Monday
September 26, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
How many atoms of carbon are needed to produce 0.45 mol Al? 3C + 2Al2O3 4Al + 3CO2 A. 2.6 × 1026 atoms B. 9.7 × 1024 atoms C. 3.0 × 1022 atoms D. 2.0 × 1023 atoms
Friday, August 19, 2016 by emma

Chemistry
What is the oxidation state of Cr in K2Cr2O4?
Friday, August 19, 2016 by anon

Chemistry
Aqueous sulfurous acid H2SO3 and aqueous sodium chloride are formed by the reaction of aqueous sodium sulfite Na2SO3 and aqueous hydrochloric acid HCl . Write a balanced chemical equation for this reaction.
Friday, August 19, 2016 by R

chemistry help?!
Which properties result from minimal interactions between molecules in a gas? A. A characteristic geometric shape and limited particle motion B. A random shape, limited particle motion, and inability to be compressed C. A random shape, significant particle motion, and ability ...
Friday, August 19, 2016 by Jessie

chemistry help
How do forces determine the shape of a protein? A. The covalent bonds in the protein determine the shape of the protein. B. The protein folds into complex shapes through intermolecular forces. C. Polar parts of a protein are repelled by water. D. Hydrophobic parts of a protein...
Friday, August 19, 2016 by Jessie

chemistry help?!
Which statement correctly pairs the order of a reaction with the units for the rate constant? A. third order; s/M B. zero order; 1/(M2) C. second order; 1/(M•s) D. first order; 1/M
Friday, August 19, 2016 by Jessie

chemistry help?!
Which of the following terms are present in the rate law? A. The rate constant, the concentration of the reactants, and the order of the reactants B. The rate constant and the concentration of the reactants C. The rate constant and the temperature of the reactants D. The rate ...
Friday, August 19, 2016 by Jessie

chemistry
Which of the following terms are present in the rate law? A. The rate constant, the concentration of the reactants, and the order of the reactants B. The rate constant and the concentration of the reactants C. The rate constant and the temperature of the reactants D. The rate ...
Thursday, August 18, 2016 by Jessie

Chemistry
Which of the following is NOT a characteristic of a strong acid and a strong base? A. Has a [H+] higher than water B. Is corrosive to most metals C. Has a pH at the extreme end of the scale D. Completely dissociates in water
Thursday, August 18, 2016 by Cherry

Science - Chemistry
If the rate law of a chemical reaction is k[NH4+]2[NO2–], what is the order of the reaction? 1. The order of the reaction cannot be determined. 2. 3 3. 1 4. 2
Thursday, August 18, 2016 by Jessie

AP Chemistry help!!!!!
How does the boiling point of ethane (CH3CH3) compare with that of ethanol (CH3CH2OH)? 1. The boiling point of ethane is higher because it has stronger London dispersion forces. 2. The boiling point of ethane is higher because it has stronger dipole-dipole forces. 3. The ...
Thursday, August 18, 2016 by Stephen

Chemistry
Chlorine has two isotopes with mass number 35 and 37. Calculate the relative abundance of the two isotopes accounting for normal atomic mass of 35.5
Thursday, August 18, 2016 by Iyana

chemistry
calculate no of neutrons present in 1*210^25 atoms of oxygen(atomic no of oxygen=8,mass no of oxygen=17
Wednesday, August 17, 2016 by ria

chemistry
2.00g of carbonate reacts with excess hydrobromic acid. Use this balanced equation to fond the theoretical yield. Na2Co3 + 2HBr = CO2 + H2O + 2NaBr
Tuesday, August 16, 2016 by jane

chemistry
A flask contains 0.260 mol of liquid bromine, Br2. Determine the number of bromine molecules present in the flask. Express your answer numerically in molecules.
Tuesday, August 16, 2016 by diana

Chemistry
How do you calculate alkalinity in chemistry? Ex: List the values for total alkalinity for Sample A and Sample B A 104 drops of titrant (5.25mL) 3 drops of C20 H14 O4 B 81 drops of titrant (4.25mL) 3 drops od C20 H14 O4
Monday, August 15, 2016 by anon

Chemistry
Write the net ionic equation for HClO4(aq) + NaOH(aq) --> H2O (l) + NaClO4(aq).
Monday, August 15, 2016 by Heidy

Chemistry
Calculate how many grams of the substance and how many grams of water is in a solution of 400g with a concentration of a 30%
Monday, August 15, 2016 by David

chemistry
25 ml of SHW containing CaCO3 1 g/L consumes 12 ml of EDTA. 25 ml of hard water consumes 8 ml of standard EDTA solution. After boiling the sample, 25 ml of the boiled hard water consumes 6 ml of standard EDTA solution. Calculate the total, permanent and temporary hardness
Monday, August 15, 2016 by priyanka

