Wednesday
December 7, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Mg + HCl -------> MgCl2 + H2 What volume of HCl is required from 27 % HCl to form 12.1 gram H2? ( D = 1.41 g/ml)
Friday, September 2, 2016 by Majid

Chemistry
how many joules of energy are needed to change 400 grams of water from 35 degrees C to 45 degrees C?
Thursday, September 1, 2016 by helpneeded

Chemistry
Calculate the volume of 1.0 M CuSO4 stock solution you should use to make 100 mL of a 0.010 m CuSO4 solution.
Thursday, September 1, 2016 by Brianna

Chemistry
How do I calculate the amounts of Na2SO4 and CaCl2 that I need to create a solution of CaSO4 at 9 grams/Liter concentration?
Thursday, September 1, 2016 by Kato

Chemistry
How many electrons in CH3NH3+ ?
Thursday, September 1, 2016 by anon

Chemistry
Which is a conjugate pair in the following equilibrium? H2C2O4(aq) + HPO4(aq) 2- HC2O4(aq)- + H2PO4(aq)-
Thursday, September 1, 2016 by Aidan

biology
which of the following is consistent with the theory of vitalism ? A.all matter contains a vital force** b.the chemistry of life and nonlife are similar c. living things contain a vital force absent in nonliving things d. life must be sustsained through a series of chemical ...
Thursday, September 1, 2016 by 9th grader

biochemistry
which of the following is consistent with the theory of vitalism ? A.all matter contains a vital force** b.the chemistry of life and nonlife are similar c. living things contain a vital force absent in nonliving things d. life must be sustsained through a series of chemical ...
Thursday, September 1, 2016 by 9th grader

chemistry
From a laboratory process designed to separate water into hydrogen and oxygen gas, a student collected 10.2 g of hydrogen and 66.9 g of oxygen. How much water was originally involved in the process?
Thursday, September 1, 2016 by melissa

Chemistry(please check my answer)
Which of the following is an oxidation reaction? A. AuCl4- → AuCl 2- **** B. Mn7+ → Mn2+ C. Cl2 → ClO3- D. Co3+ → Co2+
Thursday, September 1, 2016 by Cherry

Chemistry(please check my answer)
Among the following, which is an oxidation-reduction reaction? A. Na2S + CaCO3 → CaS + Na2CO3 B. 2HNO3 + Mg(OH)2 → Mg(NO3)2 + 2H2O C. H2 + F2 → 2HF**** D. 3Ba(OH)2 + 2H3PO4 → Ba3(PO4)2 + 6H2O
Thursday, September 1, 2016 by Cherry

Chemistry(please check my answer)
When the equation HCl + MnO2 → MnCl2 + H2O + Cl2 is balanced, what is the coefficient for HCl? A. 1 B. 2 C. 3 D. 4***
Thursday, September 1, 2016 by Cherry

Chemistry (please check my answer)
Identify a false statement about how to protect iron from corrosion. A. Coat the surface with oil, paint, or plastic. B. Attach a metal that is more easily reduced. ******* C. Exclude air and water. D. Attach a metal that is a better reducing agent.
Thursday, September 1, 2016 by Cherry

intergrated rate law chemistry
The decomposition of ammonia on a platinum surface at 1129 K occurs according to the following reaction: 2NH3 (g) ¨ N2(g) + 3H2(g). Use the following kinetic data which report the variation of ammonia concentration in the gas phase with time to evaluate the order of ...
Thursday, September 1, 2016 by chancy xdicey

chemistry
12M HCl + H20→ 5M HCl How much water? Total Volume= Pls I need this tomorrow
Thursday, September 1, 2016 by jack

Chemistry
Which of the following is true concerning the reaction below? H2S + HNO3 → S + NO + H2O A. S is reduced. B. H is oxidized. C. N is reduced. D. O is oxidized. ***
Wednesday, August 31, 2016 by Cherry

chemistry
it was found that in an experiment tthat a gas c diffuses 8.76¡Á10^-1 times faster than nitrogen gas calculate the molecular mass of gas c (n=14)
Wednesday, August 31, 2016 by saara

Chemistry
When 38.21 g of pure copper reacts with 192.83g of iodine, 190.83g of a compound containing only copper and iodine result. 40.21g of iodine remain when the reaction is complete. a. Do these results support the Law of Conservation of Mass? Explain. b.does this compund obey the ...
Tuesday, August 30, 2016 by Anonymous

