Tuesday
August 23, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
An interference filter is to be constructed for isolation of the nitrobenzene absorption band at 1537 cm-1. (a) If it is to be based on first-order interference, what should be the thickness of the dielectric layer (refractive index of 1.34)? (b) What other wavelengths would ...
Saturday, February 27, 2016 by Aaron

Chemistry
Calculate the volume of hydrogen produced at s.t.p when 25g of zinc are added to excess dilute hydrochloric at 3degree and 778mmhg pressure
Saturday, February 27, 2016 by Jubilee

Chemistry
If 10.0 L of hydrogen collected over water at 20' C and 750 mm Hg are produced, how many grams of iron metal must react with excess steam?
Saturday, February 27, 2016 by Yoni

Chemistry
Hi! I'm having trouble solving this question, not sure how to go about starting it: Magnalium is a solid mixture of aluminum metal & magnesium metal. An irregular shaped chunk of a sample of magnalium is weighed twice, once in air (211.5g) and once in vegetable oil (135.3g...
Friday, February 26, 2016 by Mila

chemistry
The formula for rust can be represented by Fe2O3. How many moles of Fe are present in 27.6 g of the compound?
Friday, February 26, 2016 by jessie

Chemistry
An interference filter is to be constructed for isolation of the nitrobenzene absorption band at 1537 cm-1. (a) If it is to be based on first-order interference, what should be the thickness of the dielectric layer (refractive index of 1.34)? (b) What other wavelengths would ...
Friday, February 26, 2016 by Joseph

Chemistry
For the gratings (84.0 lines per millimeter and 15.0 mm of illuminated area) calculate the wavelengths on the first and second-order diffraction spectra at reflective angles of (a) 20 degrees and (b) 0 degrees. Assume the angle of incidence is 45 degrees.
Friday, February 26, 2016 by Joseph

Chemistry
what is the oxidation number of Chlorine in KCIO4???
Friday, February 26, 2016 by kevin

Chemistry
27% of heat produced by the stove's gas burner is transferred to the soup in the covered pot, the rest is lost. Determine the total mass in grams of methane that must be burned to heat 800 ml of water from 22 to 90 degrees C. The density is 1.08 g/ml and the specific heat ...
Friday, February 26, 2016 by Dan

Chemistry
What will be the volume of ammonia formed from 2L of nitrogen and 2L of hydrogen
Friday, February 26, 2016 by Mohammed

chemistry
I need help. I have no clue how to find this. A flask is charged with 1.680 atm of N2O4(g) and 1.220 atm of NO2(g) at 25 degrees celcius. The equilibrium reaction is N2O4 <-> 2 NO2 After equilibrium is reached, the partial pressure of NO2 is 0.550 (a) What is the ...
Friday, February 26, 2016 by Alexus

Chemistry
Calculate the entropy change accompanying conversion of 1 mole of ice at 273 K and 1 atm pressure into steam at 373 K and 1 atm pressure, given that at 273 K, the molar heat of fusion of ice is 6 kJ/mol and at 373 K, the molar heat of vapourization of water is 40.60 kJ/mol. ...
Friday, February 26, 2016 by Mahesh

chemistry
Imagine that you have a 5.50 L gas tank and a 3.50 L gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 155 atm , to what pressure should you fill ...
Friday, February 26, 2016 by lily

Chemistry
Calculate the mass in grams present in 0.95 mole of sodium hydrogen trioxocarbonate(iv)
Thursday, February 25, 2016 by Hukay baso

Chemistry
If a metal ore contains 22.5% pure metal, how many pounds of pure metal can be obtained from 79 pounds of metal ore? Answer in units of pounds.
Thursday, February 25, 2016 by Hector

Chemistry
A chemist needs a 50% of sulfuric acid. She mix 2 liters of 20% of sulfuric acid with a sample of 60% of sulfuric acid. Write a equatoin that models the situation and use it to find how much the 50% of the sulfuric acid she needs to use?
Thursday, February 25, 2016 by James

Chemistry
The balanced reaction equation for the combustion of heptane, C7H16, is given below. If the reaction produced 37.5 g CO2, how many grams of heptane were burned?
Thursday, February 25, 2016 by Veronique

