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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
You are approaching a stoplight. If the frequency of the light being emitted is approximately 520 THz, what was the wavelength of the light? What color was the light? v = c/λ 520 THz --> 5.2x10^14 Hz 5.2x10^14 Hz = 3.0x10^8 m/s λ = 1.56 x 10^23 m Not sure how to get the ...

Chemistry
What is the energy of a photon in J emitted by the transition from the ni = 4 to the nf = 2 of a hydrogen atom?

chemistry
A 6.0-L flask contains 0.60 g at a temperature of 25°C. What is the pressure (in atm) inside the flask?

Chemistry
A 150ml solution of 0.340M HCl is mixed with a solution of 340ml of 0.175M HNO3. The solution is then diluted to a final volume of 1.00L. How many moles of H+ are present in the final solution?

Chemistry
After the initial 1 mL of 0.2 M FeCl3 (aq) and 1 mL of 0.2 M KSCN (aq) were combined it was then diluted with an additional 130 mL of deionized water. Which way would this dilution cause the equilibrium to shift? Is a dilution going to be a stress in all situations?

Chemistry
A 10.00 g strip of zinc metal is placed in 100. mL of 0.250 M silver nitrate solution. When the reaction that occurs finally ceases, what will be the mass of unreacted zinc metal in the strip? What will be the mass of silver metal that “plates out” of solution (that is, ...

Chemistry
Based on the following observations for 3 unidentified metals (Z, X, and D) and solutions of their metal cations (Zn+ and En+), rank the metals in terms of reducing agent strength, from lowest to highest. -When metal X is placed in an aqueous solution of En+, a dark residue ...

Chemistry (science)
Which compound is likely to have a lower melting/boiling point?Hydrochloric acid or Potassium sulfate? Justify. Now I know that hydrochloric acid has the lower melting and boiling point because it is covalent and potassium sulfate has an ion-ion force acting on it. But the ...

Chemistry
Sup fam, why is SO2 a stronger reducer than Cr3+?

Chemistry (science)
how does the compound type (ionic, polar, non-polar) correlate to its properties (melting/boiling points)? I have a feeling it's something related to the forces acting on them but I'm confused around how.

Chemistry (science)
how does the compound type (ionic, polar, non-polar) correlate to its properties (melting/boiling points)? I have a feeling it's something related to the forces acting on them but I'm confused around how.

Chemistry
The spectrophometer was used to measure the absorbance of each of a series of [FeSa]+ solutions. A standard curve was construnceted by plotting the absorbance vs. concentration (M). The slope and y-intercept were found to be 1496 M-1 and .003, respectively. An aspirin sample ...

Chemistry
Based on the following information, estimate the Ksp of silver bromide at 25°C. Ag+(aq) + e– → Ag(s) E° = 0.80 V AgBr(s) + e– → Ag(s) + Br–(aq) E° = 0.07 V (1) 5 x 10–13 (2) 2 x 10–25 (3) 2 x 10–15 (4) 4 x 10–30 (5) 3 x 10–11 I understand the answer is 1...

chemistry
If you have A + C <--> C + D, and you increase the concentration of A; that means equilibrium will shift to the right. Now does that also mean that concentration of C decreases?

Chemistry
What initial concentration of Cd2+ is required to result in a cell potential of 0.200 V in a voltaic cell constructed by connecting a nickel electrode that is dipped into 1.00 M NiSO4 solution to a cadmium electrode that is dipped into a solution containing the Cd2+ ions?

Chemistry
How many g of KCl are need to make 2.5 L of a 10% (w/v) solution?

chemistry
How many g of NaOH is needed to make 300.0 mL of a 20 % (w/v) solution? please please show all work I'm very lost

chemistry
When iron(ii)hydroxide is mixed with phosphoric acid, iron(ii)phosphate precipitate results. b)if 3.2g of Fe(OH)² is treated with 2.50g of phosphoric acid, what is the limiting reagent and what is the reactant in access? c)How many grams of Fe³(PO⁴)² precipitate can be ...

Chemistry
How many g of NaOH is needed to make 300.0 mL of a 20 % (w/v) solution? I'm so lost right now I have absolutely no clue

Chemistry
Let's say equilibrium shifts to the right, producing more product. I know that that increases products, but does it decrease reactants? Thanks.

