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May 4, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Compute the number of molecules of water driven off when 12.05g of sodium acetate trihydrate is heated.
Saturday, December 12, 2015 by Anon

Chemistry
Suppose we had mixed 52.37 mL of 1.00 M HI solution with 25.42 mL of 1.00 M KOH solution, and measured a heat of reaction of -1.52 kJ. What is ΔH for this reaction, in kJ? Assume that all solutions have the same density as water (1.00 g/mL).
Friday, December 11, 2015 by Will

Chemistry
At its normal boiling point of 126°C n-octane, C8H18, has a vapor pressure of 760 torr. What is its vapor pressure at 25°C? the enthalpy of vaporization of n-octane is 39.07 kj/mol.
Friday, December 11, 2015 by Nicole

Chemistry
Rank the following in order of increasing vapor pressure at 298 k: CH3CH2OH, CH3OCH3, CH3CH2CH3.
Friday, December 11, 2015 by Nicole

Chemistry
how many milliliters of a 2.61 m h2so4 solution are needed to neutralize 71.50 ml of a 0.855 m koh solution
Friday, December 11, 2015 by Patty

Chemistry
how many milliliters of a 2.61 m h2so4 solution are needed to neutralize 71.50 ml of a 0.855 m koh solution
Friday, December 11, 2015 by Anonymous

Chemistry
If you reacted 100.0 g of carbon tetrachloride (CCl4) with excess antimony fluoride (SbF3), how many grams of carbon dichloride difluoride would be produced?
Friday, December 11, 2015 by Catherine

Chemistry 12
The molar heat of vaporization of water is 42 kJ/mol. How much energy is released by the condensation of 3.0 g of water? So for water there will just be one mol. I think this is how you do it, but it doesn't match the answer in the worksheet. q=mc delta t But we're not...
Thursday, December 10, 2015 by Rachel

Chemistry
please balance this chemical equation iron +oxygen > iron (III) oxide +energy Fe + O2> Fe2 O3 + heat and light
Thursday, December 10, 2015 by Donald

Chemistry
is delta S positive for the heating of water from 25 to 75 degrees Celsius?
Thursday, December 10, 2015 by john

Chemistry
How can i synthensize 1g of salicylic acid from Phenol
Thursday, December 10, 2015 by Adeola

Chemistry
How can i synthensize 1g of salicylic acid from benzene
Thursday, December 10, 2015 by Adeola

General Science/ Chemistry
Is it necessary to know the exact volume of the “unknown” acid or base to be titrates.
Thursday, December 10, 2015 by Mark

Chemistry
Why do the alkali metals have low ionization energies but relatively large atomic size? (I thought larger atomic sizes meant higher ionization energies.) What is the relationship between the two?
Thursday, December 10, 2015 by Anonymous

Chemistry
If a basic solution has a pH of 11.88, is it considered to be a strong base? Is an acidic solution with a pH of 4.44 considered to be a strong acid?
Thursday, December 10, 2015 by Jessica

chemistry
A reagent bottle contains 5.00g of NaOH.how many milliliters of a 2.00M silution can be prepared from this weight of NaOH?
Thursday, December 10, 2015 by Anonymous

Chemistry
A 100.0-mL sample of air is collected at 21 degrees Celsius and 772 mm Hg. What is the volume of air at STP? I know that I have to change deg. Celsius to K and mm Hg to atm. I'm stuck on what formula I should use... Should I use PV=nRT?
Thursday, December 10, 2015 by Jason

chemistry
How many Lithium ions are in 75.3 grams of lithium sulfate?
Thursday, December 10, 2015 by Anonymous

Chemistry
My question is: What is the mass of solute in a 25.0 g of 10.0 %(m/v) sucrose solution? (Assume density of solution is 1.15 g/mL) I was wondering if my answer: 2.17 g solute is correct? Thank you
Wednesday, December 9, 2015 by Cece

Chemistry 12
"Add the ionic equations for part one and three, compare the results with the ionic equation for part two" Part 1: NaOH(s) = Na+(aq) +OH-(aq) + heat Part 2: NaOH(s) + H+(aq) +Cl-(aq) = Na+(aq) + Cl-(aq) + H2O(l) + heat Part 3: Na+(aq) + OH-(aq) + H+(aq) + Cl-(aq) = ...
Wednesday, December 9, 2015 by Avery