Chemistry
Consider the following reaction: CO2 (g) + H2 (g) CO (g) + H2O (g) Calculate the value of the equilibrium constant, Kc, for the above system, if 0.1908 moles of CO2, 0.0908 moles of H2, 0.0092 moles of CO, and 0.0092 moles of H2O vapour were present in a 2.00 L reaction vessel...
Thursday, February 25, 2016 by kevin

Chemistry
2. Does a precipitate of silver chloride form when 200.0 mL of 1.0 x 10-4 M AgNO3 (aq) and 900.0 mL of 1.0 x 10-6 M KCl (aq) are mixed at 25oC?[ Ksp AgCl @ 25oC = 1.6 x 10-10]
Thursday, February 25, 2016 by kevin

Chemistry-nudge the
A 4.30 g nugget of pure gold absorbed 298 J of heat. The initial temperature was 22.0°C. What was the final temperature? °C
Thursday, February 25, 2016 by Karla

Chemistry
A 4.30 g nugget of pure gold absorbed 298 J of heat. The initial temperature was 22.0°C. What was the final temperature? °C
Thursday, February 25, 2016 by Karla

Chemistry
Why is methanol a good solvent to recrystallize biphenyl?
Thursday, February 25, 2016 by Danny

Chemistry
Calculate how many grams of FeSO4.7 H2O (MW = 278.02 g/mol) will be needed to prepare 1 mL of a 0.2 M FeSO4 solution? Is that .0304g?
Thursday, February 25, 2016 by Feufolia

Chemistry
What functional group(s) does 4-Ethylphenol have? I know it has an alcohol. Should I also say that it has an arene?
Thursday, February 25, 2016 by Anonymous

Chemistry
Calculate how many grams of FeSO4 . 7 H2O (MW = 278.02 g/mol) will be needed to prepare 1 mL of a 0.2 M FeSO4 solution? Am I right when I say we'd need
Thursday, February 25, 2016 by Feufolia

Chemistry 101
If gold sells today for 1625 per ounce, and a large mining truck hauls 400 tons of gold ore, what is the value of the gold in each truck if each ton of gold ore contains 1.0 ounces of gold? Use dimensional analysis.
Thursday, February 25, 2016 by Lilly

Chemistry 101
If gold sells today for 1625 per ounce, and a large mining truck hauls 400 tons of gold ore, what is the value of the gold in each truck if each ton of gold ore contains 1.0 ounces of gold? Use dimensional analysis.
Thursday, February 25, 2016 by Lilly

Chemistry
If 0.30 mol N2H4 is reacted with 0.50 mol N2O4, how many moles of N2 can be formed?
Thursday, February 25, 2016 by Christian

chemistry
Write the chemical equation that oxidize oxalic acid to carbon dioxide and water
Thursday, February 25, 2016 by james

COLLEGE,CHEMISTRY
CH3-C-CH3=CH2+H-OH-->
Thursday, February 25, 2016 by RINTU

Chemistry
Why are liquids that are refrigerated and stored in glass always colder than those refrigerated and stored in plastic or cardboard?
Thursday, February 25, 2016 by Ali

Chemistry
How does salt hydrolysis work between sodium hydroxide and lactic acid in a titration?
Thursday, February 25, 2016 by Hannah

chemistry
___Fe(NO3)2 + Al___Al(NO) +__Fe
Wednesday, February 24, 2016 by Sabrina

Chemistry
Find the mass of urea (CH4N2O) needed to prepare 50.9 g of a solution in water in which the mole fraction of urea is 7.69×10−2.
Wednesday, February 24, 2016 by Nicole

Chemistry
a solution is prepared by dissolving 15.0 grams of ni(no3)2 in enough water to make 250 ml of solution what is the molarity of this solution
Wednesday, February 24, 2016 by Madison

Chemistry
C+H2O ARROW CO+H2
Wednesday, February 24, 2016 by C+H2O ARROW CO+H2

Chemistry
how does one go about finding the Tf of this equation 100Hf+100cw(Tf-0) + 300w(Tf-25) =0 and can you also explain what cw and Hf mean? i have no idea.
Wednesday, February 24, 2016 by Student