Chemistry
Oxy acetylene welding uses acetylene gas which is produced by the reaction of CaC2 with water. It also produces calcium hydroxide as a by product.Calculate the volume in liters measured at 27°C and 965 torr that would be produced from the complete reaction of 11.2 g of ...
Tuesday, August 30, 2016 by Vaidehi

Chemistry
If a 29.9 g sample of the liquid cyclohexane has a volume of 38.6 mL, what is the specific gravity of the compound? Take the density of water to be 1.00 g/mL.
Tuesday, August 30, 2016 by Abby

Chemistry
A Helium Gas Ballon Has A Volume Of 12.0L. At Room Temperature(25 Degrees Celcius) The Internal Pressure Is .05ATM. Calculate The Number Of Moles Of Helium In The Balloon?
Tuesday, August 30, 2016 by Steve

Science, chemistry
During the experiment, 100ml will be required to prepare 0.5M solution of NaNO3. Calculate the mass of NaNO3 in grams that will be required.
Tuesday, August 30, 2016 by Hilen

chemistry
Answer the following questions about Fe(NO3)3. a. What is the mass percent of iron in this compound? b. A different iron compound is 34.43% by mass iron. What mass of this compound is needed to get 125g of pure iron?
Monday, August 29, 2016 by Alissa L

Chemistry
A 100.00g sample of the gaseous hydrocarbon ethane is a gaseous hydrocarbon, with 79.89g of carbon and 20.11g of hydrogen. Ethylene is a different gas phase hydrocarbon. A 100.00g sample of ethylene has 85.63g of carbon with 14.37 of hydrogen. A sample of a hydrocarbon has 64....
Monday, August 29, 2016 by Alissa L

Chemistry
At normal temperature and pressure, air has a density of 0.001184 g/mL. What is the mass of air in a room that is 3.93 m by 2.28 m by 2.25 m?
Monday, August 29, 2016 by Melanie

Chemistry
A solution is 40% acetic acid by mass. The density of this solution is 1.049 g/mL. Calculate the mass of pure acetic acid in 460 mL of this solution at 20 C. Answer in units of g.
Monday, August 29, 2016 by Melanie

Chemistry
I have no idea how to solve this problem could someone explain it to me please What will be the approximate volume when the temperature is 900 kelvin?
Monday, August 29, 2016 by Zoella

chemistry
What is the solubility of BaSO4 in a solution of 0.250 M Na2 SO4 ? The Ksp of BaSO4 is 8.7 x 10-11.
Monday, August 29, 2016 by elaine haizel

Chemistry
A salt water swimming pool is 47.0 m long, 25.1m wide, and 2.79 m deep. If the pool is filled with salt water having a density of 1.06 g/ cm3, how many pounds of salt water are in the pool when it is filled? 1 kg = 2.20 lb I'm not sure how to approach this. I've tried ...
Monday, August 29, 2016 by Jamie

chemistry
C2O4-- + I- + H+ ---> I2+CO2+H2O
Monday, August 29, 2016 by Vinay Pratap Singh

Organic Chemistry
The pKa of CH3COOH is 4.76. What statement describes a solution of CH3COOH at pH of 6.4?
Sunday, August 28, 2016 by Anonymous

Chemistry
7. A 100.00g sample of the gaseous hydrocarbon ethane is a gaseous hydrocarbon, with 79.89g of carbon and 20.11g of hydrogen. Ethylene is a different gas phase hydrocarbon. A 100.00g sample of ethylene has 85.63g of carbon with 14.37 of hydrogen. A sample of a hydrocarbon has ...
Sunday, August 28, 2016 by Alissa L

Bio physics chemistry pre medical
Methane react with steam to form h2 and co. . what volume of h2 can be obtained from 100cmcube of methane at the standard temperature and pressure? ?
Sunday, August 28, 2016 by Hania

Bio physics chemistry pre medical
The vitamin a has a molecular formula c 20 h 30 o. How much no of molecules will be vitamin a has in 500mg capsule?
Sunday, August 28, 2016 by Anonymous