Chemistry
What mass of lead (II) sulphate would be produced by the action of excess dilute sulpuric acid on 10 g of lead nitrate dissolved in water? I need help, at least an example.
Wednesday, December 9, 2015 by Jaevon

Chemistry
A solution containing 22.18 mL of a .1212 M H2CO3 solution is mixed with 17.22 mL of a .1234 M Na2CO3 solution. What is the pH of the final mixture? Ka1 = 6.2x10-7 Ka2 = 4.4x10-11. If you diluted the mixture up to 100 mL, would the pH change? If it does change, what would the ...
Wednesday, December 9, 2015 by Jill

Chemistry
Citric acid is a tri-protic acid with a Ka1 =8.4x10-4 Ka2=1.8x10-5 and Ka3=4.0x10-6. calculate the pH at the 2nd equivalence point in the titration of 85.5 mL of a .21 M citric acid solution with .25 M NaOH. Calculate the pH, after 25.8 mL of NaOH have been added. Calculate ...
Wednesday, December 9, 2015 by Jill

Chemistry
a 5.000ml aqueous sample containing hydrogen peroxide as diluted to 25ml and analyzed by titration with permanganate. 2MnO4- + 5H2O + 6H+ --> 5O2 + 2Mn^2+ + 8H2O The sample required 42.8 mL of 0.0175 M permangante to reach the end point. What is the concentration of H2O2 in...
Wednesday, December 9, 2015 by Sarah

Chemistry
Alloys of copper and zinc are used to produce brass. Why do these elements not react in this application?
Wednesday, December 9, 2015 by Tom

Chemistry
Calcuate the tatla volme of gas (at 45c and 785mmHg) producedbby the complete decmpotition of 2.55kg of ammoniium nitrate.
Wednesday, December 9, 2015 by Teisha

Chemistry
A sample of nitrogen gas was collected via water displacement. Since the nitrogen was collected via water displacement, the sample is saturated with water vapor. If the total pressure of the mixture at 21 °C is 1.16 atm, what is the partial pressure of nitrogen? The vapor ...
Wednesday, December 9, 2015 by Leanna

Chemistry
A sample of nitrogen gas was collected via water displacement. Since the nitrogen was collected via water displacement, the sample is saturated with water vapor. If the total pressure of the mixture at 21 °C is 1.16 atm, what is the partial pressure of nitrogen? The vapor ...
Wednesday, December 9, 2015 by Leanna

Chemistry
I have to list distributed benzene in order of polarity, and I don't think i know how to do that, but does polarity have to do with dipole moments?
Wednesday, December 9, 2015 by Dan

Chemistry
I just need someone to check over my answers, I'm pretty confident in all of them! In which six-membered hydrocarbon rings are all of the C-C-C angles roughly the same, i.e., within 1o? Select ALL that apply. Question 1 options: A)cyclohexane B)cyclohexene C)1,3-...
Wednesday, December 9, 2015 by Dan

chemistry
C2H6 <> C2H4 + H2. when 1.00mol ethane is cracked at 180kPa and 1000K, the yield of ethene is 0.36mol. Calculate the value Kp at 1000K...
Wednesday, December 9, 2015 by jay

Chemistry (Help)
I'm having trouble figuring out this one. Can you please help? I haven't gotten a response to any of my questions. Chemical formula: Na Name: Sodium Bond Type (intramolecular FOA): metallic bond VSEPR molecular shape: none Central Atom Hybridization: none? Molecular ...
Wednesday, December 9, 2015 by Kyle

Chemistry (Check)
Are these right? Chemical formula: NaCl Name: Sodium chloride Bond Type (intramolecular FOA): ionic bonding VSEPR molecular shape: none Central Atom Hybridization: sp3 Molecular Polarity: polar Interparticle force of attraction (IPFOA): London, dipole-dipole, ion-dipole State ...
Wednesday, December 9, 2015 by Kyle

