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August 25, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
You have a 250ml solution of 0.13M calcium iodate. How many grams of potassium iodate need to be added to the solution to begin to precipitate calcium iodate? The solubility product constant for calcium iodate is6.47 *10^-6. B) you have a 250ml solution of 0.13 M calcium ...
Wednesday, November 18, 2015 by anonymous

Chemistry
What is the function of a salt bridge in a galvanic cell? 1. To permit electrons to flow through the solution. 2. To maintain a steady flow of reactants from the cathode to the anode. 3. To form complex ions with the products of oxidation at the anode. 4. To maintain ...
Wednesday, November 18, 2015 by Anonymous

Chemistry
A solution is prepared by dissolving 3.0 × 10-4 mol of AgNO3 and 3.0 × 10-5 mol of K2CrO4 in 1.00 liter of solution. With respect to Ag2CrO4 (Ksp = 1.9 × 10-12), is the resulting solution saturated, supersaturated, or unsaturated? I know you do [Ag][CrO4} but...
Wednesday, November 18, 2015 by Anonymous

Chemistry
a 6.0 mole sample of Ca3(PO4)2 and a 12.0 mole sample of SiO2 react in an evacuated vessel. after one of the reactants is fully consumed, how much of the gas is created? How exactly would you solve this problem? Would you have to find the molar mass of both sides and divide by...
Wednesday, November 18, 2015 by Allison

Chemistry
A chemist prepared a solution by dissolving 52.0 g of hydrated sodium carbonate in water to a total volume of 5.00 dm3. The concentration was determined to be 0.0366 M. Determine the formula of the hydrated sodium carbonate.
Wednesday, November 18, 2015 by Billy

Chemistry
Calculate the value of theshielding constant if the first ionosaton energy of Helium is 3.98x10ᴧ -19 J/mol
Wednesday, November 18, 2015 by Roderick

Chemistry
One half-cell in a voltaic cell is constructed from a silver wire electrode in a .25 M solution of AgNO3 . The other half-cell consists of a zinc electrode in a .001 M solution of Zn(NO3)2. Calculate the cell potential I have no idea and am so stressed, Help please
Wednesday, November 18, 2015 by Anonymous

Chemistry
What is the net ionic equation of potassium carbonate combines with strontium hydroxide?
Wednesday, November 18, 2015 by Anonymous

Chemistry
What is the net ionic equation of potassium carbonate combines with strontium hydroxide?
Wednesday, November 18, 2015 by Anonymous

Intro to Chemistry
Does the Periodic table have any kind of pattern for brittleness? If so, what is it? For example, the elements on the left are more brittle, while the ones on the right are less brittle.
Wednesday, November 18, 2015 by Claire

chemistry
Maximum mass of water in combustion of 20g hydrogen?
Wednesday, November 18, 2015 by Anonymous

chemistry
At room temperature (25 °C), the gas ClNO is impure because it decomposes slightly according to the equation 2ClNO(g) Cl2(g) + 2NO(g) The extent of decomposition is about 4%. Based upon this, the approximate value of ΔG°298 for the reaction at that temperature is ...
Wednesday, November 18, 2015 by annoymous

Chemistry
Silver chloride has Ksp=1.6x10^-10 and silver cheomate has Ksp=9.0x10^-12. We have 1.00 liter of a solution contains both nacl(0.10M) and Na2cro4(0.10M) solid AgNo3 is added slowly and the solution is stirred well. a) which precipitate first Agcl or AgCro4? B)what are the ...
Wednesday, November 18, 2015 by Anonymous

chemistry
please show the step by step for theoretical yield /yield % of 1.963g NaHCO3-Na2CO3
Wednesday, November 18, 2015 by Anonymous

Chemistry
Calculate the pressure of 4.80g of ozone, O3, in a 2.45 L flask at 25 degrees C. Assume that the ozone completely decomposes to the molecular oxygen. 2O3(g) --> 3O2(g) Calculate the pressure inside the flask once the reaction is complete.
Wednesday, November 18, 2015 by Sarah

