Tuesday
January 17, 2017

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Will 1 L of 1 M NaCl contain more chloride ions than .5L of 1M MgCl2? Explain.
Tuesday, April 19, 2016 by Jordan

Chemistry
If a tire can hold 19L of air at 175 kPa and 25° C, what volume of air can the tire hold at 215 kPa and 30° C? Possible answers: A. 13.7 L B. 15.7L C. 23.0L D. 19L
Tuesday, April 19, 2016 by Anonymous

Chemistry
Two electron configuration: Mg(Ne)3s^2 Zn(Ar)4s^2 3d^10 Using the configurations, explain the difference in relative reactivity of the 2 metals ( which are Mg and Zn)
Tuesday, April 19, 2016 by Rose

Chemistry
The ions Cr3+ and O2- combine to form the ionic chromium oxide. in what proportions do these ions combine to produce a neutral compound?
Tuesday, April 19, 2016 by Monica

Chemistry
Which pair of compounds will form a solution?Benzene (C6H6) and hexane (C6H14)Na2SO4 and benzene (C6H6)NaCl and hexane (C6H14)H2O and CCl4More than one of the combinations above will form solutions.
Tuesday, April 19, 2016 by Kelly

Chemistry
Name two solutions that can be used to precipitate out the following: PbCl2 Would I just use a random soluble compound and write a total ionic equation
Tuesday, April 19, 2016 by AlphaPlus

Chemistry
What mass of sodium phosphate is needed to produce 75.00 g of solid product?
Tuesday, April 19, 2016 by Shania

Chemistry
Two electron configuration: Mg(Ne)3s^2 Zn(Ar)4s^2 3d^10 Using the configurations, explain the difference in relative reactivity of the 2 metals ( which are Mg and Zn)
Tuesday, April 19, 2016 by Rose

chemistry
Calculate the standard entropy change for the reaction of calcium oxide with water to form calcium hydroxide: CaO(s) + H2O(ℓ) → Ca(OH)2(s) at 298 K. ∆S ◦ m ∆H◦ f J K·mol? kJ mol? CaO(s) 39.75 −635.09 H2O(ℓ) 69.91 &#...
Tuesday, April 19, 2016 by Anonymous

Chemistry
Balance the reaction step-wise: As2S3(s) + NO3^- + H^+(aq) to AsO4(aq) + S(s) + NO(g) + H2O(l)
Tuesday, April 19, 2016 by Subhan

Chemistry
If a half life of a radioactive element is twelve years,find the decay constant
Tuesday, April 19, 2016 by Undie vickvieny

Chemistry
In a student's experiment, when 40 mL of 6% (w/w) hydrogen peroxide solution was reacted with 10 mL 0.5 M FeCl3 solution, a ΔrH of -3,382 J was calculated. Calculate ΔH for this reaction in kJ mol-1. Give your answer to 2 decimal places, do not include the units ...
Tuesday, April 19, 2016 by Anon

Chemistry
Use the collision theory to explain the increase in rates of the other reactions
Tuesday, April 19, 2016 by Rose

Chemistry - Oxidation-Reduction reactions
how would your calculation of the molarity of KMnO4 be affected if you had added twice as much sulfuric acid and water as was called for in the procedure?
Tuesday, April 19, 2016 by Anonymous

Chemistry
t takes 572 kJ of energy to decompose 2.00 mol of liquid water. How much energy does it take to decompose 54.0 mol of water? 2H2O(l)+572kJ→2H2(g)+O2(g)
Monday, April 18, 2016 by Josh

Chemistry
The estimated proven world oil reserves in 2013 were 1526 billion barrels. The world annual rate of use was 32.6 billion barrels. How long will these reserves last if this rate of use continues? (The rate of use is actually likely to increase.)
Monday, April 18, 2016 by Josh

Chemistry
Burning 2.00 mol of hydrogen releases 483.6 kJ of energy. Determine how much energy, in kilojoules, must be supplied to convert 5.00 mol of water vapor into hydrogen gas and oxygen gas.
Monday, April 18, 2016 by Josh

chemistry
Determine delta G naught at 298.15K for a 0.50 V voltaic cell if n=3 for that cell.
Monday, April 18, 2016 by Kaitlin

