Monday
December 5, 2016

# Posts by Chemistry

Total # Posts: 240

Science
I don't know what to do with it but the problem is that I can do it.
November 24, 2016

Science
Calculate the gram molecular mass of nitrogen if 360cc at STP weigh 0.45g.
November 24, 2016

Chemistry
Re crystallization of Brass. we did the Rockwell Hardness test on a metal sample and then we took the metal sample to be seen under a microscope to see if there were any crystal twinning. This is why we etched the metal but I can not understand why we etched it.
October 17, 2016

Chemistry
Why was etching needed to bring out the grain boundaries? My answer: Is it for the light to bounce back?
October 17, 2016

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

Kris
April 3, 2016

Kris
A gas mixture containing 0.400 mol He, 0.184 mol CH4 and 0.0374 mol Ne was placed in a 3.00-L flask at 301 K. What is the PRESSURE (atm) in the flask?
April 3, 2016

HOFBrINCl
can someone help me on these 2 questions so i can get an idea to do the rest of mine. im given hydrochloric acid and a marble chip (calcium carbonate i think), so what would be the reactants, the word equation, the balanced equation, prediction of type of reaction for this? ...
March 15, 2016

May
That table looks a little wonky! I hope this looks a little better: T ....... k 625 ..... 1.1 x 10^-4 635 ..... 1.5 x 10^-4 645 ..... 2.0 x 10^-4
February 1, 2016

May
Based on the data in this table, what would be the value of k at 795 K? T k 625 1.1 x 10^-4 635 1.5 x 10^-4 645 2.0 x 10^-4 I tried to figure it out using two different ways, and I got 7.3 x 10^-3 both times. I asked for a "hint" and the homework site told me to ...
February 1, 2016

for solubility
How match water make in 0.123 N NaoH for 0.1 N NaoH
January 24, 2016

georgia
what is a solubility rate?
August 26, 2015

Chemistry
CH4 is the limiting reactant
May 19, 2015

caley
A solution contains 2.0 × 10^–3 M Ba^2+ and 1.0 × 10^–2 M Sc^3+. A source of F^– is slowly added to the solution. Will BaF2 (Ksp = 1.84 × 10^–7) or ScF3 (Ksp = 5.81 × 10^–24) precipitate first? I believe that ScF3 would ...
May 19, 2015

math
A. 8.75a + 6.5c + 6.5s = total cost. B. 8.75(2) + 6.5(3) + 6.5(4) = answer C. 8.75(4) + 6.5(2) = answer Just compare the totals to see if they are the same
May 19, 2015

Equilibrium constant
Consider the reaction: SO2Cl2(g)⇌SO2(g)+Cl2(g) A solution is made containing initial [SO2Cl2]= 0.022M . At equilibrium, [Cl2]= 1.7×10−2M Calculate the value of the equilibrium constant.
May 5, 2015

Equilibrium
An equilibrium mixture of the following reaction was found to have [I2]= 0.0325M at 1200 ∘C. What is the concentration of I ? I2(g)⇌2I(g) Keq= 1.5×10−2 at 1200 ∘C Someone please help set this up?
May 5, 2015

Volume
Imagine that you have an ideal gas in a 7.00L container, and that 1050 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 ...
April 30, 2015

Molar mass
A sample of gas has a mass of 0.580g . Its volume is 119mL at a temperature of 80∘C and a pressure of 743mmHg . Find the molar mass of the gas. I think I got a step wrong in the problem, please help?
April 29, 2015

pressure
What is the pressure in millimeters of mercury of 0.0140mol of helium gas with a volume of 222mL at a temperature of 30∘C?
April 29, 2015

Pressure
Aerosol cans carry clear warnings against incineration because of the high pressures that can develop upon heating. Suppose a can contains a residual amount of gas at a pressure of 750mmHg and a temperature of 23∘C. What would the pressure be if the can were heated to ...
April 29, 2015

Freezing point
How many moles of each of the following are needed to give the same freezing point lowering as 5.0mol of the nonelectrolyte ethylene glycol in 1 kg of water?CH3−OH, a non electrolyte, KNO3, a strong electrolyte. Im confused on what they are asking, and how in the world ...
April 28, 2015

