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June 25, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
A solution of concentrated NaOH is 16.4 M. If the density of the solution is 1.43 g/mL what is the percent by mass NaOH?
Thursday, May 12, 2016 by Olivia

Chemistry
A solution is 25% by mass calcium nitrate and has a density of 1.21 g/mL what is the molarity?
Thursday, May 12, 2016 by Adrian

Chemistry
A current of 2 Amperes is past for 30minutes. Calculate the mass of sodium and the mass of copper deposited.
Thursday, May 12, 2016 by Anna

Chemistry
45.1 grams of Sodium Chloride is combined with 72.3 grams of barium phosphate. Balance the following equation NaCl + Ba3(PO4)2 --> Na3PO4 + BaCl2 How many grams of Barium dichloride will be produced?
Thursday, May 12, 2016 by Adam / DrBob222

chemistry
1. A large salt crystal having a volume of 56 cm3 and a density of 2.17 g/cm3 was dissolved in to sufficient water to make 375 mL of solution. What is the salt concentration in the solution as g/L?
Thursday, May 12, 2016 by Montie Stengel

Chemistry
would it be possible to dissolve 50g of sodium chloride in 100g of water? explain.
Thursday, May 12, 2016 by Kinge

Chemistry
Insoluble silver carbonate, Ag2CO3(s), forms in the following balanced chemical reaction: 2AgNO3(aq) + K2CO3(aq) = Ag2CO3(s) + 2KNO3(aq). What mass of silver nitrate, 2AgNO3(aq), reacts with 25.0 g of potassium carbonate,K2CO3(aq),if there is at least 5.5 g of silver nitrate ...
Thursday, May 12, 2016 by Gale

chemistry
The H3O+ ion concentration in water is 1/10000000 molar.The degree of ionisation of H2O is? If given molarity of pure water is 55.5Molar.
Thursday, May 12, 2016 by monika

science-chemistry
The extent of ionisation in a 0.75M solution of a monoprotic acid is 0.040. calculate Ka
Thursday, May 12, 2016 by shelagh

Chemistry
how many atoms of S are in 9.2 moles of Na(SO4)2?
Thursday, May 12, 2016 by Emergent help please!!

Chemistry
A 100g sample of water absorbs 308kJ of heat. If the water was initially at -10 degrees Celsius, what is its final temperature?
Thursday, May 12, 2016 by Homework Help:

Chemistry
Activation energy is____ the heat released in a reaction*** the energy barrier between reactants and products the energy given off when reactants collide generally very high for a reaction that takes place rapidly
Thursday, May 12, 2016 by Annamarie

chemistry
white powder of calcium oxide is added to beaker containing water?
Thursday, May 12, 2016 by kiranmai

chemistry
A large salt crystal having a volume of 56 cm3 and a density of 2.17 g/cm3 was dissolved in to sufficient water to make 375 mL of solution. What is the salt concentration in the solution as g/L?
Thursday, May 12, 2016 by chrissy

Chemistry
Given the following information: C(s) à C(g), H = +715 kJmol-1 Cl2(g) à 2Cl(g), H = +242 kJmol-1 C(s) + 2Cl2(g) à CCl4(g), H = -135.5 kJmol-1 Calculate the average bond dissociation enthalpy of a C-Cl bond.
Thursday, May 12, 2016 by C

chemistry
the solubility of Mg(OH)2 at 25C is4.6x10^-3 g/100cm3? what is the solubility product of M g(OH)2?
Thursday, May 12, 2016 by ali

Chemistry
A naturally occuring sample of copper consists of 69.2% of Cu63 and 30.8% of Cu65.The relative atomic mass of Cu63 is 62.93 and that of Cu65 is 64.93.Find the atomic mass of a naturally occuring sample of copper.
Thursday, May 12, 2016 by Bhagavatula yogiraj

chemistry
Calculate the temperature in kelvin of a 2.5 mol sample at 8.3 atm in 45 L. Give your answer to 2 sig figs. Which equation do I use to calculate temperature?
Thursday, May 12, 2016 by Kierstin