Chemistry
What is the molar solubility of Mg(OH)2 in a solution containing 0,10 M NH3 ? Ksp Mg(OH)2 = 1.2x10^-11 Kp NH3 = 1.8x10^-5
Monday, April 18, 2016 by Kevin

Chemistry
What is the molar solubility of Mg(OH)2 in a solução containing 0,10 M NH3 ? Ksp Mg(OH)2 = 1.2x10^-11 Kp NH3 = 1.8x10^-5
Monday, April 18, 2016 by Kevin

Chemistry
The molar solubility of a generic substance, Mg(OH)2 ksp = (1.2x10^-11) in 0.10 M NH3 Kb = 1.8 x 10^-5 help me please =)
Monday, April 18, 2016 by Damon

Chemistry
A 50 g piece metal is placed in 250 g of methanol at 0 °C. The methanol is warmed to a temperature of 5 °C. What is the specific heat of the metal?
Monday, April 18, 2016 by Mary

Chemistry
Could someone please help guide me through this question: A 1.047 g sample of He(g) is found to occupy a volume of 8.446 L when collected over hexane at 25.0 ∘C and 739.6 mmHg barometric pressure. Use these data to determine the vapor pressure of hexane at 25 ∘C.
Monday, April 18, 2016 by Rima

Chemistry
Calculate the boiling temperature of a 0.50 M solution of sucrose. Assume that the concentration is 0.50 m.
Monday, April 18, 2016 by Caleb

Chemistry
Write balanced reaction for the following metal acid reaction A) Mg and HCI B) Zn and HCI
Monday, April 18, 2016 by Rose

AP Chemistry
Consider the following reaction: PbCl2 + 2 NaOH → Pb(OH)2 + 2 NaCl What would be the major species observed floating in solution after one mole of PbCl2 and 2 moles of NaOH are mixed in aqueous solution? 1. Na+ ions, Cl− ions and H+ ions 2. Pb2+ ions, Cl− ...
Monday, April 18, 2016 by Sam

chemistry
0.717g of potassium dihydrogen phosphate in 500ml concentration in ppm
Monday, April 18, 2016 by junaid

chemistry
Consider the equilibrium reaction CO(g)+H2O(g)⇋CO2(g)+H2(g) Determine how each change in the left-hand column will stress the system and in which direction the equilibrium reaction will shift in response.
Monday, April 18, 2016 by Jean

chemistry
commercially available concentrated hydrochloric acid is 37.0% w/w HCl. Its density is 1.18 g/mL. Using this information calculate (a) the molarity of concentrated HCl, and (b) the mass and volume (in mL) of solution containing 0.315 moles of HCl.
Monday, April 18, 2016 by Anonymous

Chemistry
How much sweat (in mL) would you have to evaporate per hour to remove the same amount of heat a 120 W light bulb produces? (1W=1J/s.)
Monday, April 18, 2016 by Lucie

Chemistry
0.4276-g sample of a potassium hydroxide – lithium hydroxide mixture requires 31.20 mL of 0.3315 M HCl for its titration to the equivalence point. What is the mass percent lithium hydroxide in this mixture? 1.) 0.03120 L x 0.3315= 0.010343 moles HCl I'm ...
Sunday, April 17, 2016 by Anonymous

Chemistry
How+much+zinc+%28density+7.14+g%2Fcm3%29​+is+required+to+produce+13+grams+of+zinc​+chloride
Sunday, April 17, 2016 by Brenda

chemistry
Aqueous sodium sulfate reacts with aqueous barium chloride to produce solid barium sulfate and aqueous sodium chloride. the solution contains 3.44g of barium chloride. you have a 0.282M solution of sodium sulfate. determine the volume of the sodium sulfate solution necessary ...
Sunday, April 17, 2016 by sara

Chemistry
For the reaction 2 NO (g) + Cl2 (g) → 2 NOCl (g) If the concentration of NO is tripled, the rate of the reaction increases by a factor of nine. If the concentration of Cl2 is cut in half, the rate of the reaction is decreased to half the original rate. Find the order of ...
Sunday, April 17, 2016 by Nicole

Chemistry 101
Write the molecular, total ionic, and net ionic, for the reaction. 1). Aqueous sodium carbonate is reacted with aqueous nickle (11) chloride. 2). Aqueous potassium hydroxide is mixed with aqueous hydrochloric acid.
Sunday, April 17, 2016 by mike

