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August 30, 2015

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry 12
Hi, I did the acid-base titration lab with HCl and 0.5M NaOH. I need to calculate the moles of NaOH from molarity of NaOH and the average volume used. My English isn't good but is it asking me to find the moles of NaOH using the molarity of NaOH and the average volume used...
Tuesday, June 2, 2015 by Kim

chemistry
TWO IDENTICAL mano METERS ARE FILLED WITH MERCURY. THE mano METERS ARE PLACED IN A CLOSED PRESSURIZED BOX CONTAINING AIR AT 1,000 TORR PRESSURE. ONE manometer CONTAINS GAS a, AND THE OTHER GAS B. WHAT IS THE DIFFERENCE BETWEEN THE PRESSURES OF THE TWO GASES? THE DENSITY IS 13....
Tuesday, June 2, 2015 by PLEASE HELP!!

Chemistry
How many grams of NaCl will you need to mix 200ml of a 2.3M solution?
Tuesday, June 2, 2015 by Dennese

chemistry
TWO IDENTICAL mano METERS ARE FILLED WITH MERCURY. THE mano METERS ARE PLACED IN A CLOSED PRESSURIZED BOX CONTAINING AIR AT 1,000 TORR PRESSURE. ONE manometer CONTAINS GAS a, AND THE OTHER GAS B. WHAT IS THE DIFFERENCE BETWEEN THE PRESSURES OF THE TWO GASES? THE DENSITY IS 13....
Tuesday, June 2, 2015 by Joseph

Chemistry
The density of pure diamond is 3.5 g/cm^3. The mass of a diamond is 0.25 g.Calculate its volume.
Tuesday, June 2, 2015 by jessica

CHEMISTRY
calculate the volume of air required for complete combustion of 1m^3 of gaseous fuel having the combustion:CO=46%,CH4=10%,H2=4%,C2H2=2.0​%,N2=1% and the remaining being CO2
Tuesday, June 2, 2015 by Anonymous

Chemistry
What is the mass of a 4 kg object, A. On the earth (g=-10 m/s/s) B. On the moon (g=-2 m/s/s)
Monday, June 1, 2015 by Clarissa

Chemistry
50cm'3 of sulphur (iv) oxide were produced at s.t.p when some quantity of powdered sulphur were burnt in excess oxygen.state the equation for the reaction Ans S+O2g-2SO2
Monday, June 1, 2015 by Anonymous

chemistry
'the vapour density of certain gas x is 4 times that of y the molecular mass of x is m the molecular mass of y is ?'
Monday, June 1, 2015 by breera

chemistry
A sealed cylinder of gas contains nitrogen gas at 1.00 ✕ 103 kPa pressure and a temperature of 28°C. The cylinder is left in the sun, and the temperature of the gas increases to 50.°C. What is the new pressure in the cylinder?
Monday, June 1, 2015 by becky

Chemistry
What would have happened if Rutherford shot negative particles instead of positive particles in his gold-foil experiment? What would have happened if the nucleus in the gold-foil was actually negative, rather than positive, in his experiment?
Monday, June 1, 2015 by Madi

chemistry
if you are given 25 grams of H2O how many grams of H2 can you produce??? i am lost... help
Monday, June 1, 2015 by jojo

chemistry
how many moles of hydrogen would be produced from 16 moles of Na?/ xH2mol/16Namol??/
Monday, June 1, 2015 by jojo

Chemistry
A 1.00 kg piece of aluminum metal at 80 degrees Celsius is placed in water that is 25 degrees Celsius. How much water is needed to cool the aluminum to 65 degrees? I'm stuck as where to start with this.
Monday, June 1, 2015 by Bella

chemistry
is the formation of an aqueous solution with water, a physical or chemical property? physical..... because the substance doesn't change.....
Sunday, May 31, 2015 by jojo