Chemistry (Stoich)
13.In a study of rust-removing solutions, 27.8 mL of 0.115 mol/L phosphoric acid reacts completely with 0.245 mol/L sodium hydroxide. Predict the minimum volume of sodium hydroxide required for this reaction? 3 NaOH + H3Po4 = 3H20 + Na3PO4 (27.8 ml)(0.115) = 0.003197 mol H3Po4...
Thursday, May 12, 2016 by Studying

Chemistry
Calculate the pH of a buffered solution prepared from 0.25 mol KF and 0.75 HF after the addition of 0.05 mol of NaOH (assume a 1.0 L volume of solution) I get that i need to use two seperate ice tables, but i don't really understand how to go about doing that?
Thursday, May 12, 2016 by Megan

Chemistry
How do can you find the difference between these acids/bases with only one indicator? We have 0.1M NaOH, H2SO4, HCl, AlCl3, and Na2CO3. We know the pH of all the solutions (AlCl3 = 2.9, H2SO4 = 0.7, HCl = 1, Na2CO3 = 11.8, NaOH = 13). We only can use 1 indicator to determine ...
Wednesday, May 11, 2016 by Jaime

Chemistry
What is the molarity of 10g of H2SO4 in 100ml of water?
Wednesday, May 11, 2016 by Deysi

Chemistry
If 27 grams of propane react with 88 grams of oxygen to make carbon dioxide and water then how many grams of carbon dioxide can be made?
Wednesday, May 11, 2016 by Jessica

Chemistry
The human body is said to contain approximately 50.0 grams of DNA in the entire body. If the number of nucleotides in one strand of DNA is approximately 3.0 x 10^6, and the average molar mass of a nucleotide is 327 g/mole, what is the average molar mass of an entire DNA double...
Wednesday, May 11, 2016 by Merp

chemistry
What mass of water is produced when 0.1 moles of C2H6 is reacted with 0.1 moles of O2?
Wednesday, May 11, 2016 by PLEASE HELP ME

chemistry
The vapour pressure of pure water at 760 mm at 25 degree celcius. The vapour of solution containing 1m solution of glucose will be.
Wednesday, May 11, 2016 by munaf

Chemistry
5.88 moles of nitrogen and 16.2 moles of oxygen are mixed until the equilibrium is established, 11.28 moles of nitric oxide are formed calculate the value of equilibrium constant
Wednesday, May 11, 2016 by Anon

Chemistry
The human body is said to contain approximately 50.0 grams of DNA in the entire body. If the number of nucleotides in ONE STRAND of DNA is approximately 3.0 x 106, and the average molar mass of a nucleotide is 327 g/mol, what is the average molar mass of an entire DNA double ...
Wednesday, May 11, 2016 by KS

Chemistry
if 40.0 ml of 11.25 M KNO3 is used to make a 7.55 L aqueous solution, what is the molarity of the solution
Wednesday, May 11, 2016 by Reilly

chemistry
what will haprn if ammonium chloride solution is used to standardize potassium tetraoxamaganate VII solution instead of ammonium iron II sulphate
Wednesday, May 11, 2016 by samuel

Chemistry
2ZnS + 3O2 -> 2ZnO + 2SO2 If 1000kg of ZnS is oxidised, what amount (in moles) and volume (in litres) of SO2 is produced (assuming that gas is at STP)
Wednesday, May 11, 2016 by Casey

Chemistry - Order of Bond Polarity
Hi I am having a bit of trouble with this question CCl4 is confusing me: Qu)Rank the following compounds in order of bond polarity; HF, CH4, H2O, H2S, CCl4 Asw)lowest to highest bond polarity: CH4, CCl4, H2S, H2O, HF Is this correct? Thanks!
Wednesday, May 11, 2016 by Anonymous

chemistry
need help drawing an electrochemical cell that could be used to plate zinc onto other metals.labeling cathode and anode, and reactions that occur.
Wednesday, May 11, 2016 by anonymous

