Monday
August 3, 2015

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
The antacid in question (with an active ingredient of Ca(HCO3)2), upon treatment with excess hydrochloric acid, a 0.413 g sample gives 92.85 mL of CO2 at 25.00oC and 1.000 atm. What percentage of the antacid is active ingredient? Assume a perfect system (i.e. the yield is 100%)
Saturday, November 1, 2014 by kimberly

chemistry
a 0.96 millimole sample of Na2CO3 gave 0.9 millimoles of CO2 gas. If a 0.376 g of pure Na2CO3 was reacted with excess acid, what volume of gas will be measured on this apparatus
Saturday, November 1, 2014 by kimberly

College Chemistry
Please tell me what I did wrong on this problem: Given the equation Fe2O3(s)+3CO(g)→2Fe(s)+3CO2(g), Calculate the number of grams of CO that can react with 0.370kg of Fe2O3 Here's what I did: .370kg x 1000 = 370g of Fe2O3 370g/[(55.85 x 2) + (13 x 3)] = 2.32 mol 2.32...
Saturday, November 1, 2014 by Theresa

Chemistry
A 0.2800 g sample of an unknown acid requires 28.22 mL of 0.1199 M NaOH for neutralization to a phenolphthalein point. a.) How many moles of OH- are used? b.) How many moles of H+ are found in the acid? c.) What is the calculated equivalent molar mass of the unknown acid? If I...
Saturday, November 1, 2014 by Jess

chemistry
Complete the following reactions, where applicable. If no reaction occurs write N.R A) blank + blank ---> Cu(NO3)2 + PbSO4 B) C6H12O6 + O2 --> blank + blank C) AgNO3 + CuCI2 ---> blank + blank
Saturday, November 1, 2014 by Rosie

chemistry
convert the condensed formula to a complete and skeletal structure of the following formula (ch3)2chch2ch3
Saturday, November 1, 2014 by hensha

Chemistry
A meteorological balloon contains 237. L of helium at 33. °C and 0.832 atm. If the volume of the balloon can vary according to external conditions, what volume would it occupy at an altitude at which the temperature is -57. °C and the pressure is 0.094 atm? (2 ...
Saturday, November 1, 2014 by Anna

Chemistry
Suppose 55.3 L of a gas is at a temperature of -73. °C. If its temperature is increased to 411. °C, what will its volume be then?
Saturday, November 1, 2014 by Anna

Chemistry
If you weighed out 0.38 grams of calcium and reacted it with excess amount of HCI how many miles of H2 grams would you expect to produce?
Saturday, November 1, 2014 by Joann

Chemistry
Calculate the solubility of Kcl2 in mole per dm cube of water at 90 dgree celcius if 10grams of the solute will saturate 20grams of water
Saturday, November 1, 2014 by Oreoluwa

Chemistry
What is the density, in grams per milliliter, of a salt solution if 210 mL has a mass of 234 g?
Friday, October 31, 2014 by Gili

chemistry
What is the volume occupied by 0.252mol of helium gas at 1.35atm and 305K ?
Friday, October 31, 2014 by Anon

chemistry
A bag of potato chips contains 575mL of air at 25.0∘C and a pressure of 765mmHg . Assuming the bag does not break, what will be its volume at the top of a mountain where the pressure is 458mmHg and the temperature is 10.0∘C?
Friday, October 31, 2014 by Anon

chemistry
A balloon contains 0.126mol of gas and has a volume of 2.78L. If an additional 7.0×10−2mol of gas is added to the balloon, what will its final volume be?
Friday, October 31, 2014 by Anon

chemistry
A 813. mL sample of argon gas at 452. K is cooled at constant pressure until the volume becomes 356. mL. What is the new gas temperature in Kelvin?
Friday, October 31, 2014 by Anonymous

chemistry
Calculate the pressure, in atmospheres, of 0.0495 mol of a gas in a 0.379 L flask at 23. oC.
Friday, October 31, 2014 by Shatoya

chemistry
A chamber has a volume of 17 m3 and operates at a pressure of 4.66 atm. What volume in cubic meters would the air in the chamber occupy if the pressure were changed to 1.64 atm at constant temperature?
Friday, October 31, 2014 by Shatoya

chemistry
What is the mass of 5.33 mol Fe2(SO4)3? Answer in units of g
Friday, October 31, 2014 by kayy

chemistry
How much does 1.9 mol of carbon dioxide weigh? Answer in units of g
Friday, October 31, 2014 by kayy

chemistry
V1= 38.8 n1= 1.60*10^-3 V2= 49.9 n2= ? How do we solve for n2 using avogadro's law?
Friday, October 31, 2014 by Luis