Chemistry
[2.0 mol (-285.91 kJ/mol)] + [1.0 mole (0 kJ/mol)] - [1.0 mole (50.61 kJ/mol)] = ??? I came up with the answerof -622.43 but im not sure what the correct amount of significant figures would be and why? would 0 kj/mol be considered significant making the answer -600? what would...
Sunday, April 17, 2016 by David

Chemistry
Does either E1 and E2 involve a retention or inversion of stereochemistry? What happens to the stereochemistry in these reactions? I know stereospecificity is important for the reaction to occur, but I don't know what these means for the stereochemistry after the reaction ...
Sunday, April 17, 2016 by Anonymous

chemistry
what volume of glycerine C3H8O3, with a density of 1.26 g/mL should be taken to obtain 2.50 ml of glycerine?
Sunday, April 17, 2016 by Jonathan

Chemistry
A 110g piece of copper is heated and the temperature changes from 38C to 172C. The heat absorbed is 686 cal. What is the specific heat of copper. I think the answer is .385, but I have tried 100 different ways to get this answer or anything close, and I am lost..it is just a ...
Sunday, April 17, 2016 by lulu

chemistry
What is the equilibrium constant for 2A + 3B (double arrow) =4C Is it (C)^c/ (A)^a (B)^b
Sunday, April 17, 2016 by lulu

chemistry
Calculate the energy needed to produce 10 moles of Cl2O7 using this balanced equation. 2Cl +70+ 100kCal==2ClO7 please explain steps if I needed to calculate for 7 moles, how would it change?
Saturday, April 16, 2016 by lulu

chemistry
what is the concentration of 24.5g of Ca(NO3)2 in 244mL of water
Saturday, April 16, 2016 by sara

Chemistry
Calculate the pH of the buffer formed by mixing equal volumes [C_2H_5NH_2]= 1.68 M with [HClO_4]= 0.966 M . Kb=4.3×10−4.
Saturday, April 16, 2016 by Ayaka

Chemistry
H2S+Is >2HI+S
Saturday, April 16, 2016 by Science

Chemistry
What is the product for the following reaction: The reaction is a chair conformer of 1-methyl-1-cyclohexanol, with OH in the axial position and the methyl in the equatorial position, reacting with HCl. I'm wondering if this reaction is both SN1 and E1, and what are the E1 ...
Saturday, April 16, 2016 by April

Chemistry- Dr.Bob
A 40.0 mL sample of 0.100 M HNO2 is titrated with 0.200 M KOH. Calculate the pH at the equivalence point for the titration of HNO2 and KOH. When I did this problem again, I got pH= 8.08. Is this close to your answer? Dr.Bob: I estimated the pH and didn't come close to 11 ...
Saturday, April 16, 2016 by Nevaeh

Chemistry
A 40.0 mL sample of 0.100 M HNO2 is titrated with 0.200 M KOH. Calculate the pH at the equivalence point for the titration of HNO2 and KOH. I got pH= 11.74.
Saturday, April 16, 2016 by Nevaeh

Chemistry: Buffer Intensity problem
You wish to prepare a pH 4.76 acetic acid sodium acetate buffer with a buffer intensity of 1 M per pH. What concentrations of acetic acid and sodium acetate are needed?
Saturday, April 16, 2016 by Kaly

chemistry
Air bags in cars are inflated by the sudden decomposition of sodium azide (NaN3) by the following reaction. 2 NaN3(s) −→ 3 N2(g) + 2 Na(s) What volume of N2 gas, measured at 1.31 atm and 85.0◦C, would be produced by the reaction of 65.0 g of NaN3? Answer in ...
Friday, April 15, 2016 by abigail

chemistry
What volume of chlorine gas at 34.0◦C and 1.38 atm is needed to react completely with 9.40 g of sodium to form NaCl? Answer in units of L.
Friday, April 15, 2016 by abigail

Chemistry
Which is more soluble in water, Cl2 or I2?
Friday, April 15, 2016 by David

chemistry
how do i figure out the dilutions of 1.5L of a 15.0% (v/v) NaCl/water solution, what would the concentration of NaCl be if you added 3.0L of water
Friday, April 15, 2016 by sara