Chemistry
How many grams of perchloric acid are dissolved into 3.86 L of water, if the pH of the solution is 4.03.
Wednesday, May 11, 2016 by Jose

Chemistry
what is the osmotic pressure produced by a 1.20M glucose (C6H12O6) solution at 25 degree celsuis?
Wednesday, May 11, 2016 by Elsie

Chemistry
what is the osmotic pressure produced by a 1.20M glucose (CH12O6) solution at 25 degree
Wednesday, May 11, 2016 by Elsie

Chemistry
When chromium has 26 electrons, how many neutrons and protons does it have and what is it's standard notation
Tuesday, May 10, 2016 by Chris

Chemistry
How many grams of sodium sulfate na2so4 must be added to make 500ml of a 12.5 M sodium sulfate solution
Tuesday, May 10, 2016 by Jessie

Chemistry
I'm sorry here is another I do not understand. How do you find out exactly how much of a solution you would need to completely precipitate another compound in the reaction? We can precipitate out solid lead(II) iodide from an aqueous lead(II) nitrate solution by adding ...
Tuesday, May 10, 2016 by Kierstin

Chemistry
20. What is the molecular formula for alkane, alkenes and alkynes? 15.What happens to a reaction at equilibrium when more reactant is added to the system?
Tuesday, May 10, 2016 by BLAH

Chemistry
We can precipitate out solid lead(II) iodide from an aqueous lead(II) nitrate solution by adding potassium iodide. If we have 500. mL of 0.632 M lead(II) nitrate solution and add excess potassium iodide, how much solid lead(II) iodide will form (in grams)? 2 KI(aq) + Pb(NO3)2(...
Tuesday, May 10, 2016 by Kierstin

chemistry
The total mass of DNA in the body is 50.0 g. If the number of nucleotides in ONE STRAND of DNA is approximately 3.0 x 106, and the average length of a single nucleotide is 0.34 nm, what is the length (in km) of one strand of DNA when it is stretched out to its maximum length (...
Tuesday, May 10, 2016 by jenna

chemistry
If the average volume of all the blood in a human body is 4700 mL, what is the molarity of DNA in the human blood system?
Tuesday, May 10, 2016 by jenna

chemistry
The human body is said to contain approximately 50.0 grams of DNA in the entire body. If the number of nucleotides in ONE STRAND of DNA is approximately 3.0 x 106, and the average molar mass of a nucleotide is 327 g/mol, what is the average molar mass of an entire DNA double ...
Tuesday, May 10, 2016 by jenna

Chemistry
would someone be willing to help me fill out my study guide
Tuesday, May 10, 2016 by BLAH

Chemistry
When I push on my refrigerator, there is a force acting on it that wasn't there before. That means it should be experiencing an unbalanced force and begin to move. Why doesn't it?
Tuesday, May 10, 2016 by Jaz

Chemistry
A buffer system contains 0.30 M NH4+ and 0.15 M NH3. pKa of NH4+ is 9.25. How many moles of NaOH must be added to 1.00 L of this solution to increase the pH to 9.25? Hint: What is the (NH3) / (NH4+) when the pH=pKa?
Tuesday, May 10, 2016 by Ally

chemistry
when zinc graurles are dipped in copper sulphate solution write balance equation?
Tuesday, May 10, 2016 by swati

chemistry
Henry's law constant for N2 and O2 is 1.6 *10^-6and 8.77*10^-7 molal/mm Hg at 298k.Air has 78 mole percentage N2 and 21 mole percentage O2.at atmospheric pressure the ratio of solubility of N2 and O2 in water is?
Tuesday, May 10, 2016 by Rahul