Moles
How many moles of each of the following are needed to give the same freezing point lowering as 5.0mol of the nonelectrolyte ethylene glycol in 1 kg of waterCH3−OH, a non electrolyte,KNO3, a strong electrolyte I am so lost with what they exactly want for this?
April 27, 2015

Freezing solution
Calculate the boiling point of the solution. whats you do for the next step then
April 27, 2015

Freezing solution
An ethylene glycol solution contains 26.2g of ethylene glycol (C2H6O2) in 81.4mL of water. Calculate the freezing point of the solution. (Assume a density of 1.00 g/mL for water.) how do I set this up?
April 27, 2015

mass
A hard water sample contains 0.0081 %Ca by mass (in the form of Ca2+ ions)What mass of water in grams contains 1.3g of Ca? (1.3g of Ca is the recommended daily allowance of calcium for 19- to 24-year-olds.) Need help set this up?
April 19, 2015

Molarity
A 44.8−mL sample of a 7.0M KNO3 solution is diluted to 1.10L What volume of the diluted solution contains 16.0g of KNO3? Would I do the same thing for this one or would does it have an extra step it it.
April 19, 2015

Metals
Transition metals (also called heavy metals) form insoluble compounds with hydroxide ions. Therefore, it is possible to extract heavy metal ions from water by raising the pH. The precipitation reaction between cadmium(II) and hydroxide is shown below. Cd2+(aq) + 2OH−(aq...
April 19, 2015

Molarity
A 44.8−mL sample of a 7.0M KNO3 solution is diluted to 1.10L What volume of the diluted solution contains 16.0g of KNO3? Would I do the same thing for this one or would does it have an extra step it it.
April 19, 2015

Molarity
A 4.0−L sample of a 6.3M NaCl solution is diluted to 50L . What is the molarity of the diluted solution? How would I set this up?
April 19, 2015

Heat
Thank you I guess i forgot to convert
April 18, 2015

Heat
Consider the following equation: CO + 2 H2 → CH3OH ΔH rxn = -128 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 8.08 g H2. How would u set that up?
April 18, 2015

Enthalpy
Consider the following reaction: 2 Mg + O2 → 2 MgO ΔH rxn = -1203 kJ Calculate the amount of heat (in kJ) associated with complete reaction of 4 moles of Mg. How do I set this up correctly?
April 18, 2015

Chemical Reactions
How can i get the step by step procedure for a chemical reaction? For example: the step by step procedure for the synthesis reaction of ammonia
April 12, 2015

Chemistry
So would i multiply 4.86 x 10^23 by 7 to get the number of carbon atoms And multiply by 8 to get the number of hydrogen atoms
November 24, 2014

Chemistry
A sample of toluene, C7H8 has a mass of 74.5 g. a) how many molecules does the sample contain? b) How many carbon atoms does it contain? How many hydrogen atoms does it contain? My work For b would it be 7 carbon atoms and 8 hydrogen atoms
November 24, 2014

newsome
1. lactate has a molecular weight of 90.08. How much lactate is needed to make 3 liters of .15 molar lactate. 2.What is the percentage of lactate (it's a solid) in the solution made in question 1.
November 13, 2014

1. Spectroscopic studies of the reaction of azide ion with the cluster [Ru3(CO)12] in acetone solvent confirmed the occurrence of process (i) under a CO atmosphere. Kinetic measurements of this rapid [Ru3(CO)12]+ N3– →[Ru3(NCO)(CO)11]–+ N2(i) reaction revealed ...
July 25, 2014

Chemistry
Calculate the volume of 2.00 M solution of KOH that is required to neutralize 30.0 mL of 1.00 M solution of HNO3.
May 6, 2014

chemistry
Find the Qsp when 5 mL of 0.17 M K2 CO3 (aq) and 1 L of 0.013 M AgNO3(aq) are mixed together. The solubility product of Ag2CO3 is 6.2 × 10−12
April 21, 2014

CHEMISTRY
Method for getting correct answer? Thank you! Initially there were equilibrium concentrations of 0.1887 M A, 0.1042 M B. Which of the equations below is correct if the pressure decreased by a factor of 2.40? Use the reaction below. 6A(g) ↔ 5 B(g) a. Qc = 0.42 Kc b. Qc = ...
April 6, 2014