Chemistry
I'm not sure how to do these...I keep getting the wrong answers... Please help someone... Mg(s) + 2 HCl(aq)= MgCl2 (aq) + H2(g) a. What volume of 15.7 M hydrochloric acid will react with 2.1 grams of Mg? b. What mass of magnesium will react with 8.5 liters of 0.7 M ...
Friday, April 15, 2016 by Ava

Chemistry
Calculate the mass of NaCl required to cause dissolution of 0.010 moles of AgCl in 100 mL of solution. Consider that the addition of NaCl does not cause increased volume in the solution KSP (AgCl) = 1.0 x 10 ^ -10 KF (AgCl2) = 3.0 x 10 ^ 5 Answer This Question
Friday, April 15, 2016 by Monica

Chemistry
Calculate the mass of NaCl required to cause dissolution of 0.010 moles of AgCl in 100 mL of solution. Consider that the addition of NaCl does not cause increased volume in the solution KSP (AgCl) = 1.0 x 10 ^ -10 KF (AgCl2) = 3.0 x 10 ^ 5
Friday, April 15, 2016 by Monica

chemistry
1.20 L of a solution that is 15.0 % of Pb(NO3)2 by mass (the density of the solution is 1.16 g/mL), starting with solid solute. how would you prepare this?
Friday, April 15, 2016 by Anonymous

chemistry
A solution with a pH of 2.0 has a hydronium ion concentration ten times greater than a solution with a pH of?
Friday, April 15, 2016 by Anonymous

Chemistry
If it is known that the iron(ii) salt is FeSO4.7H20 calculate the %Fe from the formula
Friday, April 15, 2016 by Revash Singh

chemistry
0.4276-g sample of a potassium hydroxide – lithium hydroxide mixture requires 31.20 mL of 0.3315 M HCl for its titration to the equivalence point. What is the mass percent lithium hydroxide in this mixture? 1.) 0.03120 L x 0.3315= 0.010343 moles HCl I'm ...
Friday, April 15, 2016 by Tiff

chemistry
What is the volume of 3.11×10 to the power 23. Molecules of NH3 at S.T.P
Thursday, April 14, 2016 by deepak

Chemistry
Complete and balance these half-equations. Express as net ionic eqn. 1.) Cr2O7(2−) → Cr(3+) (acidic solution) So far, I have: Cr2O7(2−) + 14H + 6e(-) →2Cr(3+) + 7H20 2.) C2O4(2−) → CO2 (acidic solution) Not sure how to do this one. Thank you.
Thursday, April 14, 2016 by Daniel

Chemistry
How many grams of NO2 are needed to form 100.0g of HNO3?
Thursday, April 14, 2016 by Sharon

Chemistry
How many moles of O2 must react with 0.550 mole ofMethanol?
Thursday, April 14, 2016 by Sharon

Chemistry
How many grams of carbon dioxide ctsare produced when 78.0 grams of Methanol rea
Thursday, April 14, 2016 by Sharon

organic chemistry
what is this molecule called, a cyclohexane ring with a CH2 group coming off of it? C7H14 Similar in structure to a benzyllic radical without the pi bonds.
Thursday, April 14, 2016 by help me with naming

chemistry
Write and balance the equation for the reaction between nitric acid and potassium iodide. The products are potassium nitrate, iodine, nitrogen monoxide, and water. 2HNO3 + KI = KNO3 + I + 2NO + H2O (Did I write the equation correctly?)
Thursday, April 14, 2016 by Kat

Chemistry
A metal whose threshold frequency is 1.10×1015 s−1 emits an electron with a velocity of 6.53×105 m/s when radiation of 1.37×1015 s−1 strikes the metal. What is the mass of the electron?
Thursday, April 14, 2016 by Anonymous

Chemistry
How many (a) calcium ions and how many (b) nitride ions are there in 1.00 mol Ca3N2?
Thursday, April 14, 2016 by Arya

Chemistry
Find the % ionization if the pH of a 0.10 mol/L solution is 4.5
Thursday, April 14, 2016 by Korianna