Chemistry
Explain the trends in the solubility of water.
Wednesday, December 9, 2015 by Anonymous

Chemistry
Did u think about it?
Wednesday, December 9, 2015 by Scott

Chemistry
Draw the best Lewis structures for NO+, NO2-, NO2H, and NO3-. Based on the Lewis structures, list all of the the N-O bonds lengths in order of shortest (1) to longest (5). N-O bond length in >>> 2 N-O double bond in NO2H >>> 1 N-O bond length in NO3- >>...
Tuesday, December 8, 2015 by Dan

Chemistry. Half Life Problem. Help Plz
If the half-life of iodine-131 is 8 day, how much would remain undecayed after 8 day if we started with 38 grams? How much at 16 days? 24 days? 32 days?
Tuesday, December 8, 2015 by Dominick

Chemistry
The number of protons in a cation must always be ________ the number of electrons.
Tuesday, December 8, 2015 by Dominick

Chemistry. I got the wrong answer. Plz help
A sample of sodium reacts completely with 142 g of chlorine, forming 234 g of sodium chloride. What mass of sodium reacted? I took 142g of Cl / 35.5g/mol = 4 mols of Cl Then I took 58.44g/mol x 4 mols of Cl = 233.76 It asked for three significant figures only so I put 233 and ...
Tuesday, December 8, 2015 by Dominick

Chemistry. Plz Help!
A sample of sodium reacts completely with 142 g of chlorine, forming 234 g of sodium chloride. What mass of sodium reacted? Express your answer to three significant figures and include the appropriate units.
Tuesday, December 8, 2015 by Dominick

Chemistry. Plz Help!
When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 20.4 g of carbon were burned in the presence of 71.1 g of oxygen, 16.7 g of oxygen remained unreacted. What mass of carbon dioxide was produced? Express your answer to three significant figures ...
Tuesday, December 8, 2015 by Dominick

Chemistry
Sodium chloride dissolves in water (solubility in water is 361g/1L), but copper (II) phosphate does not dissolve in water (insoluble). A. Describe in a stepwise fashion how the solid sodium chloride dissolves in the water to form a solution. (name the resulting interparticle ...
Tuesday, December 8, 2015 by Anonymous

Chemistry
When carbon is burned in air, it reacts with oxygen to form carbon dioxide. When 20.4 g of carbon were burned in the presence of 71.1 g of oxygen, 16.7 g of oxygen remained unreacted. What mass of carbon dioxide was produced? Express your answer to three significant figures ...
Tuesday, December 8, 2015 by Dominick

Chemistry
A sample of sodium reacts completely with 142 g of chlorine, forming 234 g of sodium chloride. What mass of sodium reacted?
Tuesday, December 8, 2015 by Dominick

Chemistry
Chemical formula: NaCl Name: Sodium chloride Bond Type (intermolecular FOA): London, dipole-dipole, ion-dipole VSEPR molecular shape: none Central Atom Hybridization: sp3 Molecular Polarity: polar Interparticle force of attraction (IPFOA): ? State of Matter (at room ...
Tuesday, December 8, 2015 by Anonymous

Chemistry
Explain trends in the solubility of water (amount of the compound (solute) that will dissolve in a given amount of solvent (water).
Tuesday, December 8, 2015 by Anonymous

Chemistry Help
Which of the following exhibits the highest boiling point? HF, HCl, HBr, or HI Which of the following exhibits the highest boiling point? CH3CH3, CH3COOH, or CH3OCH3 How can you determine the highest boiling point of these?
Tuesday, December 8, 2015 by Kyle

Chemistry
Chemical formula: Na Name: Sodium Bond Type (intermolecular FOA): London VSEPR molecular shape: none Central Atom Hybridization: sp Molecular Polarity: nonpolar Interparticle force of attraction (IPFOA): ? State of Matter (at room temperature): solid Can't figure out the ...
Tuesday, December 8, 2015 by Anonymous

Chemistry
Which of the following exhibits the highest boiling point? Ne, Ar, Kr, or Xe My answer: Xe Which of the following exhibits the highest boiling point? F2, Cl2, Br2, or I2 My answer: HI Which of the following exhibits the highest boiling point? NaCl, SO2, or N2 My answer: SO2 ...
Tuesday, December 8, 2015 by Kyle

