AgCl(143.32g/mol) is formed from the reaction of a 0.109 M MgCl2 solution with excess AgC2H3O2?
Monday, February 29, 2016 by lIZ

Organic Chemistry
Hello, I have done an experiment in Organic Chemistry called :SN1 Reaction: Synthesis of t-amyl chloride from t-amyl alcohol, there are some questions that I am unsure about, 1) What are the 2 rules of HCl in this reaction? Can you use NaCl instead of HCl to synthesize t-amyl ...
Monday, February 29, 2016 by Mohammed

Chemistry
calculate the bond energy for diatomic oxygen O2 given that standard enthalpy of atomization of oxygen (ΔH) = 249.17KJ
Monday, February 29, 2016 by Solomon

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