CHEMISTRY
Thank you for the help!
April 6, 2014

CHEMISTRY
Method for getting correct answer? Thank you! The reaction below is an endothermic reaction. What would one have to do to shift the equilibrium to the right? SO2Cl2(g)↔SO2(g) + Cl2(g) a. Decrease the temperature b. Increase the temperature c. Remove some reactant d. An ...
April 6, 2014

CHEMISTRY
Thank you! .434^5 / .0786^6 equals .653, that is correct! I was just able to answer another problem similar to this thanks to your help. Many thanks!
April 6, 2014

CHEMISTRY
Method for getting correct answer? Thank you! Initially there were equilibrium concentrations of 0.1887 M A, 0.1042 M B. Which of the equations below is correct if the pressure decreased by a factor of 2.40? Use the reaction below. 6A(g) ↔ 5 B(g) Qc = 0.42 Kc Qc = 0.45 ...
April 6, 2014

CHEMISTRY
Method for getting correct answer? Thank You! What is Kp for the reaction below, if Kc = 1.13e-3 at 111.2°C? 4A(s) + 5B(g) ↔ 3C(g) a. 1.36e-5 b. 1.15e-12 c. 1.14e-6 d. 8.42e-3
April 6, 2014

CHEMISTRY
Method for how to get answer? Thank you! For the equilibrium reaction below. To what is Kc equal? N2(g) + 3H2(g) ↔ 2NH3(g) a. [N2] + 3[H2] ------------------ 2[NH3] b. [N2][H2]3 ------------------ [NH3]2 c. 2[NH3] --------------- [N2]+ 3[H2] d. [NH3]2 --------------- [N2...
April 6, 2014

CHEMISTRY
Method for getting correct answer? Thank you! What is the value of Kc at 226.85 °C for the reaction below if Kp is 6.24e-3 at this temperature? CO(g) + 2H2(g) ↔ CH3OH(g) a. 3.70e-6 b. 2.1614 c. 1.08e5 d. 10.5000
April 6, 2014

CHEMISTRY
Method for getting correct answer for this? Thank you! For the reaction A ↔ 2B K = 3.80x10-7 , if one started with 0.154 M A approximately how much A and B would there be after equilibrium had been established? a. very little A, 0.154 M B b. 0.126 M A; 0.027 M B c. 0.154...
April 6, 2014

CHEMISTRY
Method for getting correct answer for this? Thank you! A mixture containing an initial concentration of 0.1877 M for H2 and 0.1432 M for Cl2 is allowed to come to equilibrium (see reaction below). What must be the equilibrium concentration of HCl? H2(g) + Cl2(g) ↔ 2HCl(g...
April 6, 2014

CHEMISTRY
If an explanation for correct answer could be provided, that would be great! Which equilibrium constant indicates that the reaction will produce mostly products? a. Kc = 3.46x10-6 b. Kc = 1.96x10+7 c. Kc = 0.319 d. Kc = 0.37
April 6, 2014

CHEMISTRY
The initial concentration of PCl5 was 0.1983 M. It was allowed to decompose at some temperature until equilibrium had been attained (see reaction below). What must be the equilibrium concentration of PCl3? PCl5(g) ↔ PCl3(g) + Cl2(g) Kc = 0.0580 a. 0.1162 M b. 0.0496 M c...
April 6, 2014

CHEMISTRY
To what temperature would the reaction below need to be heated to have a rate constant of 8.474e-4 M-1s-1 if the rate constant was 2.7000e-4 M-1s-1 at 327.00°C and the activation energy was 166.000 kJ/mol? H2(g) + I2(g) ↔ 2HI(g) a. 609.24°C b. 336.09°C c. 348...
April 6, 2014

Br2(l)+Cl2(g) (double arrow) 2BrCl(g) dH=+29.4 kJ/mol I am having trouble understanding this. Will the system shift left, right, or unchanged and why? a.Increasing Temp. b. Increasing pressure in flask by adding Ar. c. Increasing volume of flask d. Adding Br2(l)...is answer ...
February 12, 2014