Chemistry (Check)
What is the volume of the gas in a balloon at -195 degrees C if the balloon has been filled to a volume of 5.0L at 25 degrees C? Vf = 1.3L
Wednesday, November 18, 2015 by Sarah

Chemistry
Calculate the density of methane gas, CH4, in kilograms per cubic meter at 25 degrees C and 956 mmHg. I got .8252 g/L but am getting confused with the converting units.
Wednesday, November 18, 2015 by Sarah

Chemistry - radioactivity
Hello Dr.Bob, could you please help me with this problem: Which of the following nuclides are most likely to decay via beta decay? a)200 78 Pt b)192 78 Pt c)188 78 Pt d)196 78 Pt
Tuesday, November 17, 2015 by Laurus

chemistry!
a) Find the pH at the equivalence point when 40ml of 0.025 M of methylamine (NH2CH3 and Kb = 4.4x10^-4) is titrated with 0.025 M HCl. b) The Kf for the complex ion Ag(NH3)2+ is 1.7x10^7. The Ksp for AgI is 1.5x10^-16. What is the molar solubility of AgI in a solution that is 2...
Tuesday, November 17, 2015 by Freddy

Chemistry (Help)
Calculate the DHrxn of C57H110O6 (s) + O2(g) --> CO2(g) + H2O(l) with DHf. C57H110O6(s) -390.70 O2(g) 0 CO2(g) -393.5 H2O(l) -285.840 I balanced the equation: 2C57H110O6 (s) + 163O2(g) --> 114CO2(g) + 110H2O(l) and my work: DHrxn = [(114x -393.5)+(110x -285.840)] - [(2x...
Tuesday, November 17, 2015 by Anonymous

Chemistry (Help)
Calculate the DHrxn of C6H12O6 (s) + O2 (g) --> CO2 (g) + H2O (l) with DHf. C6H12O6(s) -1260.04 O2(g) 0 CO2(g) -393.5 H2O(l) -285.840 I balanced the equation: C6H12O6 (s) + 6O2 (g) --> 6CO2 (g) + 6H2O (l) and my work: DHrxn = [(6x -393.5)+(6x -285.840)] - [(1x -1260.04...
Tuesday, November 17, 2015 by Anonymous

Chemistry
A student adds 5.50 g of dry ice (solid ) to an empty balloon. What will be the volume of the balloon at STP after all the dry ice sublimes (converts to gaseous )?
Tuesday, November 17, 2015 by Marquette

Chemistry
If you have a 578 g of fat (tristearin) stored in your body, how much heat will be produced when it is metabolized? tristearin is C57H110O6 The chemical reaction: C57H110O6(s) + O2(g) --> CO2(g) + H2O (l) DHf: C57H110O6(s) -390.70 O2(g) 0 CO2(g) -393.5 H2O(l) -285.840 I don...
Tuesday, November 17, 2015 by Anonymous

general chemistry
Determine the concentrations of Na2CO3, Na , and CO32– in a solution prepared by dissolving 2.57 × 10–4 g Na2CO3 in 1.50 L of water. Express all three concentrations in molarity. Additionally, express the concentrations of the ionic species in parts per million...
Tuesday, November 17, 2015 by Anonymous

Chemistry
What is the unit m^-1? The question I'm working on says "an electron in the hydrogen atom makes a transition from an energy state of principal quantum number nt to n=1. If the photon emitted has a wavelength of 95 nm, what is the value of nt? I was trying to use the ...
Tuesday, November 17, 2015 by Quinn

Chemistry
The standard entropy change for 1.00 moles of Ar as it evaporates at -185.7 °C (∆H°-185.7 = 1558 cal mol-1) is? 1. 17.8 J mol-1K-1 2. 87.5 J mol-1K-1 3. 15.0 J mol-1K-1 4. 46.0 J mol-1K-1 5. 74.5 J mol-1K-1 6. none of the previous answers I thought I would use ...
Tuesday, November 17, 2015 by Anonymous

chemistry
Calculate the ionic strength of a solution that contains 1.45g Na3PO4 in 0.500L of solution.
Tuesday, November 17, 2015 by tithi

