Tuesday
June 28, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
If 5.00g of glucose were to react completely with an excess of oxygen, how many grams of carbon dioxide would be produced?
Tuesday, June 28, 2016 by helena15zgeo

Chemistry
100g of water is added into 10.6M NaOH solution. The diluted NaOH then neutralized completely with H2SO4 . density of NaOH is 1.08g/ml . calculate the mole fraction of NaOH in diluted solution .
Tuesday, June 28, 2016 by Amy

Chemistry
The volume of 18 molar concentrated H2SO4 that must be diluted with distilled water to prepare 10 liters
Monday, June 27, 2016 by Angel Kenkpen

chemistry
sorry,for the mistake. To 200mL of a 0.1M solution of a CH3COOH (Ka=1.8 x 10-5) 70mL of a 0.2M solution of NaOH have been added.calculate the pH before and after the NaOH addition.
Monday, June 27, 2016 by Anonymous

chemistry
I am trying to calculate the how amount of Tris-bicarbonate should be added in the reaction. I would like to have final volume of bicarbonate 10mM in 2ml reaction. I made Tris-base (1M, 100ml) and instead of HCl, CO2 was bubbling to set pH7.5. 0.1L*0.1M= 0.01 moles of Tris &#...
Monday, June 27, 2016 by chocho

chemistry
How could you prepare: a ) 2-chloropropane from 2-propanol? b) 2-butanone from 2-butanol? c) ethyl acetate CH3COOC2H5 from ethanol? d) 2-methyl-2-butene from 3-methyl-2-butanol?
Monday, June 27, 2016 by vicky

Organic Chemistry
Suppose 5.00 gram of a mixture of aspirin, caffeine, and acetanilide was dissolved in enough solvent (methylene chloride) to make a total of 100.00 mL volume. You took 10.00 mL from it and isolated its components using the same protocol you did in the lab. You obtained: ...
Monday, June 27, 2016 by David

Chemistry
I had to do a lab and had to calculate the molar mass for a substance with this equation MM=Mrt/pv but we had to calculate the mass of the substance and its temperature experimently. My question is why did we have to boil the liquide in a water containing becker. Why did we ...
Monday, June 27, 2016 by Gabby

chemistry
write the electron-dot formula for the following compound HCN,Co2,H2O@,O2,H2O
Monday, June 27, 2016 by maawiya muhammad diggie

Chemistry
Hi I got a question if we have An unknow but we have its molecular formula of that unknown compound can that Molecular formula ALWAYS tell us exactly what compound we have?
Monday, June 27, 2016 by Bonny

Chemistry
What is the amount of oxygen needed to create output 20gm?
Monday, June 27, 2016 by LABIBUL HASAN

Chemistry
Sorry, I have been stuck on this question. I would appreciate if someone could help me out. Approx how many mL of 0.25M BaCl2 solution would be required to precipitate all the sulfate if we assume the sample is pure sodium sulfate? Assume that the density of the barium ...
Sunday, June 26, 2016 by Mike

chemistry
How many degenerate orbitals have the following name? 2s 3p 5d 4p 5s I dont get this question
Sunday, June 26, 2016 by lo

Chemistry
The sulfate in a 0.2345 g sample of a mixture containing only K2SO4 (fm = 174.26) and Na2SO4 (fm = 142.04) is to beanalyzed by precipitating all the sulfate as barium sulfate, BaSO4 (fm = 233.39) by the addition of excess BaCl2. Na2SO4 + BaCl2 image from custom entry ...
Sunday, June 26, 2016 by Esraa

chemistry
Which of the following sets of quantum numbers are not allowed. For each incorrect set, state why it is incorrect. For each correct set, name the atomic orbital. i. n=4, l=3, ml =2, ms =-1/2 ii. n=2, l=1, ml =-1, ms =-1 iii. n=5, l=-4, ml =2, ms =+1/2 can you guys help me my ...
Sunday, June 26, 2016 by lo

chemistry
This statement is writing in my textbook can someone please explain to me what it mean: Determining the position of electrons, eliminates their wave properties.
Sunday, June 26, 2016 by lo