Chemistry
A 0.2800 g sample of an unknown acid requires 28.22 ml of 0.1199 M NaOH for neutralization to a phenolphthalein end point. a.) How many moles of OH- are used? b.) How many moles of H+ are found in the acid? c.) What is the calculated equivalent molar mass of the unknown acid? ...
Friday, October 31, 2014 by Jess

Chemistry
Calculate the kinetic energy of the photoelectron emitted by a metal (threshold energy is 1.50 x 10^-19J) exposed to light of wavelength 5.00 x 10^-7 m (the energy beyond that required to knock electron goes into electron kinetic energy). A) -3/98 x 10^-19J B) 3.98 x 10^-19J C...
Friday, October 31, 2014 by Anonymous

Chemistry
We have of ice at -11.9°C and it is ultimately completely converted to liquid at 9.9°C. For ice, use a specific heat (Cs) of 2.01 J/gK, for liquid water use a specific heat of 4.18 J/gK, and ΔHfusion = 6.01kJ/mole, Molar mass H20 = 18.01g/mol. If 1 mole of ice at...
Friday, October 31, 2014 by Anonymous

chemistry
We have of ice at -11.9°C and it is ultimately completely converted to liquid at 9.9°C. For ice, use a specific heat (Cs) of 2.01 J/gK, for liquid water use a specific heat of 4.18 J/gK, and ΔHfusion = 6.01kJ/mole, Molar mass H20 = 18.01g/mol. If 4.19x10^3 kJ is ...
Friday, October 31, 2014 by Thanh

Organic Chemistry
1) Calculate the partition coefficient of caffeine in water/methylene chloride from the following data: 10.3 g/100 mL for methylene chloride and 2.04 g/100 mL for water. 2. A student is sure that 0.500 grams of caffeine is dissolved in 125 mL of water. The student extracts the...
Friday, October 31, 2014 by Jaimie

chemistry
How many moles of Ca(OH)2 are in 4.10 kg of Ca(OH)2? Answer in units of mol
Friday, October 31, 2014 by abby

chemistry
How many molecules are in 105 g of sugar (C12H22O11)? Answer in units of molec
Friday, October 31, 2014 by lily

Organic Chemistry
Calculate the partition coefficient of caffeine in water/methylene chloride from the following data: 10.3 g/100 mL for methylene chloride and 2.04 g/100 mL for water. Using the same data a student follows our procedure and extracts the caffeine using 3 extractions of 7 mL of ...
Friday, October 31, 2014 by Lola

Organic Chemistry
In a very controlled experiment, a student is sure that 0.500 grams of caffeine is dissolved in 125 mL of water. The student extracts the caffeine using a single extraction of 21 mL of methylene chloride. How much caffeine is in the methylene chloride? How much remains in the ...
Friday, October 31, 2014 by Lola

chemistry
advantage of potentiometric titration over other titrimetric titiration
Friday, October 31, 2014 by pranshu

chemistry
Imagine that you have an ideal gas in a 8.00L container, and that 2850 molecules of this gas collide with a square-inch area of the container at any given instant. If the volume is increased to 56.0L at constant temperature, how many collisions will occur per square inch of ...
Thursday, October 30, 2014 by Luis

Chemistry
2.562 g of H2C2O42H2O (s) was obtained and dissolved in enough DI water to form 150.0 mL of solution. What is the concentration of the resulting of H2C2O4 (aq) solution?
Thursday, October 30, 2014 by John Blake

Chemistry
In a constant-pressure calorimetry experiment, a reaction gives off 20.8 kJ of heat. The calorimeter contains 150 g of water, initially at 21.4 degrees Celsius. What is the final temperature of the water? The heat capacity of the calorimeter is negligibly small.
Thursday, October 30, 2014 by Megan

