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March 1, 2017

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

AP Chemistry!!!
If 5.6 g of aluminum at 65.2 °C is placed in a calorimeter that contains water at 23.5 °C and the temperature of the water after the heat exchange occurs is 24.7 °C, then identify how much water is in the calorimeter. I know this has something to do with q=mc delta T but I ...
Thursday, December 15, 2016 by Callie

Chemistry
A cube of solid reactant with sides of 1.00 cm² is submerged in a liquid and reacts to form a gas product at an initial rate of 20 mL/s. The solid-liquid interface is 6.0cm² of surface area. If you sliced this cube (like a block of cheese) into 10 slices, and then replaced ...
Thursday, December 15, 2016 by Anonymous

Chemistry
A gas is collected by water displacement at 25 degrees celsius.(the vapor pressure of water at that temperature is 24mmhg.if the atmospheric pressure is 800mmhg.what is pressure of the dry ice
Thursday, December 15, 2016 by Carol

chemistry
PLEASEEEE HELP Write the balanced equation for the reaction between zinc and acetic acid. The equation has been written you just have to balance. ___Zn + ___HC2H3O2 → ___Zn(CH3COO)2 + ___H2
Thursday, December 15, 2016 by Bre

Chemistry
What is the likely identity of a substance (see Table 10-1) if a sample has a mass of 16.0 g when measured in air and an apparent mass of 15.2 g when submerged in water? Which of the following is it? -copper -gold -lead -aluminum -iron or steal -concrete (Note: Can only select...
Thursday, December 15, 2016 by Dominick

chemistry
density of sand =3.00g/cm3?
Wednesday, December 14, 2016 by Anonymous

Chemistry
what happens when magnesium reacts with iodine to make magnesium iodide. Manymanymany thankyou's all round!!!!
Wednesday, December 14, 2016 by moi encore une fois!

Chemistry
what are atoms of nitrogen with different numbers of neutrons called?
Wednesday, December 14, 2016 by plz hlp asap!

Chemistry
what is the acid that is used to make ammonium nitrate???
Wednesday, December 14, 2016 by shannone

chemistry
what are atoms of nitrAogen with different numbers of neutrons called?
Wednesday, December 14, 2016 by Grande

Chemistry
A plasma reaction converts A (Molecular weight = 200) to B and uses NAD as a co-substrate and produces NADH as a by product (1 mole of NADH is produced per every 1 mole of A converted to B). The amount of NADH can be determined by monitoring its’ absorbance at 340nm in a ...
Wednesday, December 14, 2016 by Sophia

Chemistry
How much Zn is mixed with 2HCl = ZnCl + H2 ?
Tuesday, December 13, 2016 by Joe

Chemistry
What group of elements were not on the original periodic table
Tuesday, December 13, 2016 by Anonymous

AP Chemistry!!!
Explain the reaction that would occur in a galvanic cell between solutions of Al3+ and Pb2+. Identify the oxidation and reduction reactions and the location of each reaction. Then, use the standard reduction potential tables to determine the cell potential.
Tuesday, December 13, 2016 by Callie

Chemistry
Show calculations (labeled with units) needed to prepare 25 mL of 0.20 M Pb(NO3)2 and 25 mL of 0.20 M NaI.
Tuesday, December 13, 2016 by Jeb

Chemistry (PLZ HELP)
Aluminium can be produced by the thermal decomposition of aluminium oxide. What mass of aluminium would be produced from 3.5kg of aluminium oxide?
Tuesday, December 13, 2016 by Anonymous

Chemistry
Determine the volume of a 0.1 M solution of HCl, necessary to titrate 20 mL of a 0.5 M solution of NH3. The value of Kb is 1.8 x 10-5.
Tuesday, December 13, 2016 by Melanie

Chemistry
Determine the variation of the buffer of the problem 1, if 200 mL of the buffer is added 10 mL of a 1.0 M solution of HCl.
Tuesday, December 13, 2016 by Melanie