Chemistry
The nitric acid was purchased as a solution that has 70% HNO3. That volume (mL) of this solution is necessary for preparing 250 mL Solution 2.0 mol L-1? The density of HNO3 (aq) 70% is 1.42 g cm-3
Tuesday, May 10, 2016 by Adam

chemistry 12u
how do i calculate this.. a solution of nitrous acid has a pH of 2.73 what is the [H3O+] ?
Tuesday, May 10, 2016 by julie

chemistry
Cu2+ + 2e- -> Cu Oxidation reaction Cu -> Cu2+ + 2e Reduction Reaction Do I have these right, or are they backwards?
Monday, May 9, 2016 by kat

Chemistry
How many grams of sucrose will be necessary to prepare 300 ml of a 5% solution of sucrose (342.0 g/mol)
Monday, May 9, 2016 by Adam

Chemistry
how many grams of AlCl3 is produced if 15.5 grams of Al are reacted with excess Cl2 gas? 2Al + 3Cl2 > 2AlCl3
Monday, May 9, 2016 by Emily

Chemistry
You want to neutralize 6 mol of sulfuric acid with 6.0 M sodium hydroxide. How much 6.0 M sodium hydroxide must you add to react exactly with the sulfuric acid? 2NaOH(aq)+H2SO4(aq)-->2H2O(l)+Na2SO4(​aq) 2 moles sodium hydroxide for every 1 mol sulfuric acid. which ...
Monday, May 9, 2016 by Kierstin

chemistry
The basicity of tetraoxosulphate(6) is 2. explain this statement with an equation showing the reaction between the acid and potassium hydroxide
Monday, May 9, 2016 by Ayibadenyifa

Chemistry
The reaction of methyl-benzene with HNO3 in the presence of catalyst will provide what main compound?
Monday, May 9, 2016 by David

chemistry
how many unpaired electrons are in this complex? Ni(en)2(CN)2 where en is the neutral ethylenediamine and CN is cyanide as the counter ion, I want to say there are no unpaired e- but I'd like a check
Monday, May 9, 2016 by Anonymous

Chemistry
What are the molecular formula for: 3-methylpentanoic acid Cis-2-propyl-2-hexane N-methylpropanamine N-methylhexan-3-amine
Sunday, May 8, 2016 by Rose

chemistry
The measured density oe He at NTP is 0.1784g/l.what is the weight of one mole?
Sunday, May 8, 2016 by dev

chemistry
You have a solution of 12.0 M HCl. You need 36.5 g of hydrochloric acid for a reaction in your chemistry lab. How many mL of solution must you use?
Sunday, May 8, 2016 by Nur

Chemistry
Caso4+naoh
Sunday, May 8, 2016 by Raju

Chemistry
Sulfamethoxazole has the molecular formula C10H11N3O3S. 10.0 g of tablets containing sulfamethoxazole and trimethoprim were crushed and dissolved in water. A strong oxidising agent was added, which converted all the sulfur in the sulfamethoxazole into sulfate ions. Following ...
Sunday, May 8, 2016 by M

Chemistry- Dr.Bob222
What is the solubility of AgCl in 10 M NH3? The Kf of Ag(NH3)2+ from AgCl(s) in aqueous NH3 is 0.0031, which is for the balanced reaction shown below. AgCl(s) + 2 NH3(aq) → Ag(NH3)2+(aq) + Cl-(aq) Work: Ksp = x^2 /(2x+10)^2 = 1.8 x 10^-10 Now I am confused....... At ...
Sunday, May 8, 2016 by Nevaeh

Chemistry- Dr.Bob222
I do not quiet understand what you said. Could you show your work. What is the solubility of AgCl in 10 M NH3? The Kf of Ag(NH3)2+ from AgCl(s) in aqueous NH3 is 0.0031, which is for the balanced reaction shown below. AgCl(s) + 2 NH3(aq) → Ag(NH3)2+(aq) + Cl-(aq)
Saturday, May 7, 2016 by Nevaeh

Chemistry- Dr.Bob222
Question 2 What is the solubility of AgCl in 10 M NH3? The Kf of Ag(NH3)2+ from AgCl(s) in aqueous NH3 is 0.0031, which is for the balanced reaction shown below. AgCl(s) + 2 NH3(aq) → Ag(NH3)2+(aq) + Cl-(aq) Is the answer 0.557 M?
Saturday, May 7, 2016 by Nevaeh