Chemistry
What is the product of NaC2O4 and Ag+? A. NaC2O4 and Ag+ do not form a product. B. AgNaC2O4 C. Ag2C2O4****** I think the right answer is C...please let me know - I asked once earlier but no one answered - thought I would try again.
Thursday, October 30, 2014 by Cassie

Chemistry
A chemical formula shows the types and __blank__ of atoms in the smallest representative unit of a substance.
Thursday, October 30, 2014 by Bridget

Chemistry
Beryllium flouride's formula is BeF2. Why do beryllium and flourine combine in a 1:2 ratio?
Thursday, October 30, 2014 by Ashley

chemistry
2CH3OH(l)+3O2(g)→2CO2(g)+4H2O(g Part B Calculate the standard enthalpy change for the combustion of 1 mol of liquid methanol, assuming H2O(g) as a product. Part C Calculate the heat produced by combustion per liter of methanol. Methanol has a density of 0.791 g/mL. Part ...
Thursday, October 30, 2014 by how do i even start this?

Chemistry urgent
2CH3OH(g)→2CH4(g)+O2(g)ΔH=+25​2.8kJ How many kilojoules of heat are released when 38.8g of CH4(g) reacts completely with O2(g) to form CH3OH(g) at constant pressure?
Thursday, October 30, 2014 by ihatechem

chemistry
How many hydrogen atoms are in 833 grams of water? Answer in units of atoms
Thursday, October 30, 2014 by lily

Chemistry
How much heat is required to warm 1.60kg of sand from 22.0∘C to 100.0∘C? The heat capacity of sand is 0.84 J⋅g−1⋅K−1
Thursday, October 30, 2014 by Steve Smeck

chemistry
Which of the following solutions of glucose (C6H12O6) is isotonic with a 0.15 M NaCl solution? Question 24 options: 0.15%(w/v) 0.55%(w/v) 1.5%(w/v) 5.4%(w/v)
Thursday, October 30, 2014 by Janet

chemistry
Isotonic saline is 0.89% NaCl (w/v). Suppose you wanted to make 1.0 L of isotonic solution of NH4Cl. What mass of NH4Cl would you need? Question 23 options: 1.6 g 8.1 g 8.9 g 54 g
Thursday, October 30, 2014 by Randy

chemistry
A solution is prepared by dissolving 104.1 grams of barium chloride, BaCl2 in 1000. grams of water? What is the boiling point of this solution? [The boiling point elevation constant for water is 0.52°C/mole solute in 1000g of water]
Thursday, October 30, 2014 by Natalya

Chemistry
The question has been answered years ago but not how it is solved. I tried the combined gas law. Here is the question: A balloon originally had a volume of 4.39 L at 44 degrees celsius and a pressure of 729 torr. The balloon must be cooled ??? to reduce its volume to 3.78 L at...
Thursday, October 30, 2014 by Aaron

Chemistry
what mass of nitrogen gas is required to react completely with 2.79 of hydrogen gas to produce ammonia?
Thursday, October 30, 2014 by Whitney

chemistry
Which of the following pairs of liquids are miscible in all proportions? Question 3 options: ethanol and oil ethanol and water gasoline and water All of the above
Thursday, October 30, 2014 by Clair

chemistry
Which of the following is true regarding the solubility of gases in liquids? Question 4 options: Solubility decreases as temperature increases. Solubility increases as temperature increases. Solubility is unaffected by changes in temperature. None of the above
Thursday, October 30, 2014 by Travis

chemistry
A 0.052g sample of aluminium reacts with excess 6M HCL. A 48.3mL volume of hydrogen gas was collected over water at 22C and the pressure of the hydrogen gas was 751mmHg.calculate the aluminum percent purity in the sample. What volume of hydrogen gas at STP is produced from the...
Thursday, October 30, 2014 by jeffrisa

CHEMISTRY
When 10.8 g of Silver was reacted with Sulfur, 12.4 grams of product was produced (there was only one product). What is the empirical formula of the product?
Thursday, October 30, 2014 by X

CHEMISTRY
pka of xanthine monophosphate is 5.5. a certain experiment can detect all forms of solute molecule present in solution at greater then 10% of total solute concentration. at pH 7, the experiment will detect presence of?
Thursday, October 30, 2014 by VARSHA

chemistry
A sample of neon gas at 1.20 atm compresses from 0.250 L to 0.125 L. If the temperature is held constant, what is the final pressure?
Thursday, October 30, 2014 by Anonymous