Chemistry
Calculate the pH of a buffer made of a 0.4 M of acetic acid and 0.5M of sodium acetate. The Ka for the acetic acid is 1.8 x 10-5.
Tuesday, December 13, 2016 by Melanie

chemistry
1. Silicon dioxide reacts with carbon upon heating to produce silicon carbide (SiC) and carbon monoxide. SiO2(s) + 3C(s) = SiC(s) + 2CO(g) a. What mass of carbon is required to react completely with 15.70 g of SiO2? b. When 152 g of SiO2 reacts with excess carbon, what mass of...
Tuesday, December 13, 2016 by Luke

chemistry
A hydrochloric acid So of concentration 1mol/l and a solution S1 of concentration C1= 2×10^-2 mol/l to be prepared from So. The available materials are given below: ● Volumetric pipet: 5ml, 10ml, 20ml ● Beakers: 100ml, 250ml, 500ml ● volumetric flask : 100ml, 500ml ● ...
Tuesday, December 13, 2016 by angy

physics biology chemistry and ict
WHAT ARE THE ALLOTROPES OF ANTIMONY
Tuesday, December 13, 2016 by SEINI OUSMAN

Chemistry (just need someone to check my answer)
When iron metal reacts with oxygen, the reaction can form Fe2O3. Write a balanced chemical equation for this reaction, and find the number of moles of oxygen that are needed to form 6 mol of Fe2O3. My answer: 9 moles of oxygen
Tuesday, December 13, 2016 by Zoella

chemistry
The first order rate constant for the decomposition of N2O2 of 0Cis 5.2*10/6 per minute. If the activation energy is 6200J/mol, calculate the rate constant at 25C
Tuesday, December 13, 2016 by hadiza

Chemistry
Hello, I was wondering what would happen if u add KOH(potassium hydroxide) solution instead of KOH solid to HCL (hydrochloric acid). Currently, learning enthalpy in class and I'm not sure how this affects enthalpy
Monday, December 12, 2016 by Ann

AP Chemistry
Tungsten(VI) oxide can be reduced to tungsten by heating it with carbo, as shown in the reaction: 2WO3(s) + 3C(s) <---> 2W(s) + 3CO2(g) If the original mass of WO3 is 37.0 g, how many grams of CO2 must be collected from the reaction in order to infer that the solid that ...
Monday, December 12, 2016 by Landon

Chemistry
What is the total ionic and net ionic equation for this aqueous reaction?: Sr(OH)2(aq) + HClO2 (aq) -I wrote the molecular as: Sr(OH)2 (aq) + HClO2 (aq) ---> SrClO2 (aq) + H20 (l) -Is the Total Ionic: Sr2+ (aq) + 2OH- (aq) + H+ (aq) + 2ClO- (aq) ---> Sr2+ (aq) + 2ClO-(aq...
Monday, December 12, 2016 by Les

Chemistry
How many aluminum atoms are there in 15.0mg of Al2O3?
Monday, December 12, 2016 by Les

chemistry
What is the ∆G for the following reaction under standard conditions (T = 298 K) for the formation of NH4NO3(s)?
Monday, December 12, 2016 by abraham

Chemistry
Find the Percentage Composition of 0.68g of CaCO3 in 1.3g of antacid tablet. I think it is 680/1300*=approx. 52%
Monday, December 12, 2016 by Akshay

Chemistry
What is the total number of mole of atoms in 1 mole of Al2(CO3)3?
Monday, December 12, 2016 by Pedro

Chemistry
What is the concentration of Pb in mg/L , if you have 25 mg Pb in 5kg of seawater? (note: density of seawater is 1.025 kg/L)
Monday, December 12, 2016 by Sam

Chemistry
Using the fact that fresh water has a density of 1000 kg/m3 , show that 5ppm Pb = 5 mg/L Pb .
Monday, December 12, 2016 by Sam

Organic Chemistry
Hello! I was looking for some advice on my organic chemistry lab. We were supposed to separate and identify a solid mixed into a liquid. I found and have confirmed my liquid is acetone by distilling it out of the solid. The solid then turned into a whitish powder while in the ...
Monday, December 12, 2016 by Abby

Chemistry
rank the compounds below in order of increasing vapor pressure at 298 K? A) c3h6 B) c4h8 C) c5h10
Monday, December 12, 2016 by Vanessa