Chemistry
How much energy is released when 2.50g of NH3 rxs with excess N20 given the following 2NH3+3N2O -> 4N2_3H2O; DELTA(H)=-1010KJ. Please give work and setup :)
Sunday, June 26, 2016 by Alex

Chemistry
a 2.00 g sample of C6H402 is burned in a calorimeter whose heat capacity is 8kj/C. The delta T is +7.13 degrees C. What is the enthalpy change per mole?
Sunday, June 26, 2016 by Alex

Chemistry
64g of oxygen reacts completely with methane gas to form 44g of carbon dioxide gas and 36 g of water vapour. Calculate the amount of methane that takes part in the reaction .
Saturday, June 25, 2016 by Anonymous

CHEMISTRY
THIS IS THE 3RD TIME POSTING THIS, PLEASE HELP ME ANSWER THIS THE HOMEWORK IS DUE TONIGHT. Write formulas for the compounds that form from In (Assume In charge is 3+.) and each of the following polyatomic ion: NO−3, SO2−4, PO3−4 -3, -4, -4 ARE THE CHARGES. ...
Friday, June 24, 2016 by MELISSA

CHEMISTRY
THIS IS THE 3RD TIME POSTING THIS. PLEASE HELP ME ANSWER THIS. THE HOMEWORK IS DUE TONIGHT. Write formulas for the compounds that form from Sr and each of the following polyatomic ion: NO−3, SO2−4, PO3−4. THE -3, -4, -4 ARE THE CHARGES, CANT TYPE SUBSCRIPT ON...
Friday, June 24, 2016 by MELISSA

CHEMISTRY
Write formulas for the compounds that form from Sr and each of the following polyatomic ion: NO−3, SO2−4, PO3−4. APPARENTLY SrNO6, SrSO4 , Sr3PO8 is wrong
Friday, June 24, 2016 by MELISSA

CHEMISTRY
Write formulas for the compounds that form from In and each of the following polyatomic ion: NO−3, SO2−4, PO3−4. (Assume In charge is 3+.) InNo9, InSO6, AND InP4 is wrong
Friday, June 24, 2016 by MELISSA

CHEMISTRY
Provide the name of the oxyanion of the acid HNO2(aq) I ENTERED Carbonate ion BUT ITS WRONG
Friday, June 24, 2016 by MELISSA

Chemistry
Use the periodic table to answer this question. A student dissolves 24.2 g of NaCl in 500 mL of water. Another student dissolved 24.2 g of KI in 500 mL of water. Why do the two solutions have different molarities? The volumes of the solutes differ. The final volumes of ...
Friday, June 24, 2016 by Noah Love

Chemistry
The solubility of sodium chloride is 35.9 g/100 g H2O at 20°C. 35.9 g of sodium chloride are added to 100 g of water, and all of it dissolves. Another solution is made from the same amount of salt and the same amount of water. This time some solid remains undissolved. What...
Friday, June 24, 2016 by Amanda Perry

CHEMISTRY
Write formulas for the compounds that form from In and each of the following polyatomic ion: NO−3, SO2−4, PO3−4. (Assume In charge is 3+.) In(+3 charge) NO3(-1 CHARGE) SO4(-2 charge) P4(-3 charge) Re posting this a little differently. hopefully someone can ...
Friday, June 24, 2016 by MELISSA

CHEMISTRY
Write formulas for the compounds that form from Sr and each of the following polyatomic ion: NO3 −1, SO4 −2, PO4 −3. SR (+3 CHARGE) NO3(-1 CHARGE) SO4(-2 CHARGE) PO4(-3 CHARGE) Re posting this question. hopefully someone can help me answer this now. Please ...
Friday, June 24, 2016 by MELISSA

Chemistry
What is the theoretical yield of Fe2(SO4)3 if 20.00 g of FePO4 reacts with an excess of Na2SO4?
Friday, June 24, 2016 by Jacke

CHEMISTRY
Write formulas for the compounds that form from In and each of the following polyatomic ion: NO−3, SO2−4, PO3−4. (Assume In charge is 3+.) InNo9, InSO6, AND InP4 is wrong
Friday, June 24, 2016 by MELISSA