Chemistry
Solubility Rules!! Homework problem I desperately need help with Solutions used: 6M HCl, 6M NaOH, 6M NH3, 3M H2SO4 Mixed with: Cr(NO3)3, Fe(NO3)3, Bi(NO3)3, Mg(NO3)2, Pb(NO3)2 please help me and tell me which form precipitates and which
Thursday, October 30, 2014 by Kelsey

chemistry
What is the pH of a 100g/l solution of potassium cyanide?
Thursday, October 30, 2014 by Joe Price

chemistry
Relative abundance of H-2 (deuterium) is 0.015% and O-18 is 0.20%. Calculate the number of D2O18 molecules in a 1mol of natural water sample?
Thursday, October 30, 2014 by Ruzzle

chemistry
qualitative organic analysis lab 1. Why is it important to have clean test tubes before running a test? Before which tests should acetone not be used to clean the test tubes? 2. Why run solubility tests before running the functional group classification tests? 3. Determine ...
Thursday, October 30, 2014 by Niah

chemistry
Calculate the concentrations of all species in a 1.22 M Na2SO3 (sodium sulfite) solution. The ionization constants for sulfurous acid are Ka1 = 1.4× 10–2 M and Ka2 = 6.3× 10–8 M.
Thursday, October 30, 2014 by anon

chemistry
Calculate the number of GRAMS of carbon dioxide (CO2) produced when 100 grams of methane (CH4) are completely burned in oxygen (O2).
Wednesday, October 29, 2014 by Jeremy

Chemistry
Consider the following reaction: 4NH3(g) +5O2(g) -->4NO(g) +6H2O(g) Suppose we have two flasks connected by a stopcock. In one flask, we have 2.0L of NH3(g) at a pressure of .500 atm. In the other flask, we have 1.00L of O2(g) at a pressure of 1.5atm. When the stopcock is ...
Wednesday, October 29, 2014 by Claire

Chemistry
The solubility of aluminum sulfate in water at 20degrees Celcius is 26.7g/100L. Calculate its molarity?
Wednesday, October 29, 2014 by Gina

Chemistry
A student reacted 0.500g of Pb(NO3)2 with 0.750g of KI according to the reaction, Pb(NO3)2(aq) + 2KI(aq)=PbI2(s) + 2KNO3(aq) A) How many moles of Pb(NO3)2 were used? B) How many moles of KI were used? C) How many moles of PbI2 would form, based on the moles of Pb(NO3)2 used? D...
Wednesday, October 29, 2014 by Gina

CHEMISTRY
A student combusted 0.500g of purified aluminum power with excess oxygen in an oxygen atmosphere according to the reaction, 4Al(s) + 3O2(g)= 2Al2O3(s) A) What is the limiting reactant? B) How many moles of Al were used? C) How many moles of Al2O3 would form, based on the moles...
Wednesday, October 29, 2014 by Gina

Chemistry (urgent)
1.Using Nerst, find the E of the cell for the dicromate redox system: A.under standard conditions. B.under neutral solutions instead of acid solutions. 2.Use Nerst and the hydrogen half equation to obtain an expression for pH.
Wednesday, October 29, 2014 by Kris

chemistry
Calculate the theoretical percentage of water present in cobalt (II) chloride hexahydrate, given that the molar mass is 237.93 g/mol and the molar mass of water in the compound is 108.12 g/mol. Question 8 options: 220% 50.5% 6% 45.4%
Wednesday, October 29, 2014 by Tia

chemistry
The solubility of sodium chloride (NaCl) was determined experimentally to be 35.7 g/ 100 g of water (H2O) at 200 C. How many grams of NaCl would dissolve in 50g of H2O at 200 C?
Wednesday, October 29, 2014 by Nelana

Chemistry
Calculate the enthalpy change for: C2H4(g) + H2 --> C2H6(g) delta Hrxn: H2(g) + 1/2O2 --> H2O (l) C2H4(g) + 3O2 --> 2H20(l) + 2CO2(g) C2H6(g) + 7/2O2(g) --> 3H20(l) + 2CO2(g) I know I have to flip the third reaction but I dont know what to do next
Wednesday, October 29, 2014 by Jessica

chemistry
If you have 22.46 mLs of a gas at STP, how many moles of gas do you have?
Wednesday, October 29, 2014 by Javier