Chemistry
If an astronaut weights 804n on earth what would he weight on a planet that has 3 times the mass and twice the radius of earth
Monday, December 12, 2016 by William

Chemistry (percent abundance) *emergency*
If the average atomic mass of Br is 79.90 amu, what is the percent abundance of each of its isotopes? How would we figure out the isotopes first before we calculate the percent abundance??
Monday, December 12, 2016 by Ray

Chemistry
4Fe + 3O2 = 2Fe2O3 158g of Fe will react with how many litres of O2 to produce the maximum amount of Fe2O3
Sunday, December 11, 2016 by Ethan

Chemistry
A 50.0 mL aqueous solution of sodium hydroxide has a pH of 12.50. If 36.00 ml of 0.0200 mol/L sulfuric acid is added to this sodium hydroxide solution, what will be the new pH of the resulting solution? Assume that the temperature stays constant at 25 C, and that the volumes ...
Sunday, December 11, 2016 by Jacob

Chemistry
If 8.87 g of CuNO3 is dissolved in water to make a 0.500 M solution, what is the volume of the solution?
Sunday, December 11, 2016 by Dalton Steele

Chemistry
Why do carbonated beverages go "flat" when opened and left and room temperature and pressure?
Sunday, December 11, 2016 by Anonymous

Chemistry (PLZ HELP)
State why you think clothes might be important to clean in hot water. Is it because it has to do with solubility or something?
Sunday, December 11, 2016 by Anonymous

chemistry
Hydrochloric acid solution reacts with zinc according to the following equation: 2H3O + Zn -> Zn^2+ + H2 +2H2O 100ml of hydrochloric acid solution Ca=0.5mol/l must be prepared from C=5mol/l hydrochloric solution. 1) Specify the glassware needed for this preparation . At ...
Sunday, December 11, 2016 by angy

Chemistry
Draw the Lewis Structure of CH3NCS including all resonance forms. Assign formal charges. Do not include resonance arrows.
Sunday, December 11, 2016 by Raeann

chemistry
What volume of 0.900 M HCl is required to complete neutralize 50.0 ml of a 0.500 M Ba(OH)2 solution?
Sunday, December 11, 2016 by Subiza

Chemistry
This same substance is a gas with a density of 1.25 g/L at 127o C and a pressure of 400 torr. What is its molar mass ?
Sunday, December 11, 2016 by KC

Chemistry
Ammonium nitrate is an oxidizing agent and can give rise to explosive mixtures of mixture of two moles of powdered aluminum and 3 moles of ammonium nitrate crystals react exothermically yielding nitrogen gas water vapor and aluminum oxide how many grams of the mixture are ...
Sunday, December 11, 2016 by Cindy

chemistry
what is the procedure for the preparation of 10 gram of lead iodide
Sunday, December 11, 2016 by kanniga

Chemistry
A scintillation counter detects radioactivity by: A) none of the answers. B) emission of light from a NaI crystal when radioactivity passes through the crystal. C) ionization of argon gas in a chamber which produces an electrical signal. D) analyzing the mass and velocity of ...
Sunday, December 11, 2016 by Mimi

Chemistry
For the reaction Ag2S(s) ⇌ 2 Ag+ (aq) + S2- (aq), what happens to the equilibrium position if ammonium sulfate is added? A) doubles B) shifts to the left C) does nothing D) shifts to the right E) halves
Saturday, December 10, 2016 by Mimi

chemistry
how many grams of sodium hydroxide is required to neutralize 73grams of hydrochloric acid and to form sodium chloride and water
Saturday, December 10, 2016 by bala

chemistry
The edge of a body-centered-cubic unit cell ( which contains two atoms per unit cell) of an element Y was found to be 2.16x10^-8cm. The density of the metal is 19.35g*cm^-3. What is the approximate molar mass of Y?
Saturday, December 10, 2016 by John

Chemistry
I just need someone to check my answers please :) On the pH scale are the following items base, neutral, or acid? 1. Hand Soap 2. Blood 3. Milk 4. Coffee 5. Orange Juice 6. Soda Pop 7. Vomit 8. Battery Acid My answers: 1. Base 2. Neutral 3. Neutral 4. Neutral 5. Base 6. Acid 7...
Saturday, December 10, 2016 by Zoella