Chemistry
My Question is: Commercial vinegar usually has a concentration of 5%, per volume. Calculate the [H3O+], if the density of acetic acid is 1.051 g/mL. What I did was: mass = V * density mass = 0.05 * 1.051 = 0.05 g moles = grams/molar mass = 0.05/60.05 = 8.3 * 10^-4 M = moles/V...
Sunday, May 31, 2015 by Kibito

chemistry
how many significant figures are in the measurement 0.002 ml? 2??
Sunday, May 31, 2015 by jojo

chemistry
what part of the meniscus must be read to accurately record the volume of a liquid in a graduated cylinder??? the lowest of the bubble?
Sunday, May 31, 2015 by jojo

chemistry
if 15.95 g dissolves in 100ml of water what will be the solubility in g/ml expressed to the proper number of significant figures?/ 15.95/100 =.0595
Sunday, May 31, 2015 by jojo

Chemistry
NCl3, SiCl4, AsCl3, SCl2, PCl3 order them in terms of increasing bond polarity NCl3<SCl2<PCl3<SiCl4<AsCl3 this Is what I have it says "Your answer appears to contain an incorrect substance" I don't see any incorrect substances unless I'm blind??
Sunday, May 31, 2015 by Asher

Chemistry
What is the difference between a square pyramidal and a trigonal bipyramidal? I know that the square has a square base and that trigonal bipyramidals have 5 atoms bonded to it but when I have questions that have 5 atoms bonded they end up being squares instead of trigonals. ...
Sunday, May 31, 2015 by Asher

Chemistry
Tap water that contains Cl− at a concentration of 50 ppm is used to prepare a 0.100 mol/L AgNO3 solution. Does a precipitate form? How much? I dont know how to find out how much precipitate will form but a precipitate will form based on my calculations 50 ppm 0.0014 mol/...
Sunday, May 31, 2015 by Rez

chemistry
What mass of copper will be deposited by a current of 7.89?
Sunday, May 31, 2015 by solomon

nuclear chemistry
Determine the nuclear binding energy for Pd-101. atomic mass of Pd-101=100.908287 g/mol.
Sunday, May 31, 2015 by Anonymous

nuclear chemistry
determine the nuclear binding energy for Ir-187. Atomic mass of Ir-187=187.958830 g/mol (per nucleon) dE=dmc(^2) mass of proton= 1.00728 amu mass of neutron=1.00866 amu
Sunday, May 31, 2015 by Anonymous

nuclear chemistry
determine the nuclear binding energy for Ir-187. Atomic mass of Ir-187=187.958830 g/mol (per nucleon) dE=dmc(^2) mass of proton= 1.00728 amu mass of neutron=1.00866 amu
Sunday, May 31, 2015 by Anonymous

Chemistry
20.00mL of a 1.100x 10^-4 mol/L Pb(NO3)2 is mixed with 80.00mL of 4.45010^-2 mol/L CaI2. Will a precipitate form? for the Ksp i got 2.7x10^-8 and im not sure if its right or not this is what i did [Pb2+] = (1.1x10^-4 mol/L x 0.02L)/(0.02L + 0.08L) = 2.2x10^-5 mol/L [I-] = (4....
Sunday, May 31, 2015 by Rez

Chemistry
What mass of carbon dioxide is released by heating 2 moles of calcium carbonate?
Saturday, May 30, 2015 by Apphia Lord

chemistry
If I contain 3 moles of gas in a container with a volume of 60 liters and at temperature of 400 K, what is the pressure inside the container? Ideal Gas Law: PV=nRT I know I'm given the volume, temperature, and numbers of moles of gas, but how do I know which ideal gas ...
Saturday, May 30, 2015 by kara

Chemistry
A neutralisa tionreaction occurs when 120 millilitres of 0.5 mol/l lithium hydroxide(aq) and 160 millilitres of 0.375 mol/l and HNO3(aq) are mixed in a insulated Cup. initially the solutions are at the same temperature. If the highest temperature reached during the mixing with...
Saturday, May 30, 2015 by Fay

chemistry
Explain the following quote with your understanding of the concept of gas mixtures (Ch. 10 concepts) and the composition of “common air” (i.e. the air in the atmosphere). Inflammable air is hydrogen. “By the experiments... it appeared that when inflammable air ...
Saturday, May 30, 2015 by helen

chemistry
how many grams of cacl2 are needed to prepare 6.00L of a 0.400M CaCl2 solution
Saturday, May 30, 2015 by jen

