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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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?

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

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 ?

Chemistry
The concentration of hydrogen ion in a sample of soft drink is 3.8×10^-3M. Calculate it's pH.

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.

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

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

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?

Chemistry
The mass of silver produced by thermal decomposition of 5.52g Ag2CO3

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?

Chemistry
what is the lowest frequency photon that can ionize a hydrogen atom with excited state electron configuration 3s1

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

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 ...

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 ...

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

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 ...

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

Chemistry
What is tha process of balancing a chemical equation by partial equation method?

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 ...

pmt coching chemistry
25 ml of 3M hno3 are mixed with 75ml of 4.0M HNO3 if volumes are additive then find molarity

Chemistry
What is the ionic compound of SrMnO4

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)

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.

Chemistry
How many milliliters of 2.3 M NaOH are needed to neutralize 4.2 mL of a 5.4 M H2SO4 solution?

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.

Chemistry
7.0 mL of 0.64 M HBr reacts with 38 mL of 0.39 M KOH. 1) What are the moles of acid before the reaction? 2) What are the moles of base before the reaction? 3) What is the limiting reagent? 4) How many moles of excess reagent are there after the reaction? 5) what is the ...

Chemistry Help
You are required to make 500 mL of a buffer solution with pH = 5.0 and a total acetate concentration of 0.1000 M. You are supplied with solid sodium actetate (CH3COONa) and 2.00 M hydrochloric acid. What mass of sodium acetate and what volume of hydrochloric acid would you use...

Chemistry
Okay so my lecturer has this in our slides and there are no notes just a heading saying speaciation, I have tried google and everything I have read does not include pH in their question. Please help me Calculate the equilibrium concentrations of the different species in a 0....

Chemistry-Help Please
Help please. Am doing a past exam paper and I hit a road block with this question: Chloride in a brine solution is determined by a precipitation titration. A 10.00 mL aliquot of the solution is titrated with 15.00mL of standard 0.1182 M AgNO3 solution. The excess silver is ...

Chemistry (identifying equations)
What type of reactions are these? Acid-base? Oxidation/Reduction? Precipitation? 1) Zn (s) + 2 HCl (aq) -> ZnCl2 (aq) + H2 (g) 2) Fe (s) + CuSO4 (aq) -> FeSO4 (aq) + Cu (s) 3) Fe (s) + Cu(NO)2 (aq) -> Fe(NO3)2 (aq) + Cu(s)

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

chemistry
find the mass of silver chloride formed from 33.2ml of a 0.100M solution of silver nitrate and 200ml of 0.200M solution of calcium chloride solution Solution plan:use mass to mass calculations mass of AgNO3-moles of AgNO3-moles of AgCl-mass of AgCl 0.1mol/1L*0.0332L+0.200mol/...

chemistry
how does H-bonding affect freezing point depression? I did a lab and calculated my exp molecular weight for benzoic acid and i got a value that is double the known value. My prof said it is due to H-bonding...i don't understand what effect it has on the MW...

Chemistry
Suppose you titrated a sample of sulfuric acid (diprotic acid) with a 0.250 M solution of NaOH. Given the data in the table below, what is the concentration of the sulfuric acid solution?

Chemistry
Calculate the total pressure above 1.0L solution of a 1.42M CH3OH(aq) solution at 25 degrees(C). The vapor pressure of pure methanol at 25 degrees (C) is 127.1 torr and the vapor pressure of the pure water is 23.8 torr at 25 degrees(C. You may assume that the density of the ...

Chemistry
What is the vapor pressure of a solution prepares by dissolving 4.25g of K2O in enough water to preapare 1.25L of Solution at 25 degrees (C)? Assume that the density of the solution is 1.00 g/mL and that the vapor pressure of pure water is 23.8 torr at 25 degrees (C). I've ...

Chemistry
Help please. Am doing a past exam paper and I hit a road block with this question: Chloride in a brine solution is determined by a precipitation titration. A 10.00 mL aliquot of the solution is titrated with 15.00mL of standard 0.1182 M AgNO3 solution. The excess silver is ...

chemistry chem check
Two liquids, 'R' and 'S' form an ideal mixture, what is true about the relation between the mole fraction of R in the liquid phase (X_r) and that of the vapor phase (Y_r) for most mole fractions in the range of 0<X_r<1. A)X_r < Y_r B) X_r > Y_r C)X_r = Y_r D) X_r +...