CHEMISTRY
Write formulas for the compounds that form from Sr and each of the following polyatomic ion: NO−3, SO2−4, PO3−4. APPARENTLY SrNO6, SrSO4 , Sr3PO8 is wrong
Friday, June 24, 2016 by MELISSA

Science-chemistry
an alloy of metal A and B in the eatio of 2:5 and weighs 36g the percentage of metal A is 22.22% if atomic mass of A is 40 then atomic mass of metal B is
Friday, June 24, 2016 by Sukrit

chemistry
What volume of 6M NaOH needed to prepare 250ml 0.1M NaOH?
Thursday, June 23, 2016 by alfa

Chemistry PLS HELP
The cover plate is removed from the gas jars shown iin the diagram. Nitrogen dioxide is a brown gas. After several days, the color of the gas is the same in both of the jars. What explains this change? So the picture shows this jar and nitrogen and nitrogen dioxide is ...
Thursday, June 23, 2016 by Cheezel

chemistry
Find the molar solubility of BaCrO4 (Ksp= 2.1 × 10−10) in 3.5 × 10−3 M Na2CrO4
Thursday, June 23, 2016 by becca

Chemistry
X forms an oxide X2O3 , 0.36 grams of X forms 0.56 grams of X2O3 .so that atomic weight of X is
Thursday, June 23, 2016 by Soujanya

Chemistry
In 1985 benitoite became the California “state gemstone.” Found only in a tiny mine near Coalinga, California, it is a silicate of barium and titanium with trace impurities that cause a range of hues from colorless to blue to pink. Its general formula is BaTi(SiO3)3...
Thursday, June 23, 2016 by Anonymous

Chemistry
A 1.00 L flask is filled with Ar by water displacement at 20.0°C. the atmospheric pressure is 759.6 torr. after correcting for water vapor pressure in the flask, determine how many moles of Ar are present
Wednesday, June 22, 2016 by lol no

Chemistry
In 1985 benitoite became the California “state gemstone.” Found only in a tiny mine near Coalinga, California, it is a silicate of barium and titanium with trace impurities that cause a range of hues from colorless to blue to pink. Its general formula is BaTi(SiO3)3...
Wednesday, June 22, 2016 by Susie

Chemistry
3 Cl2 + 6 KOH go to KClO3 + 5 KCl + 3 H2O how many moles of KClO3 form when 2 grams of KOH react completely
Wednesday, June 22, 2016 by Samantha

Chemistry
The amount of energy released by the combustiom of 100 g of C2H2 (g) is ______ MJ. 2CH2 + 5O2 ----> 4CO2(g) + 2H2O(g) ΔH= -2511.0 kJ Do I use ΔH = Hproducts - Hreactants? And if so how would that help me solve for the energy released?
Wednesday, June 22, 2016 by Anonymous

Chemistry
For the reaction: Pb(NO3)2(aq) + 2KCl(aq)->PbCl2(s) + 2KNO3(aq) How many grams of PbCl2 will be formed from 63.0 mL of a 1.60 M KCl solution?
Wednesday, June 22, 2016 by Terri

chemistry
Write the condensed structural formulas for the following alcohols."" Correct the incorrect names."" 4-methyl-1-pentanol 2-methyl-2-butanol 3-ethyl-1-butanol 2, 2-diethyl-4-pentanol 3-ethyl -2-hexanol IS THERE ANY WRONG NAMES??
Wednesday, June 22, 2016 by angy

Chemistry
How many grams of NH3 is there in 800 cm^3 at STP of NH3 gas?
Wednesday, June 22, 2016 by Shipra

chemistry
The amount of energy required to remove an electron from the surface of Hg is 7.22x10^-19 J. What is the threshold frequency of mercury? I got 1.09*10^15 hz is it right?
Tuesday, June 21, 2016 by lo

Chemistry
Given that W = -PatmΔV, if a gas expands into a vacuum, the sign of W is ? 1. Positive: work is being done on the gas 2. Negative: work is being done on the gas 3. Positive: work is being done by the gas 4. Negative: work is being done by the gas 5. ZERO: no work is being...
Tuesday, June 21, 2016 by Melodie