Chemistry
a+b<->c (fast) c+d->e (slow) e->f+b (fast) How do you determine the overall equation for these reaction mechanisms?
Saturday, December 10, 2016 by Neil

Chemistry
Write a chemical equation for 48g of gasoeous hydrogen and 320g of gaseous oxygen yield
Saturday, December 10, 2016 by Help

chemistry
Industrial waste contains Zn(II) and cyanide. The waste is toxic to aquatic species like fish. 1- If the waste consists of water, Zn(II) and cyanide, what ligands might complex with Zn(II)? 2- Write chemical equilibria reactions the must be considered to determine toxicity of ...
Saturday, December 10, 2016 by Alex

Chemistry
Identify the equation for which Keq = [Cu+]2[S2-]. A) CuS(s) ⇌ Cu2+(aq) + S2- (aq) B) 1/2Cu2S(s) ⇌ Cu+(aq) + 1/2 S2- (aq) C) Cu2S(s) ⇌ 2Cu+(aq) + S2- (aq) D) Cu2S(s) ⇌ Cu+(aq) + 2 S2- (aq) E) none of the answers
Saturday, December 10, 2016 by Mimi

Chemistry
Which of the following is TRUE for a system that is in dynamic equilibrium? A) The forward reaction goes to 100% completion. B) The concentration of products is equal to the concentration of the reactants. C) The reaction rate of the forward reaction approaches zero. D) Both ...
Saturday, December 10, 2016 by Mimi

Chemistry
for any solute what important condition must be stated in order to report the solubility answer
Saturday, December 10, 2016 by Angelina

Chemistry
Calculate partial pressure given ka1, pH and KH The equation given in the question was: HCO3-(aq)+H3O+(aq)= CO2(aq)+H2O Calculate the partial pressure of CO2. I think you use : [H3O+] = ka1x(antilog pH)/(antilog pH) Then Henrys law: Equilibrium conc.[G]=Kh(law constant) × pg...
Saturday, December 10, 2016 by Seth

Chemistry
Hi , I have this question and I do not know what steps to follow. Please help guide me. It will be really appreciated. Calculate the extent of oxidation in a stream where water it's in equilibrium with atmospheric oxygen and had a pH pic 6.5 (a(H3O+) =antilog (-6.5) ). The ...
Saturday, December 10, 2016 by Sarah

CHEMISTRY
what volume of hydrogen is produced with excess HCL according to the equation Zn+2HCL-ZnCL2+H2
Saturday, December 10, 2016 by FEMI

chemistry
The edge of a body-centered -cubic unit cell (which contains two atoms per unit cell) of an element Y was found to be 3.16x10^-8cm.The density of the metalis 19.35g*cm^-3. What is the approximate molar mass of Y?
Saturday, December 10, 2016 by John

Chemistry
Consider two equally sized balloons at room temperature, one filled with oxygen gas and one filled with an unknown gas. If the balloon filled with oxygen gas deflates in 37 hours and the other balloon deflates in 26 hours, which of the following is the most likely identity of ...
Saturday, December 10, 2016 by bill

Chemistry
If 2.00 g of element G reacts with 5.00 g of element M to produce 7.00 g of a compound with the formula G3M2, what is the atomic mass of G if the atomic mass of M is 135.0 amu? Answer is 36 amu but why
Friday, December 9, 2016 by bill

Chemistry
I am using 85% ACS grade phosphoric acid. I need to make a 21% phosphoric acid solution with a total volume of 250ml. I have been told that 37ml of the 85% ACS grade phosphoric acid plus 188ml of Deionized water will create the 21% phosphoric acid solution I need to make. I'm ...
Friday, December 9, 2016 by Melissa

chemistry
Explain how sodium carbonate can be used to soften hard water
Friday, December 9, 2016 by alphaticus