Chemistry
Can you please check if these are right? I'm not sure about IPFOA. Chemical formula: H2O Name: Dihydrogen oxide Bond Type (intermolecular FOA): London, dipole-dipole, hydrogen bonding VSEPR molecular shape: bent Central Atom Hybridization: sp3 Molecular Polarity: polar ...
Tuesday, December 8, 2015 by Anonymous

Chemistry
Is it true that the higher the boing point, the higher the vapor pressure?
Tuesday, December 8, 2015 by Sarah

Chemistry
How do you solve for enthalpy of vaporization? I know it's liquid to gas, but I can't figure out how to solve an actual problem like C2H4O2. Could you please explain?
Tuesday, December 8, 2015 by Anonymous

Chemistry
How much total work does a golf caddy do if he lifts a 300 N golf bag he is carrying 100 times a during a round, to a height of 1.0 m each time he lifts it?
Tuesday, December 8, 2015 by Kaitlyn

Chemistry
Rank the following in order of decreasing vapor pressure, and briefly explain the observed trend in vapor pressure: Acetic Acid Isobutane Acetamide Propanal
Tuesday, December 8, 2015 by Sarah

Chemistry
Hey can you please check my answers? Also, Can you explain interparticle force of attraction? I'm not sure about the difference between IMFOA and IPFOA. Chemical formula: Cl2 Name: Chlorine Bond Type (intermolecular FOA): London VSEPR molecular shape: tetrahedral Central ...
Tuesday, December 8, 2015 by Anonymous

Chemistry
Fe2O3 + Fe + H2SO4 → FeSO4 + H2O How would I balance this using oxidation numbers? Is the Fe2 being reduced and the Fe being oxidized?
Tuesday, December 8, 2015 by Luke

applied chemistry
Draw electron dot diagram for the following compound HCL,CO2,NH3,NH4CL,CH4 And H2O2
Tuesday, December 8, 2015 by francis

chemistry physics
Which following assertions are true ? - unanswered 13C NMR is more sensitive than 1H NMR because of the 1.1% natural abundance of 13C nuclei. 13C nuclei have a ½ spin and can be detected in NMR, opposite to more abundant 12C nuclei. 13C NMR requires a different ...
Tuesday, December 8, 2015 by Abd

Chemistry
Give two physical properties of ionic compounds? Thanks.
Tuesday, December 8, 2015 by Isha

Chemistry
Hey can you please check my answers? Also, Can you explain interparticle force of attraction? I'm not sure about the difference between IMFOA and IPFOA. Chemical formula: Cl2 Name: Chlorine Bond Type (intermolecular FOA): London VSEPR molecular shape: tetrahedral Central ...
Monday, December 7, 2015 by Anonymous

Chemistry
Would copper (II) phosphate be nonpolar?
Monday, December 7, 2015 by Sarah

Chemistry
Identify the predominant intermolecular force in each of these substances. 1. Hydrogen 2. Dipole-Dipole 3. London A)H20 B)NH3 C)CH3 C=O OCH3 D)CH4 E)CH OH-C-OH CH3 what I have so far is A) 1 B) 1 C) 2 D) 3 E) I'm not sure about E, I think it might be dispersion?
Monday, December 7, 2015 by Dan

Chemistry
Calculate the molecular weight of a gas if 16.8 g of the gas occupies 16.3 L at STP.
Monday, December 7, 2015 by Shawn

chemistry
How do you write the balanced chemical equation for the addition of aqueous potassium fluoride to aqueous copper(II) sulfate? please explain this as a step by step process.
Monday, December 7, 2015 by amellusrosa

Chemistry
An excited ozone molecule, O3*, in the atmosphere can undergo one of the following reactions, O3* → O3 (1) fluorescence O3* → O + O2 (2) decomposition O3* + M → O3 + M (3)deactivation, where M is an inert molecule, the rate constant for the fluorescence ...
Monday, December 7, 2015 by Anonymous