Chemistry
Calculate the pressure in an evacuated 250mL container at 0 degrees C when the O2 in 1.00 cm^3 of liquid oxygen evaporates. Liquid oxygen has a density of 1.118 g/cm^3.
Tuesday, November 17, 2015 by Sarah

Chemistry
A solution contains 0.50M Nh3 and 1.50 M Nh4cl. What is the maximum concentration of mg2+ that can be present in such a solution without precipitating Mg(oh)2?
Tuesday, November 17, 2015 by Angel

Chemistry
A block of copper of unknown mass has an initial temperature of 69.1 ∘C . The copper is immersed in a beaker containing 93.4 g of water at 21.0 ∘C . When the two substances reach thermal equilibrium, the final temperature is 24.2 ∘C . Find mass of Copper
Tuesday, November 17, 2015 by Judy Blue

Chemistry
Calculate the pH during the titration of 40 ml of 0.1000 M HCl with 0.1000 M NaOH solution after the following additions of base: A.) 28.00 ML B.) 39.80 ML C.) 48.00 ML
Tuesday, November 17, 2015 by Braden

Chemistry
Fuel values, reported in units of KJ/g, are useful in comparing the efficiency of various energy sources on a mass basis. Determine the fuel value of the glucose and the tristearin. Which one, carbohydrates or fats, have the highest fuel value (and hence is the most efficient ...
Tuesday, November 17, 2015 by Anonymous

chemistry
I know everyone guessed i had a few more i couldnt do. Sorry but assistance please: 1.Sucralfate (molecular weight: 2087g/mol) is a major component of Carafate® which is prescribed for the treatment of gastrointestinal ulcers. The recommended dose for a duodenal ulcer is ...
Tuesday, November 17, 2015 by mikey

Chemistry (Help)
Calculate the DHrxn of C57H110O6 (s) + O2(g) --> CO2(g) + H2O(l) with DHf. C57H110O6(s) -390.70 O2(g) 0 CO2(g) -393.5 H2O(l) -285.840 I balanced the equation: 2C57H110O6 (s) + 163O2(g) --> 114CO2(g) + 110H2O(l) and my work: DHrxn = [224mol(-393.5+(-285.840))] - [165mol(-...
Tuesday, November 17, 2015 by Anonymous

Chemistry (Check)
Calculate the DHrxn of C6H12O6 (s) + O2 (g) --> CO2 (g) + H2O (l) with DHf. C6H12O6(s) -1260.04 O2(g) 0 CO2(g) -393.5 H2O(l) -285.840 I balanced the equation: C6H12O6 (s) + 6O2 (g) --> 6CO2 (g) + 6H2O (l) and my work: DHrxn = [12mol(-393.5+(-285.840))] - [7mol(-1260.04+0...
Tuesday, November 17, 2015 by Anonymous

chemistry
41. Ethyne, C2H2, used in welding react with oxygen as shown below.
Tuesday, November 17, 2015 by mark

chemistry
i am working on a practice worksheet and need help with a few i can not understand. please and thank you. I have to post them separately sorry 49.how many grams of water are needed to completely hydrolyze 30.8 g of the ester? A.0.416 g B.30.8 g C.11.3 g D.7.49 g 54. Sodium ...
Tuesday, November 17, 2015 by mark

Chemistry
al(i) Determine the number of moles of Ca2+ present in the titrated sample. (ii) Determine the [Ca2+] and hence the solubility of CaSO4.2H2O in the original 10.0 mL sample. so
Tuesday, November 17, 2015 by Mara

Chemistry
A 10.0 mL sample of supernatant liquid from the system described by equation 1 was titrated with 0.01022 M EDTA solution to an end-point at 16.90 mL. Titration of the blank gave a titre (end-point) at 1.45 mL. Determine the titration volume required to titrate the Ca2+ alone.
Tuesday, November 17, 2015 by Mara