Chemistry
Write 3–4 sentences to describe how coupling reactions are used to drive an unfavorable chemical reaction
Friday, May 29, 2015 by Madison

chemistry
Describe the difference in intermolecular forces between the two molecules. How does this affect the properties of the substance first one molecule is made up of H3C,OH,CH3, and another CH3. The second molecule is made up of H3C,O,OH3, and CH3.
Friday, May 29, 2015 by Ashley

chemistry
What is the density of propane gas, C3H8, when measured at 18 grade celcius and 744 torr pressure?
Friday, May 29, 2015 by Dion

general chemistry
Explain the following quote with your understanding of the concept of gas mixtures (Ch. 10 concepts) and the composition of “common air” (i.e. the air in the atmosphere). Inflammable air is hydrogen. “By the experiments... it appeared that when inflammable air ...
Friday, May 29, 2015 by jess

chemistry
Explain the following quote with your understanding of the concept of gas mixtures (Ch. 10 concepts) and the composition of “common air” (i.e. the air in the atmosphere). Inflammable air is hydrogen. “By the experiments... it appeared that when inflammable air ...
Friday, May 29, 2015 by Brittani

Chemistry
If 60% of a first order reaction was completed in 60 minutes, 50% of the same reaction would be completed in approximately
Friday, May 29, 2015 by sam

Chemistry
b) Write 3 – 4 sentences to describe the first law of thermodynamics and use it to describe what happens when two substances at different temperatures come in contact with each other. I know the first law states that "energy can neither be created nor ...
Friday, May 29, 2015 by Madison

chemistry
How can I change ca(hco3)2+cl(aq)=cacl2(aq) + co2(g) + h2O in to ironic equation?
Thursday, May 28, 2015 by marcellino

Chemistry
To 20 mL of .2 m nitric acid are added successive amounts of a base of unknown concentration. Neutrality is reached after the addition of 40 mL of the base. What was the OH of the original base solution? assume that it was 100% ionized.
Thursday, May 28, 2015 by Ian

chemistry
50cm3 of hydrogen is collected over water at 17 degree celsius and 750 mm Hg pressure.Calculate the volume of dry gas at S.T.P.The water vapour pressure at 17 degree celsius is 14 mm Hg?
Thursday, May 28, 2015 by j

chemistry
CHEMICAL KINETICS The rate of reaction 2N₂O5->4NO₂+O₂ can be written in three ways -d[N₂O5]/dt= k[N₂O5] d[NO₂]/dt= k'[N₂O5] d[O₂]/dt =k"[N₂O5] The relationship between k and k' and between k and k" are ?
Thursday, May 28, 2015 by tanya

Chemistry
A 26 L flask at 273 K and 17 Torr contains nitrogen . What mass of the nitrogen is present? Answerand units of g.
Thursday, May 28, 2015 by Anonymous

Chemistry
How much heat is absorbed when 60.0h of ammonia is vaporized ?
Thursday, May 28, 2015 by Me

CHEMISTRY
CHEMICAL KINETICS The rate of reaction 2N₂O5->4NO₂+O₂ can be written in three ways -d[N₂O5]/dt= k[N₂O5] d[NO₂]/dt= k'[N₂O5] d[O₂]/dt =k"[N₂O5] The relationship between k and k' and between k and k" are ?
Thursday, May 28, 2015 by sam

chemistry
14g of lithium hydroxide dissolves in 500cm^3 of water.in titration ,30cm^3 is used to neutralise sulphuric acid of 0,2mol.dm^-3 how do i calculate (a)concentation of a base
Thursday, May 28, 2015 by jeremy

chemistry
24,8% of potassium ,34,77% of Mn,40,5% of oxygen how do i find the emperical formular thanks in advance
Thursday, May 28, 2015 by jennifer

chemistry
14g of lithium hydroxide dissolves in 500cm^3 of water.in titration ,300m^3 is used to neutralise sulphuric acid of 0,2mol.dm^-3 how do i calculate (a)concentation of a base and calculate for (c)volume of the acid and (c)which mass of Alkaline was used thanks in advance.
Thursday, May 28, 2015 by drBOB222