Chemistry
1.Using Nerst, find the E of the cell for the dicromate redox system: A.under standard conditions. B.under neutral solutions instead of acid solutions. 2.Use Nerst and the hydrogen half equation to obtain an expression for pH.
Wednesday, October 29, 2014 by Kris

Chemistry
Explain what would happen to the color of a dilute solution containing FeCl4- if you added a solution of sodium chloride, NaCl.
Wednesday, October 29, 2014 by Anonymous

Chemistry
A sample of methane (CH4) gas contains a small amount of helium. Calculate the volume percentage of helium if the density of the sample is 0.70902 g/L t 273K and 1.00 atm. I know that the sample is at STP and that the 1 mole of gas under these conditions occupies 22.4L, but ...
Wednesday, October 29, 2014 by Chris

chemistry
2CH3OH(g)→2CH4(g)+O2(g)ΔH=+25​2.8kJ For a given sample of CH3OH, the enthalpy change during the reaction is 82.2kJ . How many grams of methane gas are produced?
Wednesday, October 29, 2014 by ihatechem

Chemistry
How much heat is required to raise the temperature of 68.0 g of AIF3 from 25 degrees celsius to 80.0 degrees celsius
Wednesday, October 29, 2014 by person

chemistry
500g urea aq. Sol. Has mole fraction 0.2 what is molality of sol.
Wednesday, October 29, 2014 by mohit

chemistry
At what temperature will the following reaction happen spontaneously, given that ΔH=8.91×103J and ΔS= –219.20 J/K? CaSO4(s) + 2HCl(g) → CaCl2(s) + H2SO4(l)
Wednesday, October 29, 2014 by Rosi

Analytical Chemistry
Suggest a range of sample masses for the indicated primary standard if it is desired to use between 35 and 45mL of titrant: (a) 0.175 M HClO4 titrated against Na2CO3(CO2 product) (b) 0.085 M HCl titrated against Na2C2O4 Na2C2O4-->Na2CO3+CO CO3(2-)+2H(+)-->H2O+CO2 (c) 0....
Wednesday, October 29, 2014 by Cherie

Chemistry
By what factor does the volume increase when An ideal gas is allowed to expand from 3.80 L to 32.3 L at constant temperature
Wednesday, October 29, 2014 by Dust

Chemistry 400/ Chem 1A
Assuming that the resolution of an electron microscope is equal to the deBroglie wavelength of the electrons used, what is the resolution of an electron microscope (in nm) when the electrons are accelerated to a speed of (5.60x10^5) m/s?
Wednesday, October 29, 2014 by Joey

Chemistry
Silver carbonate [AgCar] has a density of 6.077 g/cm3. Calculate the mass (in fg) of carbon atoms [C] present in a AgCar crystal that has a volume of 457.6 Å3.
Tuesday, October 28, 2014 by Sydney

Chemistry
If a sample of ammonium sulfate contains 1.75 grams of nitrogen [N] atoms, calculate the mass (in grams) it contains of sulfur atoms [S].
Tuesday, October 28, 2014 by Amanda

Chemistry
If you used 2.0mL of 1.0M H2SO4 and 3.0g of NaHCO3 how many moles of CO2 would be produced?
Tuesday, October 28, 2014 by EFonts

Chemistry
When you have 50ml of a 0.25M solution of KI in water. What should the final volume be is you want to reduce the concentration to .10M
Tuesday, October 28, 2014 by EFonts

Chemistry
Hello. On the homework for my middle school chemistry class, one of the questions asks me to identify "the four classifications of substances". I am having difficulties with this problem.
Tuesday, October 28, 2014 by Max

Chemistry
The combustion of octane produces carbon dioxide and water. If you start with 10.0 mol of octane, what mass of water (in grams) would you expect to produce?
Tuesday, October 28, 2014 by Hazel

chemistry
1. A gas cylinder contains 0.722 mL of hydrogen gas at a pressure of 10.6 atm. If the gas is used to fill a balloon at a pressure of 0.960 atm, what is the volume of the filled balloon?
Tuesday, October 28, 2014 by Megan

chemistry
Why is it important to make sure that the volume of water and the starting temperature are the same in each trial ?
Tuesday, October 28, 2014 by danny