Chemistry
I have to write the rate law for two elementary reaction equations A ) 2a+b>c+d B ) X+Y>Z I'm pretty sure it's just k[ A ][ B ] and k[ X ][ Y ] but does the coefficient affect it in this case? is it [ A ]^2 ?
Wednesday, February 24, 2016 by Dan

Chemistry
PART 1 >>Trial 1 Reactant Solution A 10 ml I^-, 5.0 ml S2O3^2- Reactant Solution B 10 ml S2O8^2-, 1 ml starch time to react = 10 seconds >>Trial 2 Reactant Solution A 10 ml I^-, 5.0 ml S2O3^2- Reactant Solution B 5 ml S2O8^2-, 1 ml starch time to react = 20 seconds...
Wednesday, February 24, 2016 by Dan

Chemistry
Suppose that 100.0 g of ice a 0 degreesC are added to 300.0 g of water at 25.0 degrees . Is this sufficient ice to lower the temperature of water to 5.00 degrees C and still have ice remaining? Calculate the energy (heat) which must be removed from water to achieve the desired...
Wednesday, February 24, 2016 by Sage

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 Tf= 109 C? Is it in the steam phase?
Wednesday, February 24, 2016 by Student

Chemistry
if 9560 J of energy were absorbed by 25.0g of ice at 0 degrees Celsius what would be the final temperature? First you must calculate the energy required to melt ice completely. With the remaining energy (Q). This is the equation i came up with but i'm not even sure if its ...
Wednesday, February 24, 2016 by Sage

Chemistry
PART 1 >>Trial 1 Reactant Solution A 10 ml I^-, 5.0 ml S2O3^2- Reactant Solution B 10 ml S2O8^2-, 1 ml starch time to react = 10 seconds >>Trial 2 Reactant Solution A 10 ml I^-, 5.0 ml S2O3^2- Reactant Solution B 5 ml S2O8^2-, 1 ml starch time to react = 20 seconds...
Wednesday, February 24, 2016 by Dan

Chemistry
I have to write the rate law for two elementary reaction equations A ) 2a+b>c+d B ) X+Y>Z I'm pretty sure it's just k[ A ][ B ] and k[ X ][ Y ] but does the coefficient affect it in this case? is it [ A ]^2 ?
Wednesday, February 24, 2016 by Dan

chemistry
Identify d solid remaining wen each of d following is Heated (a)lithium trioxonitrate(b)potassium trioxonitrate(c)calcium trioxonitrate
Wednesday, February 24, 2016 by Augustine

chemistry
how many chloride ions are in o.35 mol MgCl2?
Wednesday, February 24, 2016 by Anonymous

AP Chemistry
If 400 mL of 3.5 molar HCl solution is added to 200 mL of 2.3 molar NaOH solution, what will be the molarity of NaCl in the resulting solution? Answer in units of M.
Wednesday, February 24, 2016 by Zach

Chemistry
The two most common oxidation states are Cr(III) and Cr(VI). Balance the following oxidation-reduction equations that involve one of these oxidation states of chromium. Assume that the reactions occur in acidic solution. A. Cr(s) + O2 (g) + H^+ <-> Cr^3+ B. Fe^2+ (aq) + ...
Wednesday, February 24, 2016 by Anonymous

Chemistry lab
1)Why is it necessary to heat the alum until its mass does not change by more than 2mg? 2)Why its it necessary to store the alum in a disccator while it cools before measuring the mass? ( systhesis and analysis of alum crystals experiment)
Tuesday, February 23, 2016 by Paul

Chemistry (balancing equations)
Balanced Equation: 2 CuNo3 + MgCl2 ---> 2 CuCl + MgNO3 Is this correct?
Tuesday, February 23, 2016 by M