Chemistry
In the reaction,C2H4(g) + 3O2(g) =2H2O(g) + 2CO2(g),what is the complete combustion of 12.5cm3 of ethene

Chemistry
Ammonia is often formed by reacting nitrogen and hydrogen gases. How many liters of ammonia gas can be formed from 17.2 L of hydrogen gas at 93.0°C and a pressure of 45.8 kPa??

chemistry
1. In the Thermodynamics of Borax Dissolution experiment, a student quickly transferred a 5.00 mL sample of the saturated borax solution into an Erlenmyer flasks using a pipet and pipet pump after the borax solution had cooled to 35oC. The student rinses the pipet with warm ...

Chemistry
How much oxygen (in grams) will form from 44.2 mg of N2O5? 2N2O5(s) → 4NO2(g) + O2(g) ____× 10^-3(g) O2

Chemistry
A 200-mL solution of KCl(aq) was electrolyzed for 10.0 minutes, producing Cl2 gas at the anode and H2 gas at the cathode. If the pH of the final solution was 12.40, what was the average current (in amps) used?

Chemistry
What is the pressure of a fixed volume of hydrogen gas at 38.8°C if it has a pressure of 1.36 atm at 15.0°C?

Chemistry
How do you prepare 17.2cm³ of 36% conc HCL per dm³ of solution?

chemistry
3. Determine the pH if 0.02 mol of NaOH is added to 1.0L of the buffer described in question #1. question1: 1. How many grams of NaHCO3 should be added to one liter of 0.100 M H2CO3 (Ka = 4.2 x 10-7) to prepare a buffer with pH = 7.00?

chemistry
2. Determine the pH if 0.02 mol of HCl is added to 1.0 L of the buffer described in question #1 question1: 1. How many grams of NaHCO3 should be added to one liter of 0.100 M H2CO3 (Ka = 4.2 x 10-7) to prepare a buffer with pH = 7.00?

chemistry
lactic acid is the avid responsible for the sour test in spit milk. on the basis of combustion analysis, it's percentage composition by mass is 40.00% carbon, 6.71%hydrogen and x% oxygen. a. Calculate the empirical formula of lactic acid b. The molar mass of lactic acid is 90g...

Chemistry
3.65 g of HCl are dissolved in 2lit of the solution find the polarity

Chemistry
For the galvanic cell that uses the reaction 2 Al(s) + 3 Ni2+(aq) → 2 Al3+(aq) + 3 Ni(s) the value of n in the relationship ΔG° = -nFE° is ________.

Chemistry
In the laboratory, a student adds 57.6 mL of water to 10.9 mL of a 0.755 M perchloric acid solution. What is the concentration of the diluted solution ?

Chemistry
How many ml of HCl required to prepare 5% of HCl solution in 750ml water.if HCl is 36% pure and specific gravity is 1.18g/ml?

chemistry
The pH or acidity of liquid is measured in pH, where pH is given by the equation pH=- log C, with C being the concentration of [H+] in multiples of M=1mol/L. Suppose you are given a solution of hydrochloric acid with a pH of 1.7 and asked to increase the pH solution by 1.4. ...

Chemistry
Given the balanced equation: H2 + Cl2 → 2 HCl , how many moles of HCl will be produced if 18.4 g H2 reacts with 127 g Cl2?

chemistry need help so bad seriously help plz
Use Rydbuz equation to calculate the wavelength of the third line in the paschen series of the hydrogen spectrum.give ur answer in Nm. RH=2.18 * 10^-18j, H=6.63 * 10^-34J. Plz help m

chemistry
Describe how you would determine the melting point of a salt of benzoic acid with melting point of 170°c

Chemistry
A solution is labeled 0.450m hcl. What is the h+ for the solution?

Chemistry
what is the balanced equation for Sodium Hydroxide and Water

Chemistry
Use the Henderson Hasselbalch equations to solve for the Ka of the acid. Solution [HX]=0.200M and [NaX]=0.200M. They both have a pH of 4.11.

Chemistry
An ionic compound dissolved in water, separated into its ions according to the following equation: MA2 (s)--> M^+2 (aq) + 2A^- (aq). If the ground state electron configuration of the two ions are similar to those of neon. Ne, and of Kr, the two elements in the ionic ...

