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July 27, 2015

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Methanol is produced commercially by the catalysed reaction of carbon monoxide and hydrogen: CO(g) + 2H2(g)  CH3OH(g). An equilibrium mixture in a 2.00 L vessel is found to contain 0.0406 mol CH3OH, 0.170 mol CO, and 0.302 mol H2 at 500 K. Calculate Kp at this ...
Sunday, June 7, 2015 by Ng Chew Hong

Chemistry
What are some of the distinctive properties of gases with respect to: density, volume, shape?
Sunday, June 7, 2015 by Mark

Chemistry
Calculate the volume of solution of 3.6 M NH4CI needed to prepare 350.0ml of 1.24 M NH4CI. How many grams of ammonium chloride are in the solution you created in the above problem.
Sunday, June 7, 2015 by Donna

Chemistry
How many moles of potassium sulfate would you need to prepare 1200 grams of 5.0% sulfate (m/m) solution? Calculate the volume of solution of 3.6 NH4CI needed to prepare 350.0ml of 1.24 M NH4CI. How many grams of ammonium chloride are in the solution you created in the above ...
Sunday, June 7, 2015 by Donna

Chemistry
A chemist wants to make 150 mL of a 1.26 M solution of carbonic acid to be used in the lab. How many grams of H2CO3 does the chemist need to make this solution? I converted mL to .150L, multiplied .150*1.26= =0.189 to get mol. H2CO3=62.028 so I multiplied this by 0.189 to get ...
Saturday, June 6, 2015 by Nick

Chemistry
Consider a system consisting of 2moles CO2 gas initially at 25 deg and 10 atm and confined to a cylinder of cross section 10.0 square centimeter. lt is allowed to expand adiabatically against an external pressure of 1.0 atm until the piston has moved outwardsthrough 20cm. ...
Saturday, June 6, 2015 by Rudo Kanukamwe

Chemistry
Solid sodium peroxide (Na2O2) reacts with carbon dioxide gas to form solid sodium carbonate and oxygen gas. If I have 56.2 g of Na2O2 and I treat it with 2.4 L of carbon dioxide at 675 Torr and 23.6 „aC, how many grams of sodium carbonate will be produced?
Saturday, June 6, 2015 by Loren

Chemistry
At 2000 ∘C the equilibrium constant for the reaction 2NO(g)←−→N2(g)+O2(g) is Kc=2.4×103. The initial concentration of NO is 0.220M . What is the equilibrium concentration of NO? What is the equilibrium concentration of N2? What is the equilibrium ...
Saturday, June 6, 2015 by Braxten

chemistry
que.1-10 g of a mixture of Bao and Cao require 100ml of 2.5M Hcl to react with it.Find out the amount of Bao in %.
Saturday, June 6, 2015 by parvesh

chemistry
You have a solution which contains an unknown concentration of an organic compound quinone O=CC4H4C=O and an unknown concentration of Pb2+ and Al3+. Explain how to determine the unknown concentrations of quinone, Pb2+ and Al3+.
Saturday, June 6, 2015 by ct

chemistry
10 mL of 0.0100 M HCl are added to 25.0 mL of a buffer solution that is 0.010 M HC2H3O2 and 0.1 M C2H3O2-. What is the pH of the resulting solution?
Friday, June 5, 2015 by Renata

chemistry
Calculate the volume of solution that has a vapour pressure of 25.8 mbar and contains 200.3 g of galactose, C6H12O6, at a temperature of 22.0 °C. The vapour pressure of pure water at 22 °C is 26.40 mbar, the density of water is 1.00 g mL-1, and assume no change in ...
Friday, June 5, 2015 by Jane Smith

Chemistry
energy required for ionisation of 0.02 gram atom of magnesium is x Kj .the amount of energy required to ionise 1 atom of magnesium is
Friday, June 5, 2015 by sam

Chemistry
How much heat is required for 32.5g of Na2co3 to completely decompose?
Thursday, June 4, 2015 by Jan

Chemistry
what volume of 0.200M KOH is needed to neutralize 32.7 grams of h3po4, which has been dissolved in 250 ml water?
Thursday, June 4, 2015 by Nick

Chemistry
A solution of methanol and water has a vapour pressure of 213 Torr. What would you predict as the mole fractions of each component, assuming ideal behaviour? The vapour pressures of methanol and water are 256 Torr and 55.3 Torr, respectively
Thursday, June 4, 2015 by Matt

Chemistry
How many grams of zinc metal are required to produce 2.00 L of hydrogen gas at STP according to the chemical equation shown below? Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
Thursday, June 4, 2015 by Ryan

Chemistry Please Help Thanks!
Calculate the volume of solution that has a vapour pressure of 25.8 mbar and contains 200.3 g of galactose, C6H12O6, at a temperature of 22.0 °C. The vapour pressure of pure water at 22 °C is 26.40 mbar, the density of water is 1.00 g mL-1, and assume no change in ...
Thursday, June 4, 2015 by Ben

Chemistry
How many moles are in 1.59 kg of sodium?
Thursday, June 4, 2015 by Ava

Chemistry
Did Dalton and Thomson believe that the atom was made of solid mass?
Thursday, June 4, 2015 by Hannah

CHEMISTRY
Ignoring activities, determine the molar solubility (S) of Zn(CN)2 in a solution with a pH = 1.94. Ksp (Zn(CN)2) = 3.0 × 10-16; Ka (HCN) = 6.2 × 10-10.
Wednesday, June 3, 2015 by Anonymous

CHEMISTRY
Determine the molar solubility (S) of Ag2CO3 in a buffered solution with a pH of 3.378 using the systematic treatment of equilibrium. Ksp(Ag2CO3) = 8.46 × 10–12; Ka1(H2CO3) = 4.45 × 10–7; Ka2(H2CO3) = 4.69 × 10–11.
Wednesday, June 3, 2015 by Anonymous

Chemistry
You have 30mL of .2M HF being titrated with .15M KOH. The pka is 3.17....half way to the equivalence point you have 20mL of KOH. Find the pH when you add 40mL of KOH . Find the pH when you have 100mL of KOH added. Sol:pH = pKa + log (base / acid) = -log 3.17 + log ( .009/ .006)
Wednesday, June 3, 2015 by Nisar

Chemistry
Will 1 L of 1 M NaCl contain more chloride ions than 0.5 L of 1 M MgCl2 explain. One liter of 1 M NaCl contains________ mole(s) of NaCl, therefore_______ mole(s) of chloride ions. 0.5 L of 1 M MgCl2 contains__________ mole(s) of MgCl2, therefore_________ mole(s) of chloride ions.
Wednesday, June 3, 2015 by Mark

Chemistry
(a) How many grams of KNO3 are needed to make 430 mL of a solution that is to contain 2.9 mg/mL of potassium ion?
Wednesday, June 3, 2015 by Mark

Chemistry
Describe briefly,but including all essential experimental details and relevant equations, how you would prepare pure dry samples of - anhydrous iron (ll)chloride starting from iron.
Tuesday, June 2, 2015 by Violet

Chemistry
how many grams of butane must be burned in an excess of o2 gas in order to produce 7.64l of co2?
Tuesday, June 2, 2015 by Arielle

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

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