Chemistry
If I have 275 mL of a 1.5 M NaBr solution, what will the concentration be if I add 450 mL more water to it?
Tuesday, February 23, 2016 by Anonymous

chemistry
if you mixed 100 grams of Magnesium nitrite with 100 grams of Lithium Phosphide and made magnesium phosphide and lithium nitrite how many grams of each product would you make and how many grams of each reactant would be left over at the end?
Tuesday, February 23, 2016 by Anonymous

chemistry
If you mixed 100 grams of magnesium nitrite with 100 grams of lithium phosphide and made magnesium phosphide and lithium nitrite how many grams of each product would you make and how many grams of each reactant would be left over at the end.
Tuesday, February 23, 2016 by anonymous

CHEMISTRY! HELP
I'm not sure how to do or show the work for these two questions. A) & B.)!! please anyone help: A.) Suppose a chemical reaction starts with 5.00 g of copper (i) nitrate and 2.00 g of magnesium chloride. Balanced Equation: 2 CuNo3 + MgCl2 ---> 2 CuCl + MgNO3 1.) ...
Tuesday, February 23, 2016 by Maddie

Chemistry
What functional group(s) is(are) in 4-hydroxoybenzoic acid? My Answer: Would it be carboxylic acid and an ester?
Tuesday, February 23, 2016 by Anonymous

Chemistry
Are these isotonic hypertonic or hypotonic. 1.5% w/v NaCl 5.0% w/v glucose 0.55%w/v NaCl And why??
Tuesday, February 23, 2016 by Angel

Chemistry
Pyridine, a substance used as a catalyst in some synthetic reactions is a very weak base its degree of ionization is equal to 0.03% in solution 0.02 mol L -¹. Determine the ionization constant.
Tuesday, February 23, 2016 by Michael

Chemistry
A 25.00 mL sample of sulfuric acid is titrated with 6.02 x 10^2 M barium hydroxide. The equivalence point is reached at 21.68 mL of barium hydroxide solution. what is the molarity of the sulfuric acid solution?
Tuesday, February 23, 2016 by jess

Chemistry
a 30 mL sample of vinegar is titrated with .1098 M NaOH. it takes 43.28 mL naOH solution to reach the endpoint. Determine the acetic acid concentration in the vinegar solution?
Tuesday, February 23, 2016 by Jeff S.

Chemistry
Assuming an efficiency of 46.80%, calculate the actual yield of magnesium nitrate formed from 147.9g of magnesium and excess copper(II) nitrate. Mg + Cu(NO3)2 --> Mg(NO3)2 + Cu I can't figure out how to even set this up much less solve it...
Tuesday, February 23, 2016 by Alexis

General chemistry i
Is this a redox reaction? 4Cr+3O2 -> 2Cr2O3
Tuesday, February 23, 2016 by Dean A

Chemistry
No change of mass was observed when a definite amount of a mixture of KI and NaCl is converted to sulphate salts. What is the percentage composition of the mixture?
Tuesday, February 23, 2016 by Anamika

Chemistry
What is the reaction of dilute HCl with Zn?
Tuesday, February 23, 2016 by Anamika

Chemistry
Are any of these molecules aromatic? If so, why? 1. C5PH5 2. [C4N2H5]- 3. [C4B2H]2- 4. [P5]- 5. [C7H7]+ 6. [C4NH5]- 7. [C8H8]2-
Tuesday, February 23, 2016 by Cole

Chemistry
A 1.1% (w/w) solution of cocaine hydrochloride (molar mass 339.81 g/mol) in water. Calculate the molal concentration. Is it 0.0297 mol/kg?
Monday, February 22, 2016 by Student

CHEMISTRY
I'm showing the procedure of the lab and what was asked. What I have question on is towards the end. Much help would be appreciated a lot!! First I had to balance the equation given to me: 2 Na HCO3 (s) Δ over arrow (produces) Na2 CO3 (s) + CO2 (g) + H2O (g). From the...
Monday, February 22, 2016 by Allie

CHEMISTRY
I'm showing the procedure of the lab and what was asked. What I have question on is towards the end. Much help would be appreciated a lot!! First I had to balance the equation given to me: 2 Na HCO3 (s) Δ over arrow (produces) Na2 CO3 (s) + CO2 (g) + H2O (g). From the...
Monday, February 22, 2016 by Allie