Chemistry
Phosphate can act as buffer: H2PO4- HPO4^2- + H+ The pKa of this equilibrium is 7.21. What is the ratio of H2PO4- to HPO4^2- at pH 7.0? A. 1.62 B. 0.62 C. 50.47 D. 0.019 E. 0.21
Friday, December 9, 2016 by Uurka

chemistry
Please help: How do you prepare 2 L of formate buffer pH=3.14 (c=0.05mol/l) (pk=3.74). THEY WANT THE VOLUMES THANKS
Friday, December 9, 2016 by stavr65

chemistry
A serving of cereal contains 90mg potassium. If there are 22 servings in a box how many moles of Potassium are present in the cereal in the box
Friday, December 9, 2016 by lashell

chemistry
How many moles of sugar are contained in a 10lb bag of sugar if the sugar has the formula C12H22O11
Friday, December 9, 2016 by lashell

Chemistry
A is a solution of tetraoxosulphate(iv)acid.B contains 3.95g of sodium trioxocarbonate(iv) in 750cm3 of solution.if 22.70cm3 of the tetraoxosulphate(iv)acid neutralized 25.0cm3 of sodiumtrioxocarbonate(iv).calculate the concentration of i) B in moldm-3 ii) A in moldm-3
Thursday, December 8, 2016 by Yvonne

chemistry
how many moles are released when 13.2 g of ammonium sulfate 2NH4SO4 is dissolved in water ? I know 13.2 g 2NH4SO4 = .099 moles
Thursday, December 8, 2016 by David

chemistry ksp
i feel like none of these answers are right. if the solubility of the solid is 'S' mol/ L, what is the Ksp of the product of the salt? Ca3PO42-(s) --> 3Ca2+(aq) + 2PO42- (aq) A)ksp=S^2 B)ksp=4S^3 C)ksp=27S^4 D)ksp=108S^5 Only leaning towards D because its the only one that ...
Thursday, December 8, 2016 by Anonymous

chemistry
how do you calculate the equilibrium constant K for a reaction given only the equilibruim pressure for the sample...i thought u needed partial pressures for all substances involved. They just tell me the eq pressure is 3 atm for the sample and ask for Keq. Here's the rxn... ...
Thursday, December 8, 2016 by Anonymous

AP Chemistry
For the reaction cyclopropane(g) → propene(g) at 500◦C, a plot of ln[cyclopropane] vs t gives a straight line with a slope of −0.00067 s−1 . What is the order of this reaction and what is the rate constant?
Thursday, December 8, 2016 by Virginia

Chemistry
1.prepare 2L of 0.150 deci normal aluminum chloride 2.saline solution contains 2grams of its major constituent solute in 1000ml of water.what is it's normality
Thursday, December 8, 2016 by Esther

Chemistry
Equal volume of 3 acids solution with pH 3,4,5 are mixed in a vessel. What will be the hydrogen ion concentration in the mixture ?
Thursday, December 8, 2016 by Anindita

Chemistry
The concentration of hydrogen ion in a sample of soft drink is 3.8×10^-3M. Calculate it's pH.
Thursday, December 8, 2016 by Anindita

chemistry
Moles chemistry? Calculate the mass of solute required to prepare ib the solution 200cm^3 of solution containig 0.50 mol dm ^-3 cl-iond prepared by dissolving cacl2.6h2o in water.
Thursday, December 8, 2016 by joanna

chemistry
Find the number of moles in 12×10^24 CO2 molecules 1mole is equal to 6.0×10 ^23 ? 12x10^24 Then division of them but the answrr did not match the answer of the book
Thursday, December 8, 2016 by joanna

chemistry
300 milimole of perfect gas occupies 13 lit at 320 k ,calculate the work done in joule ,when the gasexpands A)isothermally against a constant pressure of .20 atm Isothermal and reversible process c)Into vaccum until volume of gas is increased by 3 ltr
Thursday, December 8, 2016 by Dhruvi

Chemistry
1.63 L of an aqueous solution containing 25.00g of KCl dissolved in pure water is prepared. The molarity of the solution is?
Thursday, December 8, 2016 by Zyler