CHEMISTRY
An analysis of a compound gave 40% carbon 3.7% hydrogen. the vapour density of the compound is 30. calculate the empirical and molecula fomular.
Tuesday, November 17, 2015 by NEMUEL

chemistry
How many milliliters of water has been dispensed if the initial buret reading was 0.45 mL and the final is 20.33 mL?
Tuesday, November 17, 2015 by Anonymous

chemistry
how many grams of NaCl should be added in 15ml which must have a final concentration of 10mM
Tuesday, November 17, 2015 by Josh

Chemistry
Describe an experiment using only hot and cold water that would allow you to verify that the heat capacity of a coffee-cup calorimeter is about 1.0x10^1 J/oC. Be specific.
Tuesday, November 17, 2015 by Wex

Chemistry
Experimental results for hydrochloric acid (neutralization) are always a little less negative than the usual constant of heat of neutralization for strong acids and bases (-57.35kJ). Suggest reasons for this.
Tuesday, November 17, 2015 by Wex

chemistry
anyone know how to do this and which choice is correct?thank you so much in advance. Use the Henderson-Hasselbalch equation to calculate the pH of a buffer that is 0.350 M acetic acid and 0.250 M sodium acetate. a.4.89 b.4.47 c.4.59 d.none of the above is is not 4.74
Tuesday, November 17, 2015 by anna

chemistry
The following reaction can be written as the sum of two reactions, one of which relates to ionization energy and one of which relates to electron affinity: Li(g)+F(g)→Li+(g)+F−(g) What is the reaction that corresponds to the first ionization energy of lithium, Li? ...
Monday, November 16, 2015 by rabia

Chemistry
Ice has negative caloric count. How much energy, in each of the following units, does your body lose from melting 175g of ice? Express your answers in J, kJ, cal, Cal
Monday, November 16, 2015 by Nicole

Chemistry (Check)
Calculate the DHrxn of C57H110O6 (s) + O2(g) --> CO2(g) + H2O(l) with DHf. C57H110O6(s) -390.70 O2(g) 0 CO2(g) -393.5 H2O(l) -285.840 I balanced the equation and my work: DHrxn = [224mol(-393.5+(-285.840))] - [165mol(-390.70+0)] = -87706.66 KJ/mol Is this right? If not, ...
Monday, November 16, 2015 by Anonymous

Chemistry (Check)
Calculate the DHrxn of C6H12O6 (s) + O2 (g) --> CO2 (g) + H2O (l) with DHf. C6H12O6(s) -1260.04 O2(g) 0 CO2(g) -393.5 H2O(l) -285.840 I balanced the equation and my work: DHrxn = [14mol(-393.5+(-285.840))] - [7mol(-1260.04+0)] = -690.48 KJ/mol Is this right? If not, what ...
Monday, November 16, 2015 by Anonymous

Chemistry
Determined at which temperature is the solubility of KNO3 at 60 grams per 100 grams of water
Monday, November 16, 2015 by Tommy

Chemistry (Check)
The bond strengths of the compounds HF, HCl, HBr, and HI are as follows: compound bond strength, kJ/mol HF 569.87 HCl 431.62 HBr 366.35 HI 298.407 Briefly explain why the bond strengths are ranked in this order. My guess is: They are ranked in this order because of the ...
Monday, November 16, 2015 by Anonymous

Chemistry
What is the concentration of lead ions in a solution if they are completely precipitated from 36.3 mL of solution by 29.6 mL of 0.35M potassium iodide.
Monday, November 16, 2015 by Sam

chemistry
Determine the mass of copper that has the same number of atoms as there are in 15.46 mg of gold. Answer in units of mg.
Monday, November 16, 2015 by Quinton

chemistry
Determine the quantity (g) of pure CaCl2 in 7.5 g of CaCl2*9H2O
Monday, November 16, 2015 by ali

Chemistry
A 22.6 mL sample of a weak monoprotic acid, HX, requires 50.0 mL of 0.050 M NaOH to reach the equivalence point. After the addition of 30.0 mL of NaOH, the pH is 4.90. What is the Ka of HX?
Monday, November 16, 2015 by Lexi

chemistry
at 25 celcius, how many dissociated OH ions are there in 8.0x10^-1 L of aqueous solution with pH 4.73?
Monday, November 16, 2015 by Christine