Chemistry
Imagine that you have a pure sample of an unknown compound that you are told is either 2-naphthol OR benzoic acid. In the lab, you also have access to samples of pure 2- naphthol and pure benzoic acid. However, both of these pure substances melt at 123 °C: the same ...
Monday, February 22, 2016 by Anonymous

Chemistry
When aluminum is reached in a closed container with 8.36 g of O2, how many grams of Aluminum oxide can form
Monday, February 22, 2016 by Audrey

Chemistry
Suppose you have 5.00g of powdered magnesium metal, 1.00L of 2.00M potassium nitrate solution, and 1.00L of a 2.00M silver nitrate solution. a) Which one of the solutions will react with the magnesium powder? I don't understand how to go about answering this question at ...
Monday, February 22, 2016 by Feufolia

Chemistry
Calculate the maximum wavelength of light capable of removing an electron for a hydrogen atom from the energy state of n=4 if it requires an energy of at least 1.36 x10^-19 J to do this. I just want to know how to find the second n value so i can solve with rydeburgs equation??
Monday, February 22, 2016 by Maxx

Chemistry
The methane gas is formed by 25% hydrogen in mass which the ratio between the mass of carbon and hydrogen in this gas?
Monday, February 22, 2016 by Michael

chemistry
a.identity the phases that exist in a copper pan containing two iron nails ,a litre of water and four glass marbles b.A beaker contains clear, colourless liquid.How would you determine whether it contained dissolved table salt without tasting it? c. suggest a separation method...
Monday, February 22, 2016 by snothile

Chemistry
Calculate the maximum wavelength of light capable of removing an electron for a hydrogen atom from the energy state of n=4 if it requires an energy of at least 1.36 x10^-19 J to do this. Please help with formulas to use?
Monday, February 22, 2016 by Maxx

Chemistry
the longest wavelength of light that will cause an electron to be emitted from a metal is 520nm. what is the work function for this metal? (note: the work function is given as kJ/mole of electrons released)
Monday, February 22, 2016 by Jen

chemistry
If you begin with 0.030 L of a 2.5M NaOH solution, what concentration will you end up with if you dilute it to 0.050?
Monday, February 22, 2016 by Anonymous

chemistry
What volume of oxygen is required to completely combust 80 of butane
Monday, February 22, 2016 by perpetual

CHEMISTRY
find the concentrations of H+, HCO3-, CO3 2- in a 0.025M in H2CO3 solutions
Monday, February 22, 2016 by ADAM

CHEMISTRY
WHICH OF THE FOLLOWING IS TRUE FOR AN ACID? A. IT PRODUCES EFFERVESCENCE WITH BAKING POWDER. B. IT TURNS UNIVERSAL INDICATOR BLUE. Answer This Quest
Monday, February 22, 2016 by vidya

Chemistry
A compound has the empirical formula CHCL .A flask with volume 253 cm3 at temperature of 373K and pressure of 1.0 atm contains 0.8 g of the gaseous compound. Find the molecular formula of the compound.
Monday, February 22, 2016 by Amy

Chemistry
Why do warm temperatures speed up the fermentation of milk?
Monday, February 22, 2016 by Ali

Chemistry
2g AgCl is obtainded by adding an excess of AgNO3 solution to a solution containing 1g of a mixture of NaCl and KCl.What is the ratio of moles of two salts in the mixture?
Monday, February 22, 2016 by Anamika

Chemistry
The world record for a human holding their breath is 11 minutes, but most people can only hold it for a few minutes. If a women holds her breath at the maximum lung capacity (4.2 L), calculate the final pressure in her lungs, if her body temperature is 37.0 C and the ambient ...
Sunday, February 21, 2016 by Boberto

Chemistry
Calculate the following and write your answer in scientific notation 6.6 x 10^6 (8.8 x10^2) x (2.5 x 10^3)
Sunday, February 21, 2016 by Anonymous