Chemistry
The mass of silver produced by thermal decomposition of 5.52g Ag2CO3
Thursday, December 8, 2016 by Naveen

chemistry
How many grams of water and how many grams of 85 wt% phosphoric acid would be needed to make 100 grams of 37 wt% phosphoric acid solution?
Wednesday, December 7, 2016 by Anonymous

Chemistry
what is the lowest frequency photon that can ionize a hydrogen atom with excited state electron configuration 3s1
Wednesday, December 7, 2016 by Joshua

Chemistry
electrons are ejected when a metal is irradiated with 570 nm light. if the wavelength of the ejected electrons is 1.0 nm, what is the work function of the metal? The answer is 1.08 X 10^-19 J, but I dont know how to get here
Wednesday, December 7, 2016 by Joshua

chemistry
ogen and oxygen react to form nitrous oxide as: 2 N2 (g) + O2 (g) ⇌ 2 N2O (g) Of a mixture of 0.482 mol N2 and 0.933 mol O2 is placed in a reaction vessel of 10.0 L and allowed to from N2O at a temperature for which Kc = 2.0 X 10-37, what will be the composition of the ...
Wednesday, December 7, 2016 by Marwan

chemistry
A bottle of commercial hydrochloric acid solution So is labeled 37% composition by mass, density 1.19 kg/L. Calculate the concentration of solution So. 4.2 ml of So are diluted to 500ml solution called S. We titrate S with 200 ml of KOH solution of 3×10^-3 mol/l placed in a ...
Wednesday, December 7, 2016 by angy

Chemistry
Draw and repeat unit for a reaction product of glycol: HO-CH2-CH2-CH2-CH2-OH with the following carboxylic acid: HO-C-CH2-CH2-C-OH = = O O
Wednesday, December 7, 2016 by Anonymous

Chemistry
A certain substance has a heat of vaporization of 62.08 kJ/mol. At what Kelvin temperature will the vapor pressure be 4.50 times higher than it was at 361 K? I've gotten it to the point of: ln(4.50)=7466.47423176378616 K (1/361 - 1/T2) Solving for T2 but I don't know where to ...
Wednesday, December 7, 2016 by Anonymous

Chemistry
I just need some ideas of what to put for these on my homework examples for extra credit Name a molecule that has: A) Tetrahedral Geometry B) Trigonal planar geometry C) Linear Geometry D) Bent Geometry
Wednesday, December 7, 2016 by Anonymous

Chemistry
What is tha process of balancing a chemical equation by partial equation method?
Wednesday, December 7, 2016 by Brajesh kumar

Chemistry
You are given 1.226 g of a mixture of KClO3 and KCl. When heated, the KClO3 decomposes to KCl and O2, 2 KClO3 (s) → 2 KCl (s) + 3 O2 (g), and 246 mL of O2 is collected over water at 24 °C. The total pressure of the gases in the collection flask is 755 torr. What is the ...
Wednesday, December 7, 2016 by Ash

pmt coching chemistry
25 ml of 3M hno3 are mixed with 75ml of 4.0M HNO3 if volumes are additive then find molarity
Wednesday, December 7, 2016 by sanju kurmi

Chemistry
What is the ionic compound of SrMnO4
Tuesday, December 6, 2016 by Jhoceline

Chemistry
The volume of a sample of a gas collected over water at 32 Celsius and 752 torr is 627 ml. What will the volume of the gas be when dried and measured at STP? (Vapor pressure of water at 32 Celsius = 35.7 torr)
Tuesday, December 6, 2016 by Ken

Chemistry
Calculate the new concentration of NaOH if 35 mL of 2.0M NaOH is added to 45 mL of water. If I don't use C1V1=C2V2, then how do I solve it? I'm confuused.
Tuesday, December 6, 2016 by Nissa

Chemistry
How many milliliters of 2.3 M NaOH are needed to neutralize 4.2 mL of a 5.4 M H2SO4 solution?
Tuesday, December 6, 2016 by Ian

chemistry
In a calorimetry experiment, 2.14 g of NH4Cl is dissolved in 100.0 mL of water. The temperature drops by 1.43°C. Calculate the molar heat of solution for NH4Cl.
Tuesday, December 6, 2016 by Anonymous

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