Chemistry
The experimentally determined rate law for the reaction H2 + NO --> ½N2 + H2O is Rate = k[H2][NO]2. Is the mechanism below possible? Step 1: H2 + NO --> N + H2O Slow Step 2: N + NO -->N2 + O Fast Step 3: O + H2 --> H2O Fast 1. Yes...
Tuesday, June 21, 2016 by Hs

Chemistry
Is NH4+ polar or non polar?
Tuesday, June 21, 2016 by sarah

chemistry
Is NH4+ po;ar or non polar?
Tuesday, June 21, 2016 by sarah

Chemistry
Calculate the mass of HF required to prepare 200 mL of 0.25 mol/L solution. P = 40%; d = 1.14 g/cm3
Tuesday, June 21, 2016 by Jacke

Chemistry
I have the answer to this question but the book does not explain WHY this is a good buffer solution? It uses pH=pKa - log(base/acid) and shows 7.2=7.2 - log(1). I don't understand why they can only use pKa7.2 and ignore the pKa 12.7. You are instructed to prepare 100ml of ...
Tuesday, June 21, 2016 by Kelsey

Chemistry
Consider a cylinder containing 2 mol of an ideal gas at an initial temperature of 25 C. The cylinder is fitted with a piston on which a weight is placed, subjecting the gas to a constant pressure of 2.66 atm. The cylidner is then wrapped with a heater, from which 1.50 kJ of ...
Tuesday, June 21, 2016 by Chris Tesler

Chemistry
A 53.8-mg sample of sodium perchlorate contains radioactive chlorine-36 (whose atomic mass is 36.0 amu). If 29.6% of the chlorine atoms in the sample are chlorine-36 and the remainder are naturally occurring nonradioactive chlorine atoms, how many disintegrations per second ...
Tuesday, June 21, 2016 by Harry

Chemistry
Rule of thumb gives the activation energy of most organic reactions as approximately 50 kJ/mol. Based on that, calculate by what factor the reaction rate increases when the temperature climbs from 25°C to 45°C. 1. 3.6 2. 3.2 x 1046 3. 1.001 4. 1.3
Tuesday, June 21, 2016 by TS

Chemistry
will red blood cells undergo hemolysis, crenation or no change at all. 10%m/v NaCl 2% m/v glucose H2O 5% m/v glucose how would I come up with the answer I read the chapter and i'm confused
Tuesday, June 21, 2016 by Jason

chemistry
Why reversible reaction never complete
Tuesday, June 21, 2016 by ali

chemistry
What is pOH of 0.1M H2SO4?
Monday, June 20, 2016 by padamraj

chemistry
Ba(OH)2(aq) + HCl(aq) BaCl2(aq) + H2O (g) Consider the unbalanced equation above. What is the concentration of the original hydrochloric acid solution if 18.0 mL of the acid reacts with 45.5 mL of 0.280 M barium hydroxide?
Monday, June 20, 2016 by zack

Chemistry
Describe the ammonium ion, NH4+, and the sulfate ion, SO42-. What compounds would these ions form with potassium and fluoride ions? Write the formula units for the resulting compounds.
Monday, June 20, 2016 by Adimi

Chemistry
How many liters of 0.85 M HCl solution would react completely with 3.5 moles Ca(OH)2?
Monday, June 20, 2016 by Kevin

Chemistry
The Ka of an acid is 1.3 x 10–7. Based on the Ka and its relationship with Kw, what is the value of Kb?
Monday, June 20, 2016 by Kelly

Science chemistry
Which compound has the melting point of -23 degree Celsius and boiling point of 77 degree Celsius ? Thx....
Monday, June 20, 2016 by Tan

chemistry
a hydrocarbon was burnt completely and the products were bubbled into excess of Ca(OH)2 solution. The resulting mixture was filtered, and the residue dried and weighed. The mass of the hydrocarbon was found to be 10.00g. In a separate experiment, the same amount of hydrocarbon...
Sunday, June 19, 2016 by kandace