Chemistry
Explain what would happen if a saturated solution of kno3 at 50°c is heated
Monday, November 16, 2015 by Miya pierre

Chemistry
2.0 gram of C2H4 is reacted withO2. What mass of water is produced?
Monday, November 16, 2015 by Cindy

chemistry
Which is the correct expression for Keq when the chemical reaction is as follows: N2 + 3H2 2NH3.
Monday, November 16, 2015 by luis

Chemistry
How do I know the order of placing dots on the lewis structure? Please give an example.
Monday, November 16, 2015 by Rucha

Chemistry
State the kind of intermolecular forces that would occur between the solute and solvent in barium nitrate (ionic). Check all that apply. ion-dipole hydrogen bonding dispersion dipole-dipole
Monday, November 16, 2015 by Desiree Torres

Analytical Chemistry
I have a 0.00156 M solution of CuSO4*5H2O in water (from 0.0398 g of CuSO4*5H20 in 100 mL of water). How would I calculate the ppm of Cu of that solution from that information? Now if I were to find ppm of Cu in different aliquots of this stock solution (5 mL, 10 mL, etc.) how...
Monday, November 16, 2015 by Ronnie

Chemistry
Experimental results for hydrochloric acid (neutralization) are always a little less negative than the usual constant (-57.35kJ). Suggest reasons for this.
Monday, November 16, 2015 by Wex

chemistry
What is the value of the equilibrium constant at 500 °C for the formation of NH 3 according to the following equation? N 2 ( g ) + 3H 2 ( g ) ⇌ 2NH 3 ( g ) An equilibrium mixture of NH 3 ( g ), H 2 ( g ), and N 2 ( g ) at 500 °C was found to contain 1.35 M H 2 , ...
Monday, November 16, 2015 by mayuri

chemistry
A reaction is represented by this equation: 2W( aq ) ⇌ X( aq ) + 2Y( aq ) K c = 5 × 10 −4 (a) Write the mathematical expression for the equilibrium constant. (b) Using concentrations of ≤1 M , make up two sets of concentrations that describe a mixture ...
Monday, November 16, 2015 by mayuri

chemistry
A reaction is represented by this equation: 2W( aq ) ⇌ X( aq ) + 2Y( aq ) K c = 5 × 10 −4 (a) Write the mathematical expression for the equilibrium constant. (b) Using concentrations of ≤1 M , make up two sets of concentrations that describe a mixture ...
Monday, November 16, 2015 by mayuri

Chemistry
Hydrocarbon burn in excess oxygen yields 4.4g of carbon(iv)oxide and 2 of 7g of water. Find the empirical formula of hydrocarbon
Monday, November 16, 2015 by Prudent

chemistry
0.60g of a gaseous hydrocarbon E when completely burnt in oxygen gave 1.76g of carbon dioxide. WHAT IS THE EMPIRICAL FORMULA OF E?
Monday, November 16, 2015 by viky

Science: Chemistry
How many kilojoules are released when 115 g of Si reacts with chlorine? Si(s)+2Cl2(g)→SiCl4(g)ΔH=W​22;657kJ
Sunday, November 15, 2015 by Alex

Science: Chemistry
Pentane (C5H12) burns in oxygen to produce carbon dioxide and water. C5H12(g)+8O2(g)→5CO2(g)+6H2O(g) Calculate the mass of CO2 that can be produced if the reaction of 38.5 g of pentane and sufficient oxygen has a 58.0 % yield.
Sunday, November 15, 2015 by Alex

Chemistry
A 0.120 g sample of a diprotic acid of unknown molar mass is dissolved in water and titrated with 0.1218 M NaOH. The equivalence point is reached after adding 12.4 mL of base. What is the molar mass of the unknown substance?
Sunday, November 15, 2015 by Jorge

chemistry Dr BOB
In many residential water systems, the aqueous Fe3+ concentration is high enough to stain sinks and turn drinking water light brown. The iron content is analyzed by first reducing the Fe3+ to Fe2+ and then titrating with MnO4- in acidic solution. Fe2+(aq) + MnO4-(aq) ? Mn2+(aq...
Sunday, November 15, 2015 by Dalton