Chemistry
You want to neutralize 6 mol of sulfuric acid with 6.0 M sodium hydroxide. How much 6.0 M sodium hydroxide must you add to react exactly with the sulfuric acid? 2NaOH(aq)+H2SO4(aq)-->2H2O(l)+Na2SO4(​aq) 2 moles sodium hydroxide for every 1 mol sulfuric acid. I do not...
Saturday, May 7, 2016 by Kierstin

chemistry
A 15.0 g sample consisting of a mixture of silver nitrate and sodium nitrate is dissolved in water. This aqueous mixture then reacts with aqueous potassium chloride to form 3.97 g of solid. Calculate the percent by mass of silver nitrate in the first mixture.
Saturday, May 7, 2016 by Chuck

Chemistry
How do you transform an alcohol into an alkene? The example I need help with is: What are the reagents to transform 1,2-dimethyl-propanol to 4,5-dimethyl-2-hexene? This must be done in two steps.
Saturday, May 7, 2016 by Alice

Chemistry
A sample of 20.0 g of chlorine gas at 15 degrees Celsius occupies a volume of 5.0 L. What is the pressure of the gas?
Saturday, May 7, 2016 by Lauren

Chemistry
What are the possible reagents needs to transform 1-butene to 2-butene? This can be done in two steps.
Saturday, May 7, 2016 by Alice

Chemistry
What volume of oxygen gas is needed for the complete combustion of 4.00 L of ethane gas, C2H6? Assume that the temperature and pressure of the reactants are the same.
Saturday, May 7, 2016 by Lauren

Chemistry
What will happen if 2NaCl+CaCO3+SiO2 heated at 1200°C till it turns into liquid form.
Saturday, May 7, 2016 by Ashvin

Chemistry
0.75 L of a 48.5 %V/V methanol solution is diluted to make 5.60 L of solution. What is the final concentration of this solution?
Saturday, May 7, 2016 by JavaCompiler

Chemistry
How would one work through this problem? -Calculate the number of liters of 1.25M solution that can be made from 6.400g of barium nitrate. - I know that it's just stoichiometry, but I'm confused. The formula for molarity is the number of moles of the solute divided by ...
Saturday, May 7, 2016 by Charlie

Chemistry
At 25 °C, an aqueous solution has an equilibrium concentration of 0.00147 M for a generic cation, A (aq), and 0.000735 M for a generic anion, B2–(aq). What is the equilibrium constant, Ksp, of the generic salt A2B(s)?
Friday, May 6, 2016 by Jordan

chemistry
How many milliters of a 6.ooM HCl solution are required to react with 21.0 grams of Mg? I'm so confused. I know how to get the Molar mass of Mg and HCl but, does that even matter here?
Friday, May 6, 2016 by christine

Chemistry
What is the molar mass of toluene if 0.85 g of toluene depresses the freezing point of 100 g of benzene by 0.47 degrees celsius? Kf= 5.12 C/m
Friday, May 6, 2016 by Matthew

chemistry
calculate the number of grams of Al2S3 which can be prepared by the reaction of 20g of Al and 30gm of sulphur. how much the non_limiting reactant in excess?
Friday, May 6, 2016 by Ahsan

chemistry
C3H8+5 o2 - 3CO2 +4H2O the reaction If I have 56.7 liters of o2 reacted, how many liters of H2O were produced?
Friday, May 6, 2016 by kia

chemistry
calculate the number of moles of Mg in 0.12g(relative mass of Mg=24)
Thursday, May 5, 2016 by jan

Chemistry
DrBobb22 Calcule the concentrations of Cd^+2 , [Cd(CN)4^-2] and CN^- at equilibrium, when 0.42 moles of Cd(NO3)2 dissolves in 1 L of 2.50 M NaCN Kf for Cd(CN)4^-2 is 7.1x10^16
Thursday, May 5, 2016 by David