Chemistry
A solution is made by dissolving 32g KCIO3 in 100g H20 at 80C. The solution is cooled to 10C. Describe what you would observe as it cooled and state what temperature this first occurs at. What mass of crystals would settle out of the solution?
Saturday, June 18, 2016 by Naomi

chemistry
4gm of NaOH can be neutralised by? 1) 100ml of 1N HCl 2) 200ml of N/2 H2SO4 3) 1000ml of N/10 KOH 4) 2000 ml of M/20 H3PO4
Saturday, June 18, 2016 by Mukul

Chemistry
Write the equation for the reaction of iron and oxygen. Label the oxidizing reagent, the reducing agent, the reduced element, and the oxidized element.
Friday, June 17, 2016 by Tammy

Chemistry
in the reactionN2+3h2=2nh3 42.02 g of n2 is consumed of all gases are at satp the number of moles of nh3 produced is
Friday, June 17, 2016 by koko

chemistry
calculate the momentum of a particle ,whose de Broglie's wave length is 0.1nm ?
Friday, June 17, 2016 by nitin

chemistry
what is the mole of a solution that has 6 mole of Ca-Cl 2 in 3 kg of water?
Thursday, June 16, 2016 by Anonymous

Chemistry
When the pressure exerted on 1.0L of an ideal gas is quadrupled, and the kelvin temperature is tripled,what does the volume become?
Thursday, June 16, 2016 by Kyla

Chemistry
How to determine SiO2/Na2O ratio after mixing Na2SiO3 (SiO2=30%, Na2O=9%, water=61%)and NaOH (8M)solutions?
Thursday, June 16, 2016 by MJ

chemistry
You have a solution that contains 0.25g grams of oxalic acid dissolved in 100 mL of water. This solution is placed in a separating funnel, and the 100 mL of butanol is added to the solution. calculate the mass of oxalic acid in the organic solvent
Thursday, June 16, 2016 by Grace

Organic chemistry
What are the examples of compounds extracted by solvent diethyl ether?
Thursday, June 16, 2016 by Ummi Hani

Chemistry
How many ml of 8.00 M Na OH is required to neutralize 200 ml of 4.00 M HCl?
Thursday, June 16, 2016 by Anonymous

chemistry
Write the oxidation and reduction half-reactions for a silver-chromium voltaic cell. Identify the anode, cathode, and the direction of electron flow. Ag+ + e-  Ag Cr  Cr2+ + 2e- or Cr  Cr3+ + 3e- ????? Which is the correct equation for the chromium side...
Thursday, June 16, 2016 by S

CHEMISTRY
Why is I- a stronger reducing agent than F-?
Thursday, June 16, 2016 by Jordan

Chemistry
Consider the following reaction: CO(g)+2H2(g)⇌CH3OH(g) This reaction is carried out at a specific temperature with initial concentrations of [CO] = 0.27 M and [H2] = 0.49 M. At equilibrium, the concentration of CH3OH is 0.11 M. Find the equilibrium constant at this ...
Thursday, June 16, 2016 by Donnie

Chemistry
what is the percent by mass of a solution by dissolving 200 g of NaCI in 500 mL of water?
Wednesday, June 15, 2016 by Annyssa

Chemistry
Considering only the molecular orbitals formed by combinations of the s atomic orbitals in the valence shell, how many molecular orbitals can be formed by 5000 sodium atoms?
Wednesday, June 15, 2016 by Jack

Chemistry 171 Lab
Suppose we collect hydrogen gas, H2(g), over water at 21◦C in a vessel with total pressure of 743 Torr. If the hydrogen gas is produced by the reaction of aluminum with hydrochloric acid: 2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g) what volume of hydrogen gas will be ...
Wednesday, June 15, 2016 by Rae

Chemistry
the question says: Calculate the mass of soap (NaC17H35COO) which contains 1.25 grams of Carbon. Do I use the percentage composition of soap and the mole?
Tuesday, June 14, 2016 by Lauren

chemistry
A reaction has a first order rate constant of 6.11x10-5 s-1 at 25C and 0.00221 s-1 at 85oC. What is the value of the rate constant at 63oC?
Tuesday, June 14, 2016 by Basil

Chemistry
Combustion of 1g of an organic compound known to contain C, H and O produces 2.36g CO2, 0.64g H2O. What is the empirical formula?
Tuesday, June 14, 2016 by Marie