Chemistry
a 0.1 gm sample requires 20.5 ml B for reaction. the B was standardized by titrating 25 ml of a 0.1M CaCl2 solution, requiring 30 ml B. calculate the percent Al2O3
Monday, August 15, 2016 by 7aji

Chemistry
Determine the cell potential from the following half cells: Pb^o/Pb2+ and ZN^O/Zn2+ whre [Pb2+]=.86Mand [Zn2+]=0.35M Calculate K for this reaction. How long in hours would you have to let it go until you lower the voltage to 95 percent of the E from the Nernst equation at 7.2?
Sunday, August 14, 2016 by Jessica

Chemistry
How many grams of hydrogen chloride acid containing 10% by mass of hydrogen chloride acid would be required to dissolve 13g of zinc
Sunday, August 14, 2016 by Mike

Chemistry
What are the equilibrium concentrations of all the solute species in a 0.95 M solution of hydrogen cyanide, HCN? The Ka value = 6.2 x 10^-10. (a) [H3O+], M; (b) [OH-], M; (c) [HCN], M; (d) What is the pH of the solution? For HCN So far i have calculated the concentration of ...
Sunday, August 14, 2016 by Alice

Chemistry
What volume of 0.123M NaOH contains 0.025 moles of NaOH?
Saturday, August 13, 2016 by Alicia

Chemistry
Calculate the mass of the precipitate formed when 2.27 L of 0.0820 M Ba(OH)2 are mixed with 3.06 L of 0.0664 M Na2SO4.
Saturday, August 13, 2016 by David

Chemistry
Calculate the mass of solid which would be precipitated when 35g of carbon 4 oxide are passed through a solution of calcium hydroxide Show your work
Saturday, August 13, 2016 by Mike

chemistry
?Fe(2+)+?NO3(-)+H(+)==》No+Fe(3+)+​H2O What's the balanced equation?
Saturday, August 13, 2016 by Fred

Analytical Chemistry
how much volume of h2so4 is needed to produce a 0.953 Normality) of h2so4 if the 1 liter solution is 1.14 g/mL in density?
Saturday, August 13, 2016 by Sham

Chemistry
What is the number of molecules in 22. 4 dm^3 of nitrogen gas at STP?
Friday, August 12, 2016 by Vinayak

science(chemistry)
A laboratory instructure gives a sample of Amino-powder to each if four students,1,2,3 and 4,and they weigh the samples.The true value is 8.72g.Their results for three trails are (1),8.72g,8.74g,8.70g (2),8.56g,8.77g,8.83g (3),8.50g,8.48g,8.51g (4),8.41g,8.72g,8.55g (A)...
Friday, August 12, 2016 by mary tembo

Chemistry
How many mL of 0.1 N NaOH are required to react with 100 mEq of H2SO4?
Thursday, August 11, 2016 by David

chemistry
Predict the heat output of the combustion of 1L of octane at 298K. It's mass density is.703 g/cm3
Thursday, August 11, 2016 by deepsikha

Chemistry
The density of silver is 10.5 g/mL, so what is the mass of a 16.3cm^3 piece of silver?
Wednesday, August 10, 2016 by Domo

Chemistry
We add 54g of aluminum to a graduated cylinder containing 50mL of water. What will be the level of water in the cylinder after aluminum has been added?
Wednesday, August 10, 2016 by Domo

Physical Chemistry
A 1.00M sucrose solution freezes at -1.8 degree Celsius. What is the freezing point of 1.00M glucose solution?
Wednesday, August 10, 2016 by Winnie

Chemistry
The weight of a pure sample of KClO3 to be decomposed in order to get 0.96 of O2.
Wednesday, August 10, 2016 by Yathishnv27

chemistry
how many numbers of oxygen molecules are present in 3 litres of CO2 at STP?
Wednesday, August 10, 2016 by sony

chemistry
when heated, kclo3 decomposes into kcl ad 02. 2kclo3--> 2kcl+3o2 if this reaction produced 61.7 g of kcl, how much o2 was produced (in grams)?
Wednesday, August 10, 2016 by AA

ap chemistry
Propane gas and oxygen gas will chemically react via combustion. Write a blanced equation for this change and then use stoichiomety problem solving to determine the number of carbon dioxide molecules that can theoretically form.
Wednesday, August 10, 2016 by anonymous