Chemistry
Which must be the same when comparing 1 mol of oxygen gas, O2, with 1 mol of carbon monoxide gas, CO?
Thursday, April 14, 2016 by William

chemistry
Which of these elements has the electonic configuration of The energy absorbed or released when an electron is added to a gaseous atom is known as Which of these elements behave partly as an alkaline metal as well as a halogen element? Hydrogen can be obtained economically as ...
Thursday, April 14, 2016 by davids

Chemistry
Which reagent has been oxidized in the following equation ? H2(g) + N2(g) === NH3(g)
Thursday, April 14, 2016 by Feng

chemistry
given 0.0450 M ca(no3)2 and 0.0350 M fe(no3)2. when i separate them, which compound should be used? Na2co3(aq), Hcl(aq), or naoh(aq)? . and which will precipitate first? I went with hcl, and for question two, fe^2+
Thursday, April 14, 2016 by anonymous1

Chemistry
What is the molecular mass of a substance X if 1.00 L of a solution containing 4, 5 g of X has an osmolality of 0.337 mmHg the 30° C?
Thursday, April 14, 2016 by Caline

chemistry
When you add 0.567 g of sodium metal to an excess of hydrochloric acid, you find that 5890 J of heat are produced. What is the enthalpy of the reaction as written below? 2Na(s)+2HCl(aq)=2NaCl(aq)+H2(g)
Wednesday, April 13, 2016 by lex

chemistry
using leChatlier's principle, which of following is more or less soluble in following solutions than in pure water. and explaination for each asked for. Compared to pure water are they less, more or same? thanks. AgBr in 0.100M HBr AgBr IN 0.100 m HNO3 Fe(Oh)2 in 0.100 M ...
Wednesday, April 13, 2016 by anonymous1

Chemistry
Question Part Points Submissions Used It has been determined that the body can generate 5500 kJ of energy during one hour of strenuous exercise. Perspiration is the body's mechanism for eliminating this heat. How many liters of water would have to be evaporated through ...
Wednesday, April 13, 2016 by Tom

Chemistry
Describe how to make 100 mL of a 0.120 M solution of CU(NO3)2 * 3H20 (Making a solution lab)
Wednesday, April 13, 2016 by Roygbiv

Chemistry
For the reaction: 2NO(g) + H2(g) <=> N2O(g) + H2O(g) + energy Write the equilibrium constant expression for the reaction. I wrote: [N2O][H2O] / [NO]2 [H2] This reaction takes place at 25°C. At this temperature the concentration of NO is found to be 1.75 mol/L...
Wednesday, April 13, 2016 by Kat

chemistry
how many protons and electrons are in 7.4 grams of hydrogen?
Wednesday, April 13, 2016 by joe

Chemistry
If you have Mg+2HCL=MgCl2+H2 and a temp of 295K, and barometric pressure of .976atm and 43.5 mL of gas was collected from the experiment, then how many moles of H2 do you have? My answer is PV=nRT so n=PV/RT Plug in the numbers and get .00175 moles, but I think that's ...
Wednesday, April 13, 2016 by Kiana (Check My Answer Only)

Chemistry
A sample of g 0.2050 oxalic acid (4.2 H2C2O H2O) required 25.52 mL of KOH solution to complete the neutralization according to rea tion: HOOCCOOH + 2 KOH + KOOCCOOK ↔ H2O Which the concentration in mol L-1 of this KOH solution? A sample of an unknown oxalate 0.3025 g ...
Wednesday, April 13, 2016 by Michaela

Chemistry
On Mars, the gravitational acceleration (g) is equal to 3.7 m/s2. Imagine the experiment from our lab performed on Mars, using a distance of 68 m from the catapult to the bucket. What velocity would you need to launch the ball into the bucket?
Wednesday, April 13, 2016 by Denise

Chemistry
Which reagent has been oxidized in the following equation ? H2(g) + N2(g) === NH3(g)
Wednesday, April 13, 2016 by Feng

chemistry
1-What are the characteristics of the benzene molecule and those of the obtained product(1,2,3,4,5,6-hexachlorocyclo hexane). 2-The volume of used chlorine Cl when added to benzene is 240cm^3. What minimal volume of benzene is needed so that all of chlorine reacts? benzene ...
Wednesday, April 13, 2016 by angy