Chemistry
25g of NH3 is mixed with 4 moles of O2 in given reaction. 4NH3(g)+5O2(g)-->4NO(g)+6H2O(1) <--- what mass of NO is formed? What mass of H2O is formed?
Thursday, May 28, 2015 by Erawd

Chemistry
A balloon holds 27.8 kg of helium. What is the volume of the balloon if the pressure is 0.97 atm and the temperature is 24 °C
Wednesday, May 27, 2015 by Yakima valley communtiy college

Chemistry
What mass of helium gas is needed to pressurize a 98.0 L tank to 165 atm at 21 °C? What mass of oxygen gas would be needed to pressurize a similar tank to the same specifications
Wednesday, May 27, 2015 by Yakima valley communtiy college

Chemistry
How many grams of KBr are contained in 200 mL of a 0.310M KBr solution?
Wednesday, May 27, 2015 by Lauren

Chemistry
Calculate the sodium ion concentration when 50.0 mL of 2.0 M sodium carbonate is added to 100.0 mL of 3.0 M sodium bicarbonate.
Wednesday, May 27, 2015 by Will

Chemistry
An atom has 98 protons and 151 neutrons. If it undergoes alpha decay, what are the number of protons and neutrons, respectively, in the daughter nucleus?
Wednesday, May 27, 2015 by Clarissa

Chemistry
A 50 ml sample of .150M Ch3CooH is titrations with .150 M NaOh solution. Calculate the ph after the following volumes of base have been added: 49 ml, 51ml
Wednesday, May 27, 2015 by Bob

chemistry
14g of lithium hydroxide dissolves in 500cm^3 of water.in titration ,300m7^3 is used to neutralise sulphuric acid of 0,2mol.dm^-3 how do i calculate (a)concentation of a base and calculate for (c)volume of the acid and (c)which mass of Alkaline was used thanks in advance.
Wednesday, May 27, 2015 by kem

Chemistry
If air is 20% oxygen, and the reaction is 2C2H2 + 5O2 --> 4CO2 + 2H2O, What volume of oxygen would be needed to completely burn 1.00 L of acetylene (C2H2)? I got 2.50 L but I'm not sure it's right. What volume of air would be needed to completely burn 1.00 L of ...
Wednesday, May 27, 2015 by anonymous

chemistry
In a zero order reaction ,20% of the reaction complete in 10s .How much time it will take to complete 50% of the reaction?
Wednesday, May 27, 2015 by tanya

chemistry- titration
Once you have calculated your Ka value, use the data to find the concentration of the unknown acids. Vol. of acid solution=25mL concentration of NaOH used = 1M Buffer (pH) = 8.35 at 11.5mL 1/2 11.5=5.75mL which is a pH of 3.58 I did pH=pKa + log(acid/base) to find the pKa pH=...
Wednesday, May 27, 2015 by Amber

chemistry
109% of carbon,18,2% of hydrogen and 73% of oxygen how do i calculate emperical formular?
Wednesday, May 27, 2015 by happy

chemistry
A|A+3(0.1)||B+2(0.01m)|B GIVEN E°A|A+3=0.75v E°B|B+2=0.45v
Wednesday, May 27, 2015 by tanya

Chemistry
Hydrazene can be used in fuel cell N2H4(aq)+o2(g)->N2(g)+2H2O(l) IfΔG°for this reaction is -600kj what will be the E°for the cell?
Wednesday, May 27, 2015 by tanya

chemistry
Balance the redox reaction of eq. Cu2S + SO4(-2) gives CuO + SO2 (Acidic )
Wednesday, May 27, 2015 by Anonymous