Analytical Chemistry
I have a 0.00156 M solution of CuSO4*5H2O in water (from 0.0398 g of CuSO4*5H20 in 100 mL of water). How would I calculate the ppm of Cu of that solution from that information?
Sunday, November 15, 2015 by Ronnie

Chemistry 102
The average human body contains 6.00 L of blood with a Fe2+ concentration of 2.00×10−5 M . If a person ingests 6.00 mL of 16.0 mM NaCN, what percentage of iron(II) in the blood would be sequestered by the cyanide ion?
Sunday, November 15, 2015 by Kyle

Chemistry
What materials would be produced in the electrolysis of the following reagents? Please make sure that you correctly balance the equations! Also, please note the states of the reagents. NaCl (aq) --> NaCl (l) --> KBr (l) -->
Sunday, November 15, 2015 by Evan

Chemistry
Given: PbSO4 + 2e− Pb + SO42− E° = -0.356 V PbO2 + 4H+ + SO42− + 2e− PbSO4 + 2H2O E° = 1.685 V Determine the cell voltage of the lead storage battery when the concentration of sulfuric acid is 4.00 M. Where do I start, thank you
Sunday, November 15, 2015 by Anonymous

chemistry
The average chemical bond energy in DNA molecules is about 300.00Kj per 6.02E23 bonds, estimate the number of chemical bonds that can be ruptured by a 1E-9m x-ray photon.
Sunday, November 15, 2015 by Brooke N

Chemistry
Calculate the standard enthalpy change for the reaction 2A+B⇌2C+2D Use the following data: Substance ΔH∘f (kJ/mol) A -251 B -403 C 213 D -511 My thoughts: [(2)(-511)+(213)(2)]-[(2)(-251)+(-403)]=​309kJ (but apparently that is not the correct answer) What...
Sunday, November 15, 2015 by Miranda

Chemistry
A 0.120 g sample of a diprotic acid of unknown molar mass is dissolved in water and titrated with 0.1218 M NaOH. The equivalence point is reached after adding 12.4 mL of base. What is the molar mass of the unknown acid?
Sunday, November 15, 2015 by Jorge

Chemistry
1. A hypothetical pure element consists entirely of two isotopes. The natural percent abundance of the isotope with mass 25.5 u is 86.1%. The other isotope has mass 29.2 u. Calculate the atomic weight of the naturally occurring element. 2. Suppose that a hypothetical element ...
Sunday, November 15, 2015 by Melissa

Chemistry
Which molecule contains a polar covalent bond? a)C2H4 b)ZnS c)LiI d)NBr3 e)AgI
Sunday, November 15, 2015 by Mark

Chemistry Dr. BOB
In many residential water systems, the aqueous Fe3+ concentration is high enough to stain sinks and turn drinking water light brown. The iron content is analyzed by first reducing the Fe3+ to Fe2+ and then titrating with MnO4- in acidic solution. Fe2+(aq) + MnO4-(aq) ? Mn2+(aq...
Sunday, November 15, 2015 by Dalton

chemistry
A standard sodium carbonate solution is prepared in a 250 cm^3 volumetric flask during a titration,20 cm^3 of a 0,1 mol.dm^-3 nitric acid solution neutralises 25 cm^3 of the above standard solution according to the following balanced equation 2HNO3(aq) Na2CO3(aq)=>2NaNO3(aq...
Sunday, November 15, 2015 by alex

Chemistry
10000 tonnes of iron reacted in a blast furnace Fe2O3 calculate the typical mass of iron produced each day
Sunday, November 15, 2015 by Anonymous

Chemistry
A student performed an experiment to determine the molecular weight of a gaseous compound. Using the ideal gas law PV = nRT, and knowing the pressure, temperature, and volume of the vapor, the student calculated the number of moles of gas, n, to be 0.0443 mol. The weight of ...
Sunday, November 15, 2015 by Ericka