Chemistry
Calculate the number of grams of xenon in 3.566 g of the compound xenon tetrafluoride.
February 5, 2014

Chemistry
Calculate the formula mass for each of the following halogen compounds to five or more significant figures:? bake asked 5 months ago (a) NaIO3 (antiseptic) (b) CCl2F2 (former refrigerant)
February 5, 2014

Chemistry
Calculate the number of grams of xenon in 3.566 g of the compound xenon tetrafluoride.
February 5, 2014

Abby
how do i solve for Tf?
December 5, 2013

Abby
If you have 320.0 mL of water at 25.00 °C and add 140.0 mL of water at 95.00 °C, what is the final temperature of the mixture? Use 1.00 g/mL as the density of water.
December 5, 2013

Pam
A 56.59 g sample of a substance is initially at 20.5 °C. After absorbing 1267 J of heat, the temperature of the substance is 116.5 °C. What is the specific heat (c) of the substance?
December 5, 2013

Lauren
Convert the following energy units. 905 kJ to J 2970 kcal to kJ 5.21 × 106 J to kcal
December 5, 2013

Chemistry
Electron exhibiting a particle wavelength of 5.2 x 10-9 are emitted from hydrogen atoms after interaction with high energy photons. Assuming that the electrons in the hydrogen atom were in their ground state prior to interaction, determine the wavelength of the photon which ...
October 13, 2013

Idontgetit
The value of the equilibrium constant, Kc, at a certain temperature is 8.33 x 10-4. Would the reaction as represented by the chemical equation favor reactants or products? Enter P or R. Cl2CO(g) = CO(g)+Cl2(g)
October 2, 2013

Idontgetit
At 1650 °C the value of Kc for the equilibrium represented by the balanced equation is 2.38 x 10-1. Calculate the value of Kp at the same temperature. Express answer in scientific notation. CO(g)+H2O(g) = CO2(g)+H2(g) ___ x 10 ____
October 2, 2013

Idontgetit
At 565 K the value of Kp for the equilibrium represented by the balanced equation is 2.00 x 10-1. Calculate the value of Kc at the same temperature. Express answer in scientific notation. PCl3(g)+Cl2(g) = PCl5(g) ____ x 10 _____
October 2, 2013

Idontgetit
The value of the equilibrium constant, Kc, at a certain temperature is 2.56 x 10-1. If the reaction quotient for a mixture of these species at the same temperature is found to be 9.90 x 10-4, would the mixture yield more products, more reactants or is it at or near equilibrium...
October 2, 2013

Idontgetit
The value of the equilibrium constant, Kc, at a certain temperature is 2.50 x 102. If the reaction quotient for a mixture of these species at the same temperature is found to be 7.37 x 100, would the mixture yield more products, more reactants or is it at or near equilibrium? ...
October 2, 2013

Idontgetit
The value of the equilibrium constant, Kc, at a certain temperature is 2.56 x 10-1. If the reaction quotient for a mixture of these species at the same temperature is found to be 9.90 x 10-4, would the mixture yield more products, more reactants or is it at or near equilibrium...
October 2, 2013

Idontgetit
The value of the equilibrium constant (Kp) as represented by the first chemical equation is 2.00 x 10-2 at 730 K. Calculate the value of the equilibrium constant (Kp) for the second equation at the same temperature. Express answer in scientific notation. 2HI(g) = H2(g)+I2(g) ...
October 2, 2013

B
For a solution of 3.3 M H2CO3 (Ka = 4.4 × 10-7), calculate: (a) [H+] ____?______M (b) pH _____??______ (c) percent ionization ______?______%
April 29, 2013

organic chemisty
write raction of benzoic acid with propylamine
April 21, 2013

Alan
Mark below all of the statments that correctly describe the physical properties of glass. Glasses do not have slip systems. Glasses consist of both covalent and ionic bonding. Glasses are brittle at room temperature. Glasses are amorphous and have no long range symmetry. The ...
April 13, 2013

Chem
in a 0.01 M solution of 1.4 butanedicarboxylic acid, (Ka1=2.9x10^-5, Ka2=5.3x10^-6), which species is present in the lowest concentration?
March 19, 2013