Chemistry
need the answers to the formulas for the Ionic Compound: DiAmmonium Chromate Also I need the name of the following formula Sr(MnO4)2
Tuesday, October 28, 2014 by Theresa

Chemistry
How many atoms of aluminum [Al] are present in a sample of aluminum carbonate [AlCar] weighing 3.45E6 amu?
Tuesday, October 28, 2014 by Amanda

chemistry
Calculate the volume of concentrated NaOH solution (which contains 500.00g of NaOH per liter of solution) that you will need to make 1.00L of a 0.100M NaOH solution
Tuesday, October 28, 2014 by xx

chemistry
Calculate the mass of KHP which will result in an endpoint of 20.00mL when titrated against 0.097M NaOH
Tuesday, October 28, 2014 by xx

chemistry
Calculate the volume of 0.102M NaOH necessary to react with 22.00mL of 0.10M HCl.
Tuesday, October 28, 2014 by xx

Chemistry
the solubility of aluminum sulfate in water at 20 degrees celcius is 26.7 g/100mL Calculate the molarity?
Tuesday, October 28, 2014 by Gina

chemistry
A titration of 15.75mL HCL of an unknown molarity requires 20.35mL of 0.0903M NaOH solution. What is the molarity of the HCl solution?
Tuesday, October 28, 2014 by xx

chemistry
A student adds 25.00mL of distilled water to a 10.00mL sample of HCl of an unknown molarity and titrates this against a 0.085M NaOH solution. Will the addition of the water interfere with the determination of the molarity of the HCl sample? Why or why not?
Tuesday, October 28, 2014 by xx

Chemistry
Calculate the molarity of the HCl solution if 25.00ml of the acid are required to neutralize 1.00g of each of the following 1) KOH 2)Ca(OH)2 I calculated the molar mass of KOH which was 56.11 Then I took 1.00g/56.11 = 0.0178mol To find out the molarity I did 0.0178/0.025=0....
Tuesday, October 28, 2014 by Sarah

Chemistry
What are the products for KMnO4 + FeSO4 + NaOH? What is the net ionic equation? I am pretty sure one of the products in MnO2, because I got a muddy brown parcipitate, but I've been getting a variety of answers.
Tuesday, October 28, 2014 by Sarah

Chemistry
The density of ethanol is 0.789g/cm3 at 20 degreesC. What volume of ethanol has a mass of 15.5 grams?
Tuesday, October 28, 2014 by tmccloud

chemistry
When a 3.10g sample of liquid octane (C8H18) is burned in a bomb calorimeter, the temperature of the calorimeter rises by 26.8∘C. The heat capacity of the calorimeter, measured in a separate experiment, is 6.30kJ/∘C . Determine ΔErxn for the combustion of ...
Tuesday, October 28, 2014 by annoymous

chemistry
A ballon is filled with 54.8 g of CO2. The gas is at STP. Calculate the volume of the CO2 gas in liters?
Tuesday, October 28, 2014 by Widener

Chemistry
Q1. A 0.5 g mixture of Cu2O and CuO contain 0.425 g Cu. What is the mass of CuO in the mixture? Q2. A chemist wants to prepare 0.5 M HCl. The label of a commercial hydrochloric acid shows that S.G. =1.18 and concentration of HCl was 37%. Calculate the volume of commercial ...
Tuesday, October 28, 2014 by Adem Rutger

Chemistry
The reaction of iron and water vapor results in an equilibrium reaction, 3 Fe(s) + 4 H2O(g) ¡ê Fe3O4(s) + 4 H2(g) and an equilibrium constant of 4.6 at 850¡ÆC. What is the concentration of Hydrogen present at equilibrium if the reaction is initiated ...
Tuesday, October 28, 2014 by David

AP Chemistry
if the energy to break bonds is greater than the energy to form the bonds, is it exothermic?
Tuesday, October 28, 2014 by Sara

  1. Pages:
  2. <<Prev
  3. 33
  4. 34
  5. 35
  6. 36
  7. 37
  8. 38
  9. 39
  10. 40
  11. 41
  12. 42
  13. 43
  14. 44
  15. 45
  16. 46
  17. 47
  18. Next>>

Homework Help: Science

Members