ap chemistry
Ammonia decompose upon intense heating to produce nitrogen and hydrogen elemental products. Write a balanced equation and then use stoichiometry problem solving to determin the mass of nitrogen product that can form if exactly 25.50g of ammonia is fully decomposed.
Wednesday, August 10, 2016 by anonymous

chemistry
Ammonia decomposes upon heating to produce nitrogen and hydrogen elemental products. Write a balanced equation and then use stoichiometry problem solving to determin the mass of nitrogen product that can form if exactly 25.50 grams of ammonia(NH3) is fully decomposed.
Wednesday, August 10, 2016 by anonymous

chemistry
A major component of gasoline is octane C8H18. When octane is burned in air, it chemically reacts with oxygen gas O2 to produce carbon dioxide CO2 and water H2O. What mass of octane is consumed by the reaction of 8.8g of oxygen gas? Round your answer to 2 significant digits.
Tuesday, August 9, 2016 by Emily

ap chemistry
use dimensional analysis to find how many moles of nitrate ions are in 40.0 mL of a 0.75 M aqueous solution of aluminum nitrate
Tuesday, August 9, 2016 by anonymous

Chemistry
Define normality
Tuesday, August 9, 2016 by Joule eve

Chemistry
If 0.500 mol of each of the following solutes is dissolved in 2.0 L of water, which will cause the greatest increase in the boiling point of the solution? A. KI B. CO2 C. Na2SO4 D. NaCl
Monday, August 8, 2016 by OTP

Chemistry
If 0.500 mol of each of the following solutes is dissolved in 2.0 L of water, which will cause the greatest increase in the boiling point of the solution? A. KI B. CO2 C. Na2SO4 D. NaCl
Monday, August 8, 2016 by SahDuuude

Chemistry
If 152 grams of ethane (C2H6) are reacted with 231 grams of oxygen gas, what is the excess reactant? 2C2H6 + 7O2(g) → 4CO2(g) + 6H2O(g)
Monday, August 8, 2016 by Rohit

chemistry
how many representative particles are there in 5 mole h2o
Sunday, August 7, 2016 by daling

chemistry assignment
A laboratory instructor gives a sample of amino acids powder to each students,1,2,3and4,and they weigh the samples.The true. value is 8.72g.Their results for three trials are 1:8.72g,8.74g,8.70g 2:8.56g,8.77g,8.83g 3:8.50g,8.48g,8.51g 4:8.41g,8.72g,8.55g.(a)calculate the ...
Sunday, August 7, 2016 by Roberta

chemistry
which acid produces brown fume on heating?
Friday, August 5, 2016 by springdale

Chemistry
Consider the following reaction between sulfur trioxide and water: SO3(g)+H2O(l)→H2SO4(aq) A chemist allows 61.5 g of SO3 and 11.2 g of H2O to react. When the reaction is finished, the chemist collects 51.0 g of H2SO4. Determine the percent yield for the reaction.
Friday, August 5, 2016 by Anonymous

Chemistry
Equal weight of methane and hydrigen are mixed in an empty container at 25°C. The fraction of the total pressure exerted by hydrogen is
Friday, August 5, 2016 by Mani

Chemistry
How many grams of NaCl are presented in 250g of salt solution containing 9% NaCl?
Thursday, August 4, 2016 by Jessel

Chemistry
100g of calcium carbonate was decomposed by heating to produce 45g of calcium oxide and carbon dioxide, using the equation given, calculate the Percentage Yield of Calcium Carbonate. CaCO3 -------> CaO + CO2 Please help me i tried working out but kept on getting stuck after...
Thursday, August 4, 2016 by Tanmay

Chemistry
Lipoprotein is a technique for removing fat deposits from various areas of the body. How many liters of fat would have to be removed to result in a 5.0 IB weight loss? The density of human fat is 0.94 g/mL.
Wednesday, August 3, 2016 by Maddie North

chemistry
why is helium considered a noble gas?
Wednesday, August 3, 2016 by Anonymous

Analytical Chemistry
This question pertaining to buffer systems! How would you prepare 10.0mL of 0.0100M phosphate buffer, pH = 7.4 0, from stock solution of 0.100M KH2PO4 and 0.250M K2HPO4, pKa of KH2PO4 is 7.20. Please help me in figuring out how I even start this problem...as well as attempting...
Wednesday, August 3, 2016 by Katie

chemistry
calculate the mass of potassium hydrogen phthalate needed to prepare a 0.1M solution in a 250 ml volumetric flask given that the molar mass of potassium hydrogen phthalate is 204,23g/mol
Wednesday, August 3, 2016 by Sam