Chemistry 104
What is the percent ionization of a solution prepared by dissolving 0.0286 mol of chloroacetic acid in 1.60 L of water? For chloroacetic acid ,Ka=1.4x10^-3
March 19, 2013

Chem
What is the equilibrium concentration of chloroacetic acid in a solution prepared by dissolving 0.0314 mil of chloroacetic acid in 1.10L of water? For chloroacetic acid, Ka= 1.4X10^-3
March 19, 2013

Chem
Hypobromous acid,HOBr, has acid -ionization constant of 2.5 X 10^-9 at 25 Celsius . What is the pOH of a 0.63 M HOBr solution? A4.40 B3.87 C5.20 D9.60 E10.13 I'm getting two answers between A or B
March 19, 2013

Chemistry
the hydronium ion concentration of a 0.050 M solution of a weak acid is 5.9 X 10^-3 M. the acid-dissociation constant is 1.37 X 10^-4 at 25 celsius. what is the pH of this solution? A. 0.077 B. 1.30 C. 2.23 D. 3.86 E. 5.13
March 18, 2013

12th science
How will you prepare potassium per magnate.
February 9, 2013

chemistry
Alexandra decides to climb Mt. Krumpett, which is 5000 high. She determines that this will require a total of 3600 of energy for the trip. For her food supply, she decides to take nutrition bars. The label states that each bar contains 50 of carbohydrates, 10 of fat, and 40 of...
February 6, 2013

Chemistry
How many grams of sucrose are needed to make 875 mL of a 39.0% (w/v) sucrose solution?
January 27, 2013

Chemistry
I have all of the answers but this one so if anyone knows this answer, i can trade you :) I tried using the formulas that were posted but i ended up with a weird answer that didn't work.... A photon interacts with a ground state electron in a hydrogen atom and is absorbed...
January 13, 2013

Mary
Can someone please tell me the heat of fusion for Lauric Acid, Oxalic Acid, and Cetyl Alcohol? I've looked and can't find them anywhere! Thanks!
January 13, 2013

Chemistry
The half-life of a first order reaction is determined to be 92.0 years. How long will it take for the concentration of the reactant to reach 2% of its initial value?
December 15, 2012

Chemistry
Write equatios for the ionization of the following acids. (a)HF , (b)H2SO3 , (c)CH3COOH , (d)HNO3.
December 7, 2012

Jennifer
How to balance the following equation: I2 + Cl- = ?
November 28, 2012

Chemistry
THX SO MUCH!
June 14, 2012

Chemistry
A solution of AuCl- is mixed with a solution of Sn2+ under standard conditions. What is the equation? the answer is 2AuCl4- + 3Sn2+ -> 3Sn4+ + 2Au + 8Cl- how do i get this? ITS desperate... plz help me! THANK_YOU SO MUCH!
June 14, 2012

Chemistry
What volume of 0.250M KOH is required to titrate 2.30 x 10^3 mol of the weak acid H2C2O4 ? I know the answer is 18.4, but can you show the process?
June 14, 2012

Chemistry
Explain the Hyberdaization scheme for the central atom&the molecular geometry of CO2.
May 5, 2012

Chemistry
A 53 mL sample of a solution of sulfuric acid is neutralized by 37 mL of a 0.18 M sodium hydroxide solution. Calculate the molarity of the sulfuric acid solution. Answer in units of mol/L
March 24, 2012

Chemistry
Calculate DeltaHrxn for the following reaction: C + H2O --> CO + H2 Use the following: C + O2 --> CO2 DeltaH = -393.5 kJ 2CO + O2 --> 2CO2 DeltaH = -566.0 kJ 2H2 + O2 --> 2H2O Delta H = -483.6 kJ DeltaHrxn = ?
March 20, 2012

cemistry
thx but wat is a good way to remember it
January 25, 2012

cemistry
how to identify bond angles
January 25, 2012

chemhelp
ok, thanks
January 24, 2012

chemhelp
could i use it safely at home
January 24, 2012

chemhelp
is LiCl toxic?
January 24, 2012

chemistry
what is the chemical balance equation for the following: Magnesium metal and hydrochloric acid copper matal and hydroshloric acid potassium hydroxide and acetic acid
January 18, 2012

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