Chemistry
How many grams of lithium are required to completely react with 61.9 mL of N2 gas at STP

chemistry help anyone
use Rydbuz equation to calculate the wavelength of the third line in the paschen series of the hydrogen spectrum.give ur answer in Nm. RH=2.18 * 10^-18j, H=6.63 * 10^-34J. Step plz

Chemistry
What should the molar concentrations of benzoic acid and sodium benzoate be in a solution that is buffered at a pH of 4.75 and has a freezing point of -2.0 ∘C? (Assume complete dissociation of sodium benzoate and a density of 1.01 g/mL for the solution.)

chemistry plz help help
Use Rydbuz equation to calculate the wavelength of the third line in the paschen series of the hydrogen spectrum.give ur answer in Nm. RH=2.18 * 10^-18j, H=6.63 * 10^-34J.

Chemistry
0.25 mol dm-3 solution of hydrochloric acid?

chemistry
Iron can be determined gravimetrically by precipitating as Fe(OH)3 and igniting to Fe2O3. The sample to be analyzed is weighed and transferred to a 400-mL beaker where it is dissolved in 50 mL of H2O and 10 mL of 6 M HCl. Any Fe2+ that is present is oxidized to Fe3+ with 1...

College Chemistry
Calculate the pH at the equivalence point in the titration of 55.0 mL of 0.180 M methylamine(Kb = 4.4 × 10−4) with 0.330 M HCl.

chemistry
What is the symbol equation of iron nails with copper sulfate solution.

Chemistry
25.0 g of potassium acetate (CH 3 COOK) are dissolved in 1.00 L of water. Calculate the pH of this solution. (PKa = 4.76 for CH3COOH)

Chemistry
What is the ratio of rate constants at 305k and 300k if the activation energy of a reaction is 58.3kJ/mol

chemistry
How do you rationalize an infrared spectrum of salicylic acid and aspirin? How do you know which is which?

Chemistry
What is the hydrogen ion concentration of a 0.22 M hypochlorous acid solution with Ka = 3.5E-8? The equation for the dissociation of hypochlorous acid is: HOCl(aq) = H+(aq) + OCl-(aq). I keep getting 3.60 as the concentration, but that is the wrong answer. Using ICE: Eq: HOCl...

chemistry
metals with 8-hydroxyquinoline, C9H7NO. After weighing the mixed precipitate, the precipitate is dissolved and the amount of 8-hydroxyquinoline determined by another method. In a typical analysis, a 127.3 mg sample of an alloy containing iron, manganese, and other metals was ...

chemistry
How do you rationalize an infrared spectrum of salicylic acid and aspirin? How do you know which is which?

chemistry
How many grams of NaHCO3 should be added to one liter of 0.100 M H2CO3 (Ka = 4.2 x 10-7) to prepare a buffer with pH = 7.00? I got molefrom.100/1L equal .100mole. where do I go from here?

Chemistry
a group of grade three students, along with their science teacher, were outside the classroom observing plant species. upon observation, the students recognized that some plant leaves were very pale yellow and weak looking while some looked healthy. suggest an appropriate ...

chemistry
What type of chemical reaction is this equation? CuO (s) + [2H+ + SO4 2-](aq) [Cu2+ + SO4 2-] (aq) + H2O (l)

Chemistry
A 152 g sample of ice at –37 degree C is heated until it turns into liquid water at 0 degree C. How do you find the change in heat content in the system? I've found H(I) [Change in heat of the ice] to be 11416.72 but im still stuck on the change of heat for the water.

chemistry
Use the table of complex ion formation constants to calculate the molar concentration of free Fe^2+ in 0.510M aqueous solution of potassium hexacyanoferrate(II) K4(Fe(CN)6) at 25 degrees celsius. I know the answer is 1.96*10^-6 m, but I'm at a loss on how to get there. I've ...

chemistry
the half time of a radioisotope is found to be 4.55 minutes. if the decay follow first order kinetics. what percentage of isotope will remain after 2.00 hours?

chemistry
Give the IUPAC name of thish hydrocarbon ch3ch2c(ch3)2ch2ch2ch2ch3

Chemistry
Neutralization of water containing H2SO4 and HNO3 with CaSO3. What is the pH in water if the volume is 1000 liter and the concentration of H2SO4 is 0,0013 M and concentration of H2SO4 is 0,0010 M ? And how much of CaCO3 is needed for neutralization of the water?

Chemistry
What ratio of molar concentrations of sodium acetate to acetic acid can buffer a solution at a pH of 4.89?