Chemistry
Death Valley in California is 86 m below sea level. Will the partial pressure of oxygen in Death Valley be the same, lower or higher than the partial pressure of oxygen at sea level? A. higher B. impossible to tell without additional information C. the same
Wednesday, August 3, 2016 by SahDuuude

Chemistry
The gas in a cylinder has a volume of 8 liters at a pressure of 108 kPa. The pressure of the gas is increased to 224 kPa. Assuming the temperature remains constant, what would the new volume be?: _______L How would I go about solving this particular problem? Thanks! :)
Wednesday, August 3, 2016 by SahDuuude

Chemistry
Describe how lead(II) iodide cen be prepared in the laboratory
Tuesday, August 2, 2016 by Aaron

Chemistry
Rearrange the titration calculation to find Mb in a solution. If I put 13.2 mL of NaOH and 0.3 mL of phenolphthalein in 25 mL of KHP, what is the Mb of the solution? The original solution of NaOh is 100 mL and is composed of 1.069e-15 moles of H+, 9.445e-2 moles of OH-, and 9....
Tuesday, August 2, 2016 by Jenny

Chemistry
sample of silver metal is suspected to be contaminated with zinc. A 0.2365 g portion of this metal is dissolved in nitric acid and the silver ions precipitated with excess aqueous NaCl. After filtering and drying, the mass of the precipitate is found to be 0.2865 g. What was ...
Tuesday, August 2, 2016 by Damon

Chemistry
Mercury has a melting point of - 38. 9°C. what would this read in degrees Fahrenheit the and kelvin
Tuesday, August 2, 2016 by Ruth Ekada

Chemistry
The following soluble salts are strong electrolytes. For each, write a balanced equation for their dissociation in water. NaBr BaBr2 Li3PO4
Tuesday, August 2, 2016 by Katie

Chemistry
If the pH of a 0.46 M aqueous solution of a weak base is 9.2, estimate the Kb of the base:
Monday, August 1, 2016 by Damon

analytical chemistry
what is the solubility of PbI2in g/L ,if the solubility product is 7.1 ?
Monday, August 1, 2016 by Uzma Jan

analytical chemistry
the solubility product of Bi2S3 is 1.0 and that of HgS is 1.0. which one is the least soluble under a given temperature 6
Monday, August 1, 2016 by Uzma Jan

chemistry
Consider the titration of 40.0 mL 0.250 M ethylamine, C2H5NH2, with 0.350 M HCl. Determine each of the following and sketch the titration curve. Kb of ethylamine = 5.6x 10-4 a. The volume of added acid required to reach the equivalence point. b. The initial pH. c. The pH when ...
Sunday, July 31, 2016 by danna

chemistry
what amount of ammonium chloride that will separate out when 55g of its solution at 373k is cooled to 273k(solubility at 373k -55g and at 273k - 37g)
Sunday, July 31, 2016 by anamika

Chemistry
1.5mL of a 0.05M solution of calcium chloride (CaCl2) was diluted with water to a volume of 10L. What was the concentration of Cl- ions in the diluted solution in ppm.
Sunday, July 31, 2016 by Rav

Chemistry
What is Anta basic substance?
Sunday, July 31, 2016 by Utsav

chemistry
In which direction, on ceiling, floor or walls, the pressure exerted by air in a room will be maximum. Justify your answer
Saturday, July 30, 2016 by Anonymous

Chemistry
An antifreeze solution is prepared containing 40.0 g of ethylene glycol (molar mass = 62.0 g/mol) in 60.0 g of water. Calculate the freezing point of this solutions A.-20.1°C B.0.518°C C.20.1°C D.120.1°C
Saturday, July 30, 2016 by Jessie

Chemistry
Write chemical formulas for the compounds formed by the following positive and negative ions: Ba2+ and NO3-, Al3+ and Co3, and K+ and PO43-
Saturday, July 30, 2016 by Kelly

Chemistry
If you start with 4.00 moles of C3H8 (propane) and 4.00 moles of O2, how many moles of carbon dioxide can be produced?
Friday, July 29, 2016 by Kelly

Chemistry
Electrochemistry In the electrolysis of aqueous copper(II) bromine CuBr2(aq, 1.00 g of copper is deposited at the cathode. How many grams of bromine are produced at the anode?
Friday, July 29, 2016 by sarah simpson

Chemistry
What are 2 allotropes of carbon? Could you please compare the physical and chemical properties....
Friday, July 29, 2016 by Sarah

Chemistry
How do you determine the polarity of a substance? Example?
Friday, July 29, 2016 by George