Chemistry
Sarah is ordering cheese pizza for a party of 10 people. She knows that each pizza has 8 slices. To figure out how many pizzas to order, Sarah needs to know the
Wednesday, April 13, 2016 by Katlen

chemistry
1-What are the characteristics of the benzene molecule and those of the obtained product(1,2,3,4,5,6-hexachlorocyclo hexane). 2-The volume of used chlorine Cl when added to benzene is 240cm^3. What minimal volume of benzene is needed so that all of chlorine reacts? benzene ...
Wednesday, April 13, 2016 by angy

Fundamental Chemistry
Given the balanced reaction below; write out the balanced ionic equation and the balanced net ionic equation. Include phase labels and charges where appropriate. Cu(s) + Zn(NO3)2 (aq) → Cu(NO3)2 (aq) + Zn(s)
Wednesday, April 13, 2016 by Dana

chemistry
calculate the lowest frequency of UV. light which has enough energy to break a Cl-Cl bond. ( bond energy =243kj/mol). I got 7.89E14 but the answer is 6.14E14s–¹​. how?
Wednesday, April 13, 2016 by jay

Chemistry
how would you prepare pure dry crystals of potassium trioxonitrate?
Wednesday, April 13, 2016 by Alexa

chemistry
From the enthalpies of reaction 2C(s)+O2(g)¨2CO(​g)ĢH=−221​.0kJ 2C(s)+O2(g)+4H2(g)Â&u​ml;2CH3OH(g)ĢH=​−402.4kJ calculate ĢH...
Tuesday, April 12, 2016 by ryno

chemistry
if 62.3 g of zinc react with hydrophosphoric acid (H3PO4) it produces zinc (I) phosphate and hydrogen. how much zinc (I) phosphate is produced?
Tuesday, April 12, 2016 by kim

Chemistry
Consider the following acid/base reaction CO3^2− + 2H^+ → H2O + CO2 that produces CO2 gas. 6 L of CO2 is collected at STP. What is the molarity of the HCl solution used in the reaction if 81 mL of HCl was needed?
Tuesday, April 12, 2016 by Claire

Chemistry
How do I calculate the heat released by 1 mole MgO Given: 0.5 g of MgO Heat gained by acid is 1337.6 kJ I calculated the moles for MgO which I got 0.0125 I'm not sure if I'm on the right track..
Tuesday, April 12, 2016 by Rose

Chemistry
You have a vinegar solution you believe to be 0.53 M. You are going to titrate 20.72 mL of it with a NaOH solution that you know to be 0.974 M. At what volume of added NaOH solution would you expect to see an end point?
Tuesday, April 12, 2016 by Claire

Chemistry
A 21.7 mL sample of 0.18 M KOH solution required 26.3 mL of aqueous acetic acid solu- tion in a titration experiment. Calculate the molarity of the acetic acid solution.
Tuesday, April 12, 2016 by Emma

Chemistry
The chemistry problem is "How would you make 500.0 mL of a 3.00 M HCl solution form a stock solution that is 6.00 M?" I have no clue how to even approach this problem.
Tuesday, April 12, 2016 by Nate

chemistry
Liquid methanol (CH 3 OH) is used as an alternative fuel in truck engines. When a 0.150 g sample of methanol was burned in a calorimeter, open to the atmosphere, the temperature increased 1.52 ºC. The heat capacity of the calorimeter was 1.97 kJ / ºC. ...
Tuesday, April 12, 2016 by jaspreet

chemistry
A sample of silicon absorbs 14.9 J of heat, upon which the temperature of the sample increases from 21.5°C to 28.5°C. If the specific heat of silicon is 0.710 J g -1 K -1 , what is the mass (in grams) of the sample?
Tuesday, April 12, 2016 by jaspreet

Chemistry 2
Potassium nitrate has a lattice energy of -163.8 kcal/mol and a heat of hydration of -155.5 kcal/mol. How much potassium nitrate has to dissolve in water to absorb 107 kJ of heat?
Tuesday, April 12, 2016 by kread561

  1. Pages:
  2. <<Prev
  3. 20
  4. 21
  5. 22
  6. 23
  7. 24
  8. 25
  9. 26
  10. 27
  11. 28
  12. 29
  13. 30
  14. 31
  15. 32
  16. 33
  17. 34
  18. Next>>

Homework Help: Science