Chemistry
How many grams of NaNO2 must be added to 1 liter of 1.00 M HNO2 solution in order to prepare a buffer solution with pH = 4.14? pH = 3.14? My work: ka = pH(buffer ratio) 4.5 * 10^-4 = 1.000*10^-4.14 (x M of base/1.00 M of acid) x = 6.21 6.21 M = (6.21 moles/1 L)(1 L) = 6.21 ...
Sunday, February 21, 2016 by Maddy

Chemistry
At what pressure would 0.150 mole of nitrogen gas at -23.0oC occupy 8.90 L? -23.o0c = 250 K P=(0.150 mol)(8.31 KPA x L/ K x mol)(250 K) = P is this right?
Sunday, February 21, 2016 by Boberto

Chemistry - Vapor Pressure
a.)What is the partial vapor pressure of a benzene above solution obtained by mixing 44.7 g benzene, C6H6, and 77.3 g toluene, C6H5CH3, at 25 ∘C? At 25 ∘C the vapor pressure of C6H6 = 95.1 mmHg; the vapor pressure of C6H5CH3 = 28.4 mmHg. b.)What is the partial ...
Sunday, February 21, 2016 by Anonymous

Chemistry
For the reaction between ammonia and hydrochloric acid to produce ammonium chloride; What volume of ammonia is used (at 20 Celsius and 760mmHg) if 12.5gmof ammonium chloride are produced in the reaction? How many molecules of ammonia does this represent?
Sunday, February 21, 2016 by Sam

chemistry
is it other than CH3COOH + C2H5OH => CH3COOC2H5 propanoic acid and isoamyl alcohol to make isoamyl propanoate?
Sunday, February 21, 2016 by ss

organic chemistry
is it anything other to form isopentyl propionate
Sunday, February 21, 2016 by ss

Chemistry
If the density of a gas is 1.2g/L at 745.torr and 20 Celsius, what is the molecular mass?
Sunday, February 21, 2016 by Sam

Chemistry
What is the density of NH3 at 800torr and 25 Celsius?
Sunday, February 21, 2016 by Sam

chemistry functional groups
Can a singly bonded CH2 group be classified as an alkyl or an alkane group? It's not the vinyl. Thanks!
Sunday, February 21, 2016 by Anonymous

chemistry
which alcohol and carboxylic acid would produce isoamyl propanoate by Fischer esterification
Sunday, February 21, 2016 by mm

Chemistry
When 6.0L of H2 reacts with 2.0L of N2, 4.0L of gaseous product are formed. All volumes of gases are measured at the same temperature and pressure. What is the formula of the product? Hint: Assume all reactants are consumed.
Sunday, February 21, 2016 by Cat

Chemistry
FB1 is a solution containing a mixture of potassium carbonate and sodium hydrogen carbonate . 25cm^3 of this mixture was to titrated against 0.250mol/dm^3 solution of HCL. In one titration using phenolphthalein as indicator, 10.00cm^3 of the acid was needed. In another ...
Sunday, February 21, 2016 by Diane

chemistry
WHICH OF THE FOLLOWING IS TRUE FOR AN ACID? A. IT PRODUCES EFFERVESCENCE WITH BAKING SODA B. IT TURNS UNIVERSAL INDICATOR BLUE.
Sunday, February 21, 2016 by vidya

Chemistry
Gasoline, which can be represented by the formula octane, bulk density is 704 g/l. To estimate the variation in enthalpy when burning 28.5 liters gasoline, based on the binding energies: 0 = 0 (117 kcal); C = 0 (173 kcal); 0 h (111 kcal); C-C (83 kcal); C-H (99 kcal)
Sunday, February 21, 2016 by Nayara

Chemistry
A 10.3g sample of an elemental gas has a volume of 58.4L at 758torr when the temperature is 2.5 C. Determine the identity of the gas.
Sunday, February 21, 2016 by Sam

Chemistry
Gasoline, which can be represented by the formula octane, bulk density is 704 g/l. To estimate the variation in enthalpy when burning 28.5 liters gasoline, based on the binding energies: 0 = 0 (117 kcal); C = 0 (173 kcal); 0 h (111 kcal); C-C (83 kcal); C-H (99 kcal)
Saturday, February 20, 2016 by Anonymous

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