Chemistry
A mass of aluminium metal is heated in a such in a such a way that is was exposed to air.(1.751g Al) A compound containing aluminium and oxygen is formed. It has a mass of 3.311 g. What is the empirical formula of aluminum oxide according to this experimental data?
Monday, December 7, 2015 by Jessie

Chemistry
How many grams of O2 are released into the environment during the production of the 5.1 grams of glucose?
Monday, December 7, 2015 by Vinny

AP Chemistry
Calculate ΔHrxn for the following reaction: C(s)+H2O(g)→CO(g)+H2(g) Use the following reactions and given ΔH values: C(s)+O2(g)→CO2(g), ΔH= -393.5 kJ 2CO(g)+O2(g)→2CO2(g), ΔH= -566.0 kJ 2H2(g)+O2(g)→2H2O(g), ΔH= -483.6 kJ
Monday, December 7, 2015 by Q

chemistry
how many oxygen atoms are in 10 formula of Al2(SO4)3
Monday, December 7, 2015 by patricia

Chemistry
3. Choose the hybridization schemes for the following species. (a) AsBr6− sp sp2 sp3 sp3d sp3d2 (b) CSe2 sp sp2 sp3 sp3d sp3d2 (c) PbCl4 sp sp2 sp3 sp3d sp3d2 (d) SeO32− sp sp3 sp2 sp3d sp3d2 (e) BiF5 sp sp2 sp3 sp3d sp3d2
Monday, December 7, 2015 by S

Chemistry
2. Which of the following molecules is/are trigonal pyramidal? N2O NH3 C2H2 SiF4 HN3 HCN SO3 H2S CF4 PF3 H2O BF3 COS O3 SO2 CS2 AsH3
Monday, December 7, 2015 by S

Chemistry
1. [ PF4 ]+ (a) What is the electron-group geometry, according to VSEPR theory? (b) What is the molecular geometry? (c) Is this species polar or nonpolar?
Monday, December 7, 2015 by S

chemistry
Determine the final temperature of a 10 gram aluminum block originally at 25.0 degrees Celsius if you apply 435 J of energy to it.
Monday, December 7, 2015 by Jenifer

Chemistry
Compute the surface area of revolution about the x-axis over the interval. y = x^2, [0, 4] Is it (pi/12)(65^2 - 65)^(3/2)?
Monday, December 7, 2015 by Sanaya

Chemistry
Zn + 2HCl = ZnCl2 + H2 Which amount would produce more H2: 17gramsZn OR 150 mL of 0.5HCl?
Monday, December 7, 2015 by Ashley

CHEMISTRY
A quantity of N2 occupies a volume of 1.5 L at 300 K and 1.2 atm . The gas expands to a volume of 3.2 L as the result of a change in both temperature and pressure.
Monday, December 7, 2015 by Anonymous

Chemistry-Dr.Bob
What is the increasing dipole moment for CO,CS, and SiS? My answer: SiS<CO<CS Is this correct?
Monday, December 7, 2015 by Sanaya

chemistry
how many electrons are transfered in one atom of Mn in the reaction?MnO2+4HCl=MnCl2+2H2O+Cl2
Monday, December 7, 2015 by Natty

chemistry
A sample consist only NaCl and NaBr has amass of 0.7648gm. This sample is place in solution in which excess of silver is added which forma precipitate the AgCl and AgBr has amass of 1.5758 gm . what's the percentage of Cl and Br in original sample ?
Monday, December 7, 2015 by Nechirwan

Chemistry
How can you tell if a compound is polar or nonpolar? Is it just by lewis structures? what would copper (II) phosphate be?
Monday, December 7, 2015 by Sarah

chemistry
ΔH°rxn is -114.14 kJ/mol. Calculate ΔH°f of gaseous nitrogen monoxide, given that ΔH°f of NO2(g) is 33.90 kJ/mol.
Monday, December 7, 2015 by lee

Chemistry
When given different elements and asked for the highest boiling point, do you figure out the molar mass and pick the highest one as the highest boiling point?
Monday, December 7, 2015 by Sarah

Chemistry
A pot containing 500 g of water at 100 degrees Celsius would require how much energy to boil off completely
Monday, December 7, 2015 by Erika

chemistry
Calculate the molarity of a 6% solution of ammoniun nitrate of density 1.025 g/mL
Monday, December 7, 2015 by derek