Chemistry
Rank from longest to shortest bond length: Si-O, Si-H, Si-S

Chemistry
how many sigma and pi bonds in hooc-cooh

chemistry
How many grams of iron(II) oxalate dihydrate, Fe(C2O4)·2H2O,mass can be produced when a student begins the synthesis with 3.238 g of ammonium iron(II) disulfate hexahydrate, (NH4)2Fe(SO4)2·6H2O?

Chemistry
Which of the following liquids should be most soluble in water? A) CH3OH b) CH3CH2CH2CH2OH C) CH3CH2CH2CH2CH2CH3 D) CH3OCH3

Chemistry
An aqueous solution of ethyl alcohol is made by transfering 1.32 mL of liquid ethyl alcohol to a 50.0 mL volumetric flask, and then adding enough water to fill the flask to the mark. What is the volume/volume percentage of ethyl alcohol in the solution?

Chemistry
Based on the ratio of mean moles of O2/mol KClO3 what is the chemical equation for the reaction that occurred? Why? Is this conclusion in accord with the mass of the solid product that you obtained? Explain Moles of O2/mol KClO3 = 1.95x10^-2

Chemistry
Calculate the pH of a 1 L buffer solution that contains 0.050 moles of acetic acid and 0.040 moles of sodium acetate to which 0.020 moles of NaOH has been added.

Chemistry
Ka for a weak acid HA = 3.46x10^-8, calculate K for the reaction of HA with OH- HA + OH- = A- + H2O This is an equilibrium question, but I do not understand how to find the equilibrium constant K, from the equilibrium constant of an acid, Ka

Chemistry
How much heat does your body lose when 3.05 g of sweat evaporates from your skin at 25 ∘C? (Assume that the sweat is only water.) The heat of vaporization of water at 25 ∘C is 44.0 kJ/mole. Answer: 3.05g H2O*1mol/18.015gH2O= 0.169mol H2O 0.169mol*44.0kJ/1mol= 7.45kJ

Chemistry
indicate whether the following would increase decrease or have no effect on the solubility of copper (ii) carbonate (ksp - 2.5 x 10^-10) when compared to the solubility of water 1. dissolve it in an acidic solution 2. dissolve it in ammonia, forming a complex 3. dissolve it in...

Chemistry
If you had a 100 mL of 2.00 M HCl and you added 100 mL to it what is the final volume and final concentration? The volume would be 200ml, but would the concentration just stay the same?

Chemistry
Given H2(g) + (1/2)O2(g) ---> H2O(l), dH = -286 kJ/mol, determine the standard enthalpy change for the reaction 2h2O(l) ---> 2H2(g) + O2(g) 2H2O(l) ---> 2H2(g) + O2(g) H2(g) + (1/2) O29g) ---> H2O (l) : dH = -286 kJ/mols 2H2O(l) ---> 2H2(g) + 2O2(g) : would dH ...

Chemistry
Write the balanced chemical reaction (showing appropriate symbols and states) for the chemical reaction with enthalpy change equal to and defined by the quantity dHformation [NH3(g)] N2(g) + 3H2(g) --> 2NH3(g) Is that all the question is asking for?

Chemistry
When .560 g of Na(s) reacts with excess F2(g) to form NaF(s), 13.8 kJ of heat is evolved at standard-state conditions. What is the standard enthalpy of formation of NaF(s)? Start off by balancing the equation: 2Na(s) + F2(s) ---> 2NaF(s) Then make it for one mole Na(s) + (1...

Chemistry
The enthalpy of formation for a substance corresponds to the enthalpy change for a reaction. Write the specific chemical reaction defining the enthalpy of formation of butane: Just checking to make sure this is correct: 4C + 5H2 ---> C4H10

Chemistry
The following ions contain three oxygen atoms: A) carbonate, sulfite, and nitrite B) sulfite, nitrate, and bromate C) sulfate, hypochlorite, and carbonate D) chlorate, iodate, and phosphite I know I can eliminate A and C.

Chemistry
Calculate the amount of heat necessary to raise the temperature of 12.0 g of water from 15.4ºC to 93ºC. The specific heat of water = 4.18 J/gºC. q = ms∆T q = (12.0g) (4.18) (93.0 - 15.4) q = 3892.416 J ??