Chemistry Theory
We are able to "see" the shapes of molecules with X-ray crystallography. However, even without this technology, there is a great deal of evidence that water, H2O, is a bent, polar molecule. Discuss this evidence and explain how it relates to our model of the water ...
Friday, July 29, 2016 by Katie

chemistry
Using dissociation constants from Appendix D in the textbook, determine the value for the equilibrium constant for each of the following reactions. (Remember that when reactions are added, the corresponding equilibrium constants are multiplied.) (i) HCO−3(aq)+OH−(...
Friday, July 29, 2016 by sayuri

Chemistry
Downlad Project
Friday, July 29, 2016 by Project

Chemistry
if the solubilty of AgC2H3O2 is 5.0 x10^-2mol/L. What is the Ksp?
Friday, July 29, 2016 by Kevin

Chemistry
if 1.7L of a saturated solution of AgC2H2O2 is found to contain 14.1g of AgC2H3O2. What is the Ksp of AgC2H3O2?
Friday, July 29, 2016 by Shirley

Chemistry
A voltaic cell, with Ecell = 0.180 V at 298K, is constructed as follows: Ag(s)|Ag+(satdAg3PO4)||Ag+(0.135 M )|Ag(s) What is the Ksp of Ag3PO4?
Friday, July 29, 2016 by LC

Chemistry 12th
How can you prepared to benzo phenol from phenyl magnetium bromide
Friday, July 29, 2016 by Chemistry

Chemistry
Calculate the pH of the buffer formed by mixing 50.0mL of 0.200 F NaH2PO4 with 50.0mL of 0.120 F HCl
Friday, July 29, 2016 by Wynona Genesis

Chemistry
A 50.0 mL solution with analytical concentration of 0.100M in HClO4and 0.080M in formic acid is titrated with 0.200M KOH. Calculate the pH after addition of the following volumes of titrants: a) 0.0, b)20.0, c) 25.0, d)35.0, e)45.0, f)50.0
Friday, July 29, 2016 by Wynona Genesis

Chemistry
A glass of water contains 1.2 x 1024 molecules of water. An additional 4.0 moles of water are poured into the glass. How many moles of water are in the glass?
Thursday, July 28, 2016 by Kelly

chemistry
How to solve CoCl2+HO2- ------> Co(OH)3+ Cl- by half reaction method
Thursday, July 28, 2016 by Pratik Rathi

Chemistry
C2D3 has a solubility product constant of 9.14×10−9. What is the molar solubility of C2D3? Express your answer with the appropriate units.
Thursday, July 28, 2016 by Damon

Chemistry
How many grams of Nitrogen contains same number of neutrons as 6grams of 12C?
Thursday, July 28, 2016 by Anurag Barman

Chemistry
How much heat is produced by the complete reaction of 5.29 kg of nitromethane?
Thursday, July 28, 2016 by Isaac

General Chemistry
what is the value of Kc if PbCl(s)=1.5g, [Pb2+]=1.6*10^-2 M and [Cl-] =3.2*10^-2 M at equilibrium? (The molar mass of PbCl(s) is 278 g/mol and its density is 5.85g/cm^3.)
Thursday, July 28, 2016 by Anonymous

Chemistry
What is the concentration of a monoprotic weak Acid if its pH is 5.50 and its Ka= 5.7 x 10^-10?
Thursday, July 28, 2016 by Joshua

Chemistry Grade 12
If the concentration of I^-1 is found to be 2.4 x 10^-3 mol/L in a saturated solution of PbI2. What is the Ksp of PbI2?
Thursday, July 28, 2016 by Kevin

Chemistry
Why wash water in experiment limiting reagent has to be kept warm at 80-90 degree celcius . Explain why
Thursday, July 28, 2016 by Uitm

Chemistry
I need to draw a line angle structure of ibuprofen that shows hydrogen bonding and I am stuck. Can anyone help?
Wednesday, July 27, 2016 by Breanne

Chemistry
You discover a new cell type that contains measurable amounts of silver ions (Ag+) in it. You find that the concentration of Ag+ inside the cell is still 10 times lower than the concentration outside. Calculate the amount of membrane potential that results from this amount of ...
Wednesday, July 27, 2016 by Tenshi

Organic Chemistry
Is helium considered a noble gas?
Wednesday, July 27, 2016 by Anonymous

  1. Pages:
  2. <<Prev
  3. 1
  4. 2
  5. 3
  6. 4
  7. 5
  8. 6
  9. 7
  10. 8
  11. 9
  12. 10
  13. 11
  14. 12
  15. 13
  16. 14
  17. 15
  18. Next>>

Homework Help: Science