Chemistry
How much heat is needed to raise the temperature of 5.58 kilograms of iron from 20.0°C to 1000.0°C? Specific heat of iron is 450,000 J/(kg x °C). Type the correct answer to 3 significant digits.
Tuesday, June 14, 2016 by Sylvie

chemistry
_____ H2C2O4 + _____ NaOH ______Na2C2O4 + _____ H2O
Tuesday, June 14, 2016 by jamie K

chemistry lab
Why do we have to weight the beaker with salt and water before dissolving the Nacl ? why is it incorrect to weight it after we dissolve it
Tuesday, June 14, 2016 by terenlo

Chemistry
A sample of beer is 4.6 % by mass C2H5OH. The density of beer is 0.93 g/ml. What is the molar concentration of C2H5OH in this sample of beer? a. 9.7 x 10-4 b. 1.13 x 10-4 c. 0.975 M d. 1.13 M I did 0.046x930 g/L =42.78 mass alcohol 42.78/molar mass of C2H5OH (46.068) = 0.928 ...
Tuesday, June 14, 2016 by TS

Chemistry
The gas phase reaction X+Y⇄ Z is first order in Y and second order in X. If the concentration of X is double and concentration of Y is tripled. The reaction rate would be increase by a factor of: then, Rate= k [x]^2[y] --> k[x]^4[y}^3 is this the correct line of ...
Tuesday, June 14, 2016 by ED

CHEMISTRY
If you used only photons that were dropping from the n = 6 shell to the n = 1, how many of these photons would be required to keep a 100 Watt light bulb lit for 10 minutes?
Monday, June 13, 2016 by Jessica

chemistry
how is copper 2 sulphate formed from copper oxide and sulpheric acid and why is it formed?
Monday, June 13, 2016 by anonymous

chemistry
why is lead 2 iodide produced from the reaction of lead 2 nitrate and potassium iodide?
Monday, June 13, 2016 by anonymous

Chemistry
If you were told that a ball had a wavelength of 5 x 10-26 nm at a velocity of 60 mph, what would be the mass of that ball in pounds?
Monday, June 13, 2016 by Jessica

Chemistry
Prepare M/20 oxalic acid solution.Using this solution, find molarity, strength, and percentage purity of the sodium hydroxide solution.
Monday, June 13, 2016 by Sara

chemistry
How would you prepare 3.5 L of a 0.9M solution of KCl? A. Add 23 g of KCl to a 3.5 L container; then add enough water to dissolve the KCl and fill the container to the 3.5 L mark. B. Add 233 g of KCl to a 3.5 L container; then add enough water to dissolve the KCl and fill the...
Monday, June 13, 2016 by donna

Chemistry
I have 25 million gallons of water at a pH of 6.5. I add 17.4 million gallons of 12.5% by wt sodium hypochlorite (NaClO) at a pH of 12.5 to this water. What will my pH of my final solution be? It's been about 5 years since I took chemistry and I just don't remember how...
Monday, June 13, 2016 by Kelsey

chemistry
4NH3 + 5O2 --> 4NO + 6H2O 170g of ammonia (NH3) are allowed to react with 384g of O2. how many moles of NO is produced? and also how many grams of NO will be produced?
Monday, June 13, 2016 by shriya

chemistry
C3H8 + 5O2 --> 3CO2 + 4H2O 22 moles of propane (C3H8) react with 200 moles of oxygen gas. how many moles of the non limiting reactant remain?
Monday, June 13, 2016 by shriya

analaytical chemistry
a student mixes equal volume of 1 molar tin chloride and coper sulfate and observe tha no preciptate forms .then the students mxis equal volume of 1molar solution of zinc sulfate and tin floride and observe the formation of precipitate .which compound is precipitate
Monday, June 13, 2016 by Gebru

chemistry
How can diamond be formed artificially
Monday, June 13, 2016 by udeh

Chemistry
A Chemist wanted to determine the percentage of calcium carbonate in a sea shell. He collected a number of sea shells which he crushed into a fine powder. To 2.65 grams of sea shell powder he added 25.0mL of 5.0M Hydrochloric acid. When all the fizzing ceased, he filtered the ...
Monday, June 13, 2016 by James

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Homework Help: Science