Bio physics chemistry pre medical
Vitamin a has a molecular formula c 20 h 30 o. How much no of molecules will vitamin a contian in 500mg capsule? ? Plz tell me now tomorrow is my test .I will be very grateful of u. .
Sunday, August 28, 2016 by Hania

Chemistry
Dissolved 0.7500 g calcium chloride dihydrate and impure, in distilled water and the volume was elevated to 200.00 mL in a volumetric flask. A rate of 10.00 mL of the same consumed the titration 18.9 mL 0.0125 M EDTA using CALCON as indicator. What is the purity of the salt...
Sunday, August 28, 2016 by Damon

Chemistry
How many potassium ions are present in the following: 1) 3 moles of potassium chloride.
Sunday, August 28, 2016 by Nicole

Bio physics chemistry pre medical
Vitamin a has a molecular formula c 20 h 30 o. How much no of molecules will vitamin a contian in 500mg capsule? ? Plz tell me now tomorrow is my test .I will be very grateful of u. .
Sunday, August 28, 2016 by Hania

Bio physics chemistry pre medical
Methane react with steam to form h2 and co. . what volume of h2 can be obtained from 100cmcube of methane at the standard temperature and pressure? ?
Sunday, August 28, 2016 by Hania

Chemistry
if 12.8g of NaCl is added to 243.2 mL of water (density (1.00g/mL)). the volume occupied by the solution is 250.0 mL. Calculate the density of the salt water.
Sunday, August 28, 2016 by Anonymous

Chemistry
The weight of kclo3 which thermal decomposition o2 gas sufficient for the combustion of 1.12 litres of ethlene gas at STPis
Sunday, August 28, 2016 by Anonymous

Chemistry
One volume of a hydrocarbon require 3 volume of oxygen for complete combustion then formula for hydrocarbon
Sunday, August 28, 2016 by Anonymous

Chemistry
How many electrons involved in the reduction of one mole of Al2o3 to aluminium metal
Sunday, August 28, 2016 by Anonymous

Chemistry
How many moles of potassium permanganate is necessary to oxidise o.5 moles of soadium sulphate in acid medium
Saturday, August 27, 2016 by Anonymous

Chemistry
A flask of known volume was filled with air to a pressure of 3.6atm. This flask was then attached to an evacuated flask of known volume and the air was allowed to expand into the flask. The final pressure of the air (in both flasks) was 2.7atm and the volume of the second ...
Saturday, August 27, 2016 by Scott

Chemistry
Dissolved 0.7500 g calcium chloride dihydrate and impure, in distilled water and the volume was elevated to 200.00 mL in a volumetric flask. A rate of 10.00 mL of the same consumed the titration 18.9 mL 0.0125 M EDTA using CALCON as indicator. What is the purity of the salt...
Saturday, August 27, 2016 by Damon

Chemistry
Hello, please I need help with this excersice of chemical equilibrum. I really don't get what "1:6" means and how can I use that proportion". The excercise says: "0,014" moles of HCl are dissolved in water in a proportion of 1:6 (1 mole of HCl per ...
Saturday, August 27, 2016 by Nelson

Chemistry
Why is the heat of neutralization between HCL and NaOH is higher than CH3COOH and NaOH
Saturday, August 27, 2016 by Christian Dadzie

Chemistry
Dissolved 0.7500 g calcium chloride dihydrate and impure, in distilled water and the volume was elevated to 200.00 mL in a volumetric flask. A rate of 10.00 mL of the same consumed the titration 18.9 mL 0.0125 M EDTA using CALCON as indicator. What is the purity of the salt...
Friday, August 26, 2016 by Damon

Chemistry
Dissolved 0.7500 g calcium chloride dihydrate and impure, in distilled water and the volume was elevated to 200.00 mL in a volumetric flask. A rate of 10.00 mL of the same consumed the titration 18.9 mL 0.0125 M EDTA using CALCON as indicator. What is the purity of the salt...
Friday, August 26, 2016 by anon

chemistry
how to differenciate potassium carbonate from calcium carbonate in terms of deliquiscence,hygroscopy and efflorescence
Friday, August 26, 2016 by asa

chemistry
how to differenciate potassium carbonate from calcium carbonate in terms of deliquiscence,hygroscopy and efflorescence
Friday, August 26, 2016 by asa

Chemistry
How Many Atoms Are There In 10grams Of Carbon
Thursday, August 25, 2016 by Seyi