Chemistry
Determine the entropy change when 1.80 mol of HBr(g) condenses at atmospheric pressure? I got that DeltaS fus = 12.922J/(k*mol) Delta S Vapour = 93.475J/(K*mol) the only thing I don't get is the entropy change when 1.80 mol of HBr(g) condenses at atmospheric pressure. How ...
Wednesday, May 27, 2015 by Lola

college chemistry
How many calories are required to change 259 g of ice at 0 °C to steam at 100 °C?
Tuesday, May 26, 2015 by Mark

Chemistry
Mount McKinley in Alaska is the tallest peak in North America with a summit at 20,320 ft, or 6194 m. It is also known as Denali, meaning "the high one" in the native Koyukon Athabaskan language. The average atmospheric pressure at the top of Denali is approximately ...
Tuesday, May 26, 2015 by Mark

Chemistry
If 125 g of ice at 0.0°C is added to 1.95 L of water at 90 °C, what is the final temperature of the mixture?
Tuesday, May 26, 2015 by Mark

Chemistry
How many joules of energy are needed to change 114 g of water at 16.5°C to steam at 100°C?
Tuesday, May 26, 2015 by Mark

Chemistry
When 1 mole of ethylene (C2H4) is burned at constant pressure, 1410 kJ of energy is released as heat. Calculate dH for a process in which 10.0 g of ethylene is burned at constant pressure.
Tuesday, May 26, 2015 by Emily

Chemistry
When 1 mole of ethylene (C2H4) is burned at constant pressure, 1410 kJ of energy is released as heat. Calculate (delta) H for a process in which 10.0 of ethylene is burned at constant pressure
Tuesday, May 26, 2015 by Emily

CHEMISTRY
Calculate the pH of a solution contain 0.300 mole per liter of KH2PO4 and 0.0150 mole per liter of K2HPO4.
Tuesday, May 26, 2015 by Ashok

chemistry
If 0.2g of iodine is stirred in 100cm3 of water at 298k till equilibrium is reached what will be the mass of iodine found in solution
Tuesday, May 26, 2015 by saquib

Chemistry
Upon heating 134 g MgSO4 · 7 H2O: (a) how many grams of water can be obtained? (b) how many grams of anhydrous compound can be obtained?
Tuesday, May 26, 2015 by Mark

chemistry
An aluminum pan of mass 100 grams and at a temperature of 375°C is plunged into a vat of water. a. If the pan and the water end up at 45°C, how much energy did the aluminum pan lose? b. Assuming no energy goes into the environment, how much energy must the water have ...
Tuesday, May 26, 2015 by victoria

chemistry
In the lab, an experimenter mixes 9.0 g of water (initially at 23.4°C) with 80 g of a solid metal (initially at 350°C). At thermal equilibrium, he measures a final temp of 55.4°C. What must the specific heat of the metal be?
Tuesday, May 26, 2015 by victoria

chemistry
Calculate the amount of heat needed to convert 45g of ice at –22.0°C to water at 22.0°C.
Tuesday, May 26, 2015 by victoria

chemistry
a mixture of two liquids n2h4 and n2o4 are used in rockets the produce n2 and water vappour
Tuesday, May 26, 2015 by Anonymous

Chemistry
How is a 2.0 M solution of HF different from a 2.0 M solution of acetic acid? Would the two solutions have the same pH level? Why or why not? Please help!
Tuesday, May 26, 2015 by Isabelle

Chemistry
You are given 75mL of 1mol/L NaOH and 75 mL of 1mol/L HNO3 at atmospheric pressure. After mixing the two compounds, he measured a rise in temperature from 25°C to 32°C. Find the change in energy of the system in kJ/mol. (Known: Density of aqueous solution is 1.00g/mL ...
Tuesday, May 26, 2015 by John

Chemistry
What is the molarity of a bleach solution containing 6.6 g of NaOCl per liter of bleach? answer please
Monday, May 25, 2015 by Dave

chemistry
39.3 grams of c6h6 are allowed to react with 108.3 grams of o2. How much co2 will be produced by this reaction?
Monday, May 25, 2015 by Lindsey