Chemistry
Sodium chloride dissolves in water (solubility in water is 361g/1L), but copper (II) phosphate does not dissolve in water (insoluble). A. Describe in a stepwise fashion how the solid sodium chloride dissolves in the water to form a solution. (name the resulting interparticle ...
Sunday, December 6, 2015 by Anonymous

chemistry
a gas has a volume of 95 mL at a pressure of 930 torr. What volume will the gas occupy if the pressure is increased to 970 torr and the temperature remains constant
Sunday, December 6, 2015 by viridiana

Chemistry
34.09 ml of 0.251 M KOH is required to tritate a 10.2951 g sample of acetic acid solution. The density of the solution had been previously found to be 1.007g/ml. what is the molarity of the aetic acid solution?.
Sunday, December 6, 2015 by sandra

Chemistry
Can pi bonds be made from d-orbitals?
Sunday, December 6, 2015 by Sanaya

chemistry
How to solve this problem in counting atoms 2 pb(CN)2
Sunday, December 6, 2015 by bob

Chemistry
How many grams of cesium chloride (CsCl) will be needed to make 750. mL of a 0.100 M CsCl aqueous solution? The formula mass of CsCl is 168.36 g/mol. Remember Molarity: M = (mol solute) / (L of solution) I need help solving this problem
Sunday, December 6, 2015 by Mark

Chemistry
A compound that you are studying is soluble in CCl4 but not in water. Would you predict that the compound is polar or nonpolar? Why? [Please explain; don’t just give a trivial answer such as “Because like dissolves like”.]
Sunday, December 6, 2015 by Mark

Chemistry
150 g of water at 80 degree Celsius is cooled to 50 degree Celsius how much heat is lost bye the water
Sunday, December 6, 2015 by Kelly

Chemistry
Chart: Group, Bond length, Bond strength, H-X-H Bond Angle NH3: 1.000, 391, 107 PH3: 1.412, 322, 93.5 AsH3: 1.510, 247, 92 SbH3: 1.688, 247, 92 What physical states do these molecules exist at room temperature? Gas Briefly explain the observed trend in bond length. Briefly ...
Sunday, December 6, 2015 by Anonymous

Chemistry (Check)
Which of the following exhibits the highest boiling point? a. Ne, Ar, Kr, or Xe? Xe b. HF, HCl, HBr, or HI? HI c. CH3CH3, CH3COOH, or CH3OCH3? CH3COOH d. F2, Cl2, Br2, or I2? I2 e. NaCl, SO2, or N2? SO2 Are these right? I just went by molar mass. If these are wrong, please ...
Sunday, December 6, 2015 by Anonymous

chemistry
Consider the following equation: CO + 2 H2 → CH3OH △H rxn = -128 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 8.08 g H2
Sunday, December 6, 2015 by katia

chemistry
Consider the following reaction: 2 Mg + O2 → 2 MgO △H rxn = -1203 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 4 moles of Mg.
Sunday, December 6, 2015 by katia

Chemistry (Check and Help)
Hey can you please check my answers? Also, Can you explain interparticle force of attraction? I'm not sure about the difference between IMFOA and IPFOA. Chemical formula: Cl2 Name: Chlorine Bond Type (intermolecular FOA): London VSEPR molecular shape: tetrahedral Central ...
Sunday, December 6, 2015 by Anonymous

chemistry
Help me solve it. Step by step please The value of kp at 20°c for the reaction 2NO(g) +Cl2(g) 2NOCl(g) is 1.9x10^3 atm-1 calculate the value of KC at the same temperature.
Sunday, December 6, 2015 by john

chemistry
how many joules are needed to completely melt 25 grams of ice at 0 degree celcius?
Sunday, December 6, 2015 by b

chemistry
0.5g of an organic compound x (containing carbon hydrogen oxygen) produces 0.733g of carbondioxide and 0.3g of water on complete combustion.the max spectrum shows mr=60.determine molecular formula of x
Sunday, December 6, 2015 by ali

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Homework Help: Science