Chemistry
How Many Atoms Are There In 10grams Of Carbon And How Many Molecules Are There In 10grams Of Calcium Carbonate
Thursday, August 25, 2016 by Mickid

chemistry
A solution is made by mixing 25 mL of .35 M LiOH with 15.5 mL of .2225 M NH3. Kb=1.8x10^-5 for NH3 Calculate the pH for the solution.
Thursday, August 25, 2016 by sara

chemistry
2.2. Billions of kilograms of urea, are produced annually for use as a fertilizer. The reaction used is given below. NH3(g) + CO2(g) → CO(NH2)2(s) + H2O(l) The typical starting reaction mixture has a 3:1 mole ratio of NH3 to CO2. If 47.7 g urea forms per mole of that ...
Wednesday, August 24, 2016 by mandla

Chemistry
Which of the following would be the best to measure 18mL of acohol accurately and precisely
Wednesday, August 24, 2016 by Miekyela

Chemistry
One hundred grams of mixture of NaSO4 – 10H2O and Na2CO3 – 10H2O are heated to drive off water of hydration. The final weight of the mixed salts is 39.6g. What is the ration of moles Na2CO3 to moles Na2SO4 in the original hydrated salts?
Wednesday, August 24, 2016 by Neshen

Chemistry
25.0 mL of an H3BO3 solution were titrated with 29.15 mL of a 0.205 M LiOH solution to reach the equivalence point. what is the molarity of the H3BO3 solution?
Tuesday, August 23, 2016 by Kat

chemistry
how much NAOH must be added to 500ml acetic acid 0.5Mol to give ph 0.5
Tuesday, August 23, 2016 by elie king

Chemistry
A 2.80-g sample of haematite ore containing Fe3+ ions was dissolved in a concentrated acid and the solution was diluted to 250 mL. A 25.0 mL aliquot was reduced with Sn2+ to form a solution of Fe2+ ions. This solution of Fe2+ ions required26.4mL of a 0.0200 M K2Cr2O7 solution ...
Tuesday, August 23, 2016 by Luke

chemistry
how to balance combustion of 5% by volume in air. 1. 0.05 CH4 + ( )(0.21 O2 + 0.79 N2) 2. ( )CH4 + O2 + 0.376 N2
Monday, August 22, 2016 by skrishna

Chemistry
How many moles of chloride ions are in 0.04dm^3 of 0.45M calcium chloride CaCl2
Monday, August 22, 2016 by Florence

Chemistry
What mass of glucose (c6h12o6)is produced from 18g of co2 when it reacts with water molecule? 6Co2+6H2o→c6h12o6+Co2
Monday, August 22, 2016 by Nasir khan

Chemistry
What is the mole fraction of ethanol, C2H5OH, in an aqueous solution that is 50.0% ethanol by mass?
Monday, August 22, 2016 by Devon

chemistry
which of following show cistrans isomerism?
Monday, August 22, 2016 by ali

chemistry
The amount of sulphuric acid (in gm) required to neutralise 10L of ammonia at STP is
Monday, August 22, 2016 by Hamza

Chemistry
There are three naturally occurring isotopes of the hypothetical element hilarium 41Hi, 42Hi, and 44Hi. The percentages of these isotopes are the following: Hilarium Natural Isotopes Abundance 41Hi 18.7% 42Hi 43.6% 44Hi 37.7% You can assume that the atomic masses are exactly ...
Monday, August 22, 2016 by anonymous

chemistry
When 25 mL of C2H5OH (density 0.80 g.cm-3) is dissolved in water to prepare a 250 mL solution, the density of the solution was found to be 0.950 g.cm-3. Calculate a. Molarity of pure ethanol; b. Molarity of ethanol in the final solution; c. Volume of the final solution which ...
Monday, August 22, 2016 by avni

chemistry
What is the equilibrium expression for the following acid dissociation reaction? CH3COOH + H2O CH3COO- + H3O+ A. [CH3COO-][H3O+]/[CH3COOH][H3O] B. [CH3COOH][H2O]/[CH3COO-][H3O+] C. [CH3COOH]/[CH3COO-][H3O-] D. [CH3COO-][H3O+]/[CH3COOH]
Monday, August 22, 2016 by jessie