Chemistry check my answers
Please check my answers For each of the 7 reactions in this experiment, write a balanced equation and classify it as a synthesis, decomposition, single replacemnt, neutralization, or double replacement reaction. Reaction 1 1)Adjust a burner flae to high heat 2)using crucible ...
Monday, May 25, 2015 by Kim

Chemistry check
H2O2+MnO2 -----> MnO2 + H2O Is my work correct?
Monday, May 25, 2015 by Rain

Chemistry
Using the balanced equation below, how many grams of cesium fluoride would be required to make 73.1 g of cesium xenon heptafluoride? CsF+XeF6 ---> CsXeF7
Monday, May 25, 2015 by Kylar

ap chemistry
a cell is based on the following reaction Fe(s)+2Fe+3(aq) -----> 3Fe+2 (aq) E cell= 1.18 V. Calculate the concentration of iron (II), in M, if the cell emf is 1.28 V. when [Fe^(3+)]= 0.5 M the answer is 0.047 M
Monday, May 25, 2015 by Anonymous

Chemistry
How many milliliters of a 5.0 M H2SO4 stock solution would you need to prepare 111.0 mL of 0.36 M H2SO4?
Monday, May 25, 2015 by Dave

chemistry
how many grams of solid magnesium nitrate should be added to 5.0 grams of solid sodium nitrate in a 500 mL volumetric flask in order to produce an aqueous 0.25M solution of NO3- ions (once the flask is filled to the 500mL volume line)? No idea where to start for this question.
Monday, May 25, 2015 by alex

chemistry
15g of calcium hydroxide is dissolved in 500cm^3 of water 300cm^3 of the solution is used to neutralise hydrocloric acid of/5mol.dm^3 how do i calculate the volume of the acid
Monday, May 25, 2015 by happy

chemistry
How would this problem be worked using dimensional analysis? Answer is 1.32g and I can work it (.900/13.6) * 20 = 1.32 But i need it in dimensional analysis and the hint was to first find volume of mercury. How many grams of alcohol with a density of 0.900 g/cm3 will have the ...
Monday, May 25, 2015 by Rachel

Chemistry
Determine the pH of a buffer made from 250 ml of 0.50M HF and 150 ml of 0.75 M NaF.
Monday, May 25, 2015 by Amber

Chemistry ( I NEED HELP REAL QUICK )
How much Al is needed to react with 675 mL of 0.655M HCl solution according to the reaction => 2Al + 6HCl→2AlCl3+ 3H2 Help your friend!
Monday, May 25, 2015 by Farrell

Chemistry
Methane gas burns in air to give carbon dioxide and water. a) give a chemical equation b) How can the mixture of these gases be separated b) Which gases does it mean?? Can anyone tell me.. Pleease.
Monday, May 25, 2015 by Saurav

chemistry
Why does acetone evapourate faster than water in terms of intermolecular forces
Monday, May 25, 2015 by nicole

chemistry
why does water,oil,acetone and isopropanol have the same concave meniscus shape?
Monday, May 25, 2015 by nicole

Chemistry
A method to determine the chloride ion content of water involves precipitate the chloride ion as silver chloride using silver nitrate. Assuming that all the chloride ions in solution can be precipitated using silver nitrate, explain how this process might be performed and the ...
Sunday, May 24, 2015 by Anonymous

Chemistry
What volume of 1.45 H2SO4 is required to neutralize .050L of .75M KOH?
Sunday, May 24, 2015 by Stephanie

chemistry
A 2.500×10−2M solution of NaCl in water is at 20.0∘C. The sample was created by dissolving a sample of NaCl in water and then bringing the volume up to 1.000 L. It was determined that the volume of water needed to do this was 999.3mL . The density of water at...
Sunday, May 24, 2015 by Jason

chemistry
A 2.500×10−2M solution of NaCl in water is at 20.0∘C. The sample was created by dissolving a sample of NaCl in water and then bringing the volume up to 1.000 L. It was determined that the volume of water needed to do this was 999.3mL . The density of water at...
Sunday, May 24, 2015 by Jason

chemistry
career opportunities available in nursing. 2 companies /organizations in the area that offer jobs in this career??
Sunday, May 24, 2015 by reina bonilla

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