Chemistry
DrBobb22 Calcule the concentrations of Cd^+2 , [Cd(CN)4^-2] and CN^- at equilibrium, when 0.42 moles of Cd(NO3)2 dissolves in 1 L of 2.50 M NaCN Kf for Cd(CN)4^-2 Help!
Thursday, May 5, 2016 by David

Chemistry
Calculate the concentrations of Cd+2 , Cd(CN)4^-2 and CN at equilibrium when dissolvs 0.42 moles of Cd(NO3)2 (2.50 mol/L) Kf for Cd(NO3)2 = 7,1x10^16.
Thursday, May 5, 2016 by David

chemistry
im having trouble understanding this hw question, okay here's the question: A 0.326 8-g unknown containing Pb(CH3CHOHCO2)2 (lead lactate, FM 385.3) plus inert material was electrolyzed to produce 0.111 1 g of PbO2 (FM 239.2). Was the PbO2 deposited at the anode or at the ...
Thursday, May 5, 2016 by Anonymous

Chemistry
What volume in ml of 0.500 M silver nitrate is required to completely react with 25.0 ml of 1.5 M calcium chloride?
Thursday, May 5, 2016 by David

chemistry
35.0 mL of an aqueous solution of HNO3 of unknown concentration is titrated with a standard solution made up of 0.453 m NaOH
Thursday, May 5, 2016 by diala toulany

chemistry
calculate the poh of 1 dm^3 of naoh solution containing 4 g of sodium hydroxide
Thursday, May 5, 2016 by Anonymous

Chemistry
What is the maximum mass(g) of KCL that can be added to 1.00L of a 0.0100 M lead(ii) chloride solution without causing any precipitation of PbCl2? Assume the additional KCl does not affect the volume of the solution. For, PbCl2, Ksp=1.6x10^-5 Personally I'm at a loss here...
Thursday, May 5, 2016 by Alex

chemistry
Problem 3 A publication this year in the journal Yeast (who’d have thought!) by a Scottish group described their development of a spectrometric procedure to monitor the concentration of glucose, ethanol, biomass, and protein content in a vat during the production of Baker...
Thursday, May 5, 2016 by asery

Chemistry
An indicator is what type of compound? a. reducing agent b. oxidizing agent c. weak base or acid d. strong base or acid
Wednesday, May 4, 2016 by benji

Chemistry
What amount of ammonium sulfate is produced by the reaction of 8.48g of ammonia with 24.50g sulfuric acid?
Wednesday, May 4, 2016 by benji

Chemistry
3 x 10^23 molecules of element Z have a mass of 38 g. What is the mass of 1 mole?
Wednesday, May 4, 2016 by Monica

Chemistry
What is the oxidation state of chromium in cr2o7^-2
Wednesday, May 4, 2016 by Julia

Chemistry
What is the pH of a solution prepared by mixing 50.0 mL of 0.010 mol/L HCl(aq) and 50.0 mL of 0.010 mol/L Ca(OH)2(aq)? Assume the temperature is 25 degrees Celsius. Additional information given: Kw = 1.0×10^−14 at 25 degrees Celsius. The possible answers are: A) 2....
Wednesday, May 4, 2016 by allie

health science chemistry
How many ml of water should be added to 20.0 ml of a stock of 12.0 M HCl solution to make 1.50 M HCl ?assume that the volumes are additive.
Wednesday, May 4, 2016 by konja

Chemistry
If an ideal gas write the balances equation for the combination of magnesium and oxygen to form magnesium oxide, MgO.
Wednesday, May 4, 2016 by Jaila

Chemistry
Complete and balance the precipitation reaction. Include physical states in your answer. CuCI2(aq)+Na2CO3(aq)
Wednesday, May 4, 2016 by Tiara

Chemistry
Calculate the ph of a solution that is 0.157m HCI?
Wednesday, May 4, 2016 by James

Chemistry
How many grams of solute are present in 795 ml of 0.130m KBr?
Wednesday, May 4, 2016 by Ray

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Homework Help: Science