chemistry
A reaction has an equilibrium constant very much less than 1. Will the reaction proceed spontaneously? A. Yes, because products are favored and deltaG° < 0. B. Yes, because reactants are favored and deltaG° > 0. C. No, because reactants are favored and deltaG°...
Monday, August 22, 2016 by jessie

chemistry
If the equilibrium constant is much less than 1, how can you tell where the equilibrium lies? A. Reactants are in the numerator of the equilibrium expression, so equilibrium lies toward the reactants. B. Products are in the numerator of the equilibrium expression, so ...
Monday, August 22, 2016 by jessie

chemistry
What information does an equilibrium constant give about a reaction? A. It tells how long it takes the reaction to reach equilibrium. B. It tells how much energy is required for the reaction to happen. C. It tells what the rate constant of the reaction is at equilibrium. D. It...
Monday, August 22, 2016 by jessie

Chemistry
determine the ph of 5 grams KNO3 that is dissolved in 100ml water.KNO3 is produced by mixing .2M KOH and 0.2M HNO3...please help me...pls..
Sunday, August 21, 2016 by Jonalyn

Chemistry
determine the ph of 5 grams KNO3 that is dissolved in 100ml water.KNO3 is produced by mixing .2M KOH and 0.2M HNO3...please help me...
Sunday, August 21, 2016 by Jonalyn

chemistry
A piece of zinc was added to 1000cm³ of 0.2m hydrochloric acid. After effervescence head stopped, 30cm³ of the resulting solution required 22cm³ of 0.08m sodium trioxocarbonate (iv) solution for complete neutralization, calculate the mass of zinc added.
Sunday, August 21, 2016 by victor Ilevbare

chemistry
P4 + HNO3 = H3PO4 + NO2 + H20 by partial method balancing
Sunday, August 21, 2016 by Durgesh

chemistry
If your favorite silver jewelry ever tarnishes and you happen to have some aluminum foil on hand, you can actually get rid of some of that tarnish. The tarnish here is actually silver sulfide. If you put the jewelry and aluminum into a dish with enough water to cover them both...
Sunday, August 21, 2016 by student in revolt

Science Chemistry
Calculate the no. of grams of NaOH req. to absorb volume of the CO2 gas produce as Na2CO3
Sunday, August 21, 2016 by Sumee

chemistry
how many moles of fe are present in 30g of rust?
Sunday, August 21, 2016 by ali

Chemistry
How many grams of KCl should be added to 1.5kg of water to lower its freezing point to -7.5°C
Sunday, August 21, 2016 by Anonymous

chemistry
When is there a need to determine G? A. When H > 0 and S < 0 B. When H > 0 and S = 0 C. When H > 0 and S > 0 D. When H = 0 and S < 0
Saturday, August 20, 2016 by sofie

science - chemistry
How can we separate a mixture of iodine, napthalene, chalk dust and saw dust. Write the ans in the form of a flow chart.
Saturday, August 20, 2016 by shaan

chemistry
what is the concentration of na and co3 ions in 0.2M aqueous solution of na2co3
Saturday, August 20, 2016 by Anonymous

chemistry help!!! please!!! DrBob222 I need you!!
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 I'm really very stuck with this question. please help me!!!
Saturday, August 20, 2016 by emma

chemistry help!!! please!!! DrBob222 I need you!!
The G value for formation of gaseous water at 298 K and 1 atm is -278 kJ/mol. What is the nature of the spontaneity of formation of gaseous water at these conditions? A. The reaction is sometimes spontaneous. B. The reaction is spontaneous. C. The reaction may or may not be ...
Saturday, August 20, 2016 by emma

CHEMISTRY
Why is glass considered as a supercooled liquid? answer please!!!
Saturday, August 20, 2016 by A GOODSTUDENT

chemistry
The reaction CHCL3(g)+CL2(g)_CCL4(g)+HCL(g) has the following rate law:Rate =k [CHCL3][CL2].If the concentration of CHCL3 is increased by a factor of five while the concentration of CL2 Is kept the same use a mathematical equation to show the factor by which the rate will ...
Saturday, August 20, 2016 by Felix

CHEMISTRY
why is glass called a supercooled liquid?
Saturday, August 20, 2016 by helpneeded

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

  1. Pages:
  2. <<Prev
  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
  16. 19
  17. 20
  18. Next>>

Homework Help: Science