Chemistry
Potassium is a reactive element. Bromine is a reactive element. Write the complete balanced chemical equation using appropriate chemical symbols for the reaction when potassium reacts with bromine to make a solid product showing correct symbols and states of reactants and ...

Chemistry
Consider 1.00 L of the buffer system that contains 0.200 M hydrocyanic acid(HCN) and 0.150 M sodium cyanide (NaCN). The pKa of hydrocyanic acid is 9.31. What is the [HCN] after 0.020 mol of HCl is added?

chemistry
Write a comlete, balanced chemical equation for the reaction that occurs between aqueous iron(II) sulfate,FeSO4, and aqueous potassium hydroxide

Chemistry
A weather balloon is filled with helium that occupies a volume of 4.39 x 10^4 L at 0.995 atm and 32.0°C. After it is released, it rises to a location where the pressure is 0.720 atm and the temperature is -14.1°C. What is the volume of the balloon at that new location?

Chemistry
The enthalpy of combustion of benzoic acid (C6H5CO2H) is –3228 kJ/mol. The burning of 1.698 g of benzoic acid in a calorimeter causes the temperature to increase by 2.865 ºC. What is the heat capacity (in kJ/ºC) of the calorimeter?

Chemistry-Urgent
A gas at 61°C occupies a volume of 0.67 L. At what Celsius temperature will the volume increase to 1.12 L? whats the answer didn't understand

Chemistry
Given H2(g) + (1/2)O2(g) --> H2O, ∆Hº = -286 kJ/mol, determine the standard enthalpy change for the reaction 2H2O(l) --> 2H2(g) + O2(g). Just checking... should end up with ∆Hº = 572 kJ/mol right??

Chemistry
Given ∆Hºrxn = -1670 kJ/mol for 2Al(s) + (3/2)O2(g) --> Al2O3(s), determine ∆Hº for the reaction 2Al2O3(s) --> 4Al(s) + 3O2(g). I flipped Al(s) + (3/2)O2(g) --> Al2O3(s) to Al2O3(s) --> A(g) + (3/2)O2(s) and multiplied the molar values by 2. I ended up with...

Chemistry
Air trapped in a cylinder fitted with a piston occupies 163.1 mL at 1.08 atm pressure. What is the new volume when the piston is depressed, increasing the pressure by 25%?

Chemistry
The pressure of a sample of helium in a 3.40 L container is 0.988 atm. What is the new pressure if the sample is placed in a 2.15 L container?

Chemistry
A fixed amount of oxygen gas is held in a .500 L tank at a pressure of 4.09 atm. The tank is connected to an empty 1.50 L tank by a tube with a valve. After this valve has been opened and the oxygen is allowed to flow freely between the two tanks at a constant temperature, ...

Chemistry
If the thermometer reads 22 c and this corresponds to 19.8mmhg of water pressure , what is the pressure of a pure gas collected over water if the total pressure is 760 mmhg?next calculate the pressure of the gas and lets assume its hydrogen gas in atm. pressure of pure gas=760...

Chemistry
Which of the following processes is endothermic? a) H2O (g) --> H2O (l) b) 3O2 (g) + 2CH3OH(g) --> 2CO2(g) + 2H2O(g) c) H2O (s) --> H2O (l) d) O2(g) + 2H2(g) --> 2H2O(g) I a guessing b, since energy has to go into the reaction for water to go from a solid to a ...

Chemistry
Write the balanced chemical reaction (showing appropriate symbols and states) for the chemical reaction with enthalpy change equal to ΔHf° [NH3(g)]

Chemistry
The enthalpy of combustion of benzoic acid (C6H5CO2H) is -3228 kJ/mol. The burning of 1.698 g of benzoic acid in a calorimeter causes the temperature to increase by 2.865°C. What is the heat capacity (in kJ/°C) of the calorimeter?

chemistry
A gas sample occupies a container of 25.0 mL with a pressure of 125.1 kPa at room temperature (25.0 °C). The number of moles of this gas in the container is

chemistry
Calculate the thiocyanate concentration at equilibrium if the irone (III) ion concentration is 0.23 M and the complex ion concentration is 0.625 M t equilibrium. Keq= 138M^-1

Chemistry
Calculate the thiocyanate concentration at equilibrium if the irone (III) ion concentration is 0.23 M and the complex ion concentration is 0.625 M t equilibrium. Keq= 138M^-1

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