Chemistry
A 0.120 g sample of a diprotic acid of unknown molar mass is dissolved in water and titrated with 0.1218 M NaOH. The equivalence point is reached after adding 12.4 mL of base. What is the molar mass of the unknown acid?
Sunday, November 15, 2015 by Jorge

chemistry
Consider an atom traveling at 1% of the speed of light. The de Broglie wavelength is found to be 9.50 × 10–3 pm. Which element is this?
Saturday, November 14, 2015 by Anonymous

Chemistry
You have a 250ml solution of 0.13M calcium iodate. How many grams of potassium iodate need to be added to the solution to begin to precipitate calcium iodate? The solubility product constant for calcium iodate is6.47 *10^-6. B) you have a 250ml solution of 0.13 M calcium ...
Saturday, November 14, 2015 by Jack

Chemistry
Given the following half-reactions and their standard reduction potentials, Ni2+ + 2e− Ni E° = -0.25 V 2H+ + 2e− H2 E° = 0.00 V Ag+ + e− Ag E° = 0.80 V a spontaneous reaction will occur between: a. Ni2+ and H2 b. H+ and Ag c. Ag+ and Ni d. Ni2+ ...
Saturday, November 14, 2015 by Anonymous

Chemistry
What is the frequency of the photons emitted by hydrogen atoms when they undergo transition from n=4 to n=3?
Saturday, November 14, 2015 by Terrill

chemistry
draw a diagram showing the arrangement of the valency electrons in a molecule of the covalent compound arsine,ash3 use o to represent an electron from aresenic
Saturday, November 14, 2015 by ahmad

Chemistry
What is the minimum volume of 2.6 M HBr required to completely dissolve 35.0 g of potassium metal?
Saturday, November 14, 2015 by Jorge

chemistry
In many residential water systems, the aqueous Fe3+ concentration is high enough to stain sinks and turn drinking water light brown. The iron content is analyzed by first reducing the Fe3+ to Fe2+ and then titrating with MnO4- in acidic solution. Fe2+(aq) + MnO4-(aq) ? Mn2+(...
Saturday, November 14, 2015 by Dalton

chemistry
Calculate the volume occupied by 7g of nitrogen gas at 27 degree c and 750 mm of hg pressure
Saturday, November 14, 2015 by g srinivasa rao

Chemistry
When sodium chloride, NaCl, is added to water, it forms a solution. Rank the steps involved in the dissolution of salt in water from first step to last step. To rank items as equivalent, overlap them. a.) NaCl crystal is added to water b.) NaCl solution c.) The Na ions are ...
Saturday, November 14, 2015 by LuigiR

Chemistry
You have a large amount of 8.00 M stock solution. You need 1.60 L of 3.00 M solution for an experiment. How would you prepare the desired solution without wasting any stock solution? A.) Start with 1.60 L of water. Add stock solution until you reach a total volume of 2.56 L . ...
Saturday, November 14, 2015 by LuigiR

chemistry
calculate the pH of 5M aqueous ammonia. Given kb=1.8 x 10^-5
Saturday, November 14, 2015 by Nor Syafinas

Chemistry
2.1 g of a hydrocarbon fuel is burned in a calorimeter that contains 280 grams of water initially at 25.00◦C. After the combustion, the temperature is 26.55◦C. How much heat is evolved per gram of fuel burned? The heat capacity of the calorimeter (hardware only) is...
Friday, November 13, 2015 by Amy

Chemistry
A piece of metal of mass 25 g at 94◦C is placed in a calorimeter containing 57.4 g of water at 24◦C. The final temperature of the mixture is 34.2 ◦C. What is the specific heat capacity of the metal?Assume that there is no energy lost to the surroundings. ...
Friday, November 13, 2015 by Amy

Chemistry
Pyrites, FeS2, are a pollution-causing impurity in some coals. Upon combustion, the following rxn takes place: 2FeS2 + 5O2 à 4SO2 + 2FeO What volume of 6.0 M NaOH would be required to react with the SO2 produced from 1000 kg of coal containing 0.050% by mass of pyrite ...
Friday, November 13, 2015 by Mary White

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