Chemistry
Calcium carbonate reacts with HCl according to the following equation: 2HCl(aq)+CaCO3(s)→CaCl2(aq)+H2O(l)+CO2​(g) How many moles of HCl are in 58 mL of 0.13 M HCl? What mass of calcium carbonate is needed for complete reaction with the HCl in (a)?

Chemistry
Consider the reaction: Fe2O3+2Al=Al2O3 How many kg of Al2O3 are produced from 25.2 kg of Fe2O3 assuming there is sufficient Al?

Chemistry
Consider the reaction: Fe2O3+2Al=Al2O3 How many grams of Al are necessary to make 100.2 grams of Al2O3?

Chemistry
Consider the reaction: Fe2O3+2Al=Al2O3 How many grams of Fe2O3 Are necessary ro make 100.2 grams of Al2O3? Step by step please.

chemistry
What is the seperation energy ineV for Be3+ in the first excited state in eV?

Chemistry
If a 30.pL tank of laughing gas contains 2.74 moles of N2O at 25 degrees C, what is the pressure (atm) in the tank?

Chemistry
How do orbitals on individual atoms interact and change when covalent bonds form in molecules?

Chemistry (equlibrium direction) urgent
Consider the endothermic reaction 2 NO(g) <-> N2(g) + O2(g) -If I decrease the volume of the vessel and increasing the total pressure in the vessel, what direction will the equilibrium will shift? (left/right) (I know that decreasing the volume would shift to produce ...

Chemistry
A recipe calls for 5M of sucrose (C12H22O11) dissolved in 750mL of H2O. Please calculate the total mass (g) of sucrose needed. Show all work.

chemistry
A major component of gasoline is octane (C8H18). When octane is burned in air it chemically reacts with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O). What mass of oxygen gas is consumed by the reaction of 8.17g of octane?.

chemistry
illustrate how to prepare a 1:3 solution of 0.5 hydrochloric acid

Chemistry
A solution is made by dissolving 55g of KCl in enough water to make 1.00 L of solution. Assume that the density of the solution is 1.00 g/mol. Calculate the mass percent, molarity, molality, and mole fraction of KCl.

chemistry
calculate the mass of butane needed to produce 79.7g of carbon dioxide. express your answer to three significant figures and include the apprppriate units

Chemistry
A Starbucks Venti Caramel Macchiato contains about 42.0 grams of sugar. If we assume all the sugar is in the form of sucrose, use your answer from Question 4 to determine how many nutritional calories are produced in burning this quantity of sugar. Give your answer as a ...

Chemistry
Table sugar consists primarily of sucrose, C12H22O11(s). The standard enthalpy of combustion for sucrose is the ΔHo for the reaction: C12H22O11(s) + 12 O2(g) → 12 CO2(g) + 11 H2O(l) Calculate this ΔHo. Give your answer in units of kJ to five significant figures. Use the ...

Chemistry
Magnesium metal reacts with HCl(aq) according to the equation: Mg(s) + 2 HCl(aq) → MgCl2(aq) + H2(g) In an experiment to determine the ΔH for this reaction, 0.158 g of Mg metal is combined with an excess of HCl to make 100.0 mL of solution in a coffee cup calorimeter. Upon ...

Chemistry
Table sugar consists mostly of sucrose, C12H22O11. The standard enthalpy of combustion for sucrose is the standard state delta H for the reaction: C12H22O11 + 12 O 2 ---> 12 CO2 + 11 H2O Calculate this standard state delta H. Give answer in units of kJ to five significant ...

Chemistry
Mg + 2HCI --> MgCl2 + H2 0.158 g of Mg metal is combined with an excess of HCl to make 100.0 ml of solution in a coffee up calorimeter. The reaction rises from 25.60 C to 32.80 C. Determine delta H for the reaction of one mole of Mg. Units in kJ. 3 significant figures.

chemistry
how many grams of NaOh are needed to make 50 g of Na3PO4 according to the equation: 3NaOH+H3PO4=Na3PO4+3H2O (i'm not sure where to even start for this!)

Chemistry (molarity) *emergency*
Hi there, maybe dumb question but how would I find the initial concentration of Fe^3+?? In lab, we mixed these reactants into one test tube: -0.50mL of 0.0025M Fe(NO3)3 -0.50mL of 0.0025M KSCN -2.50mL of 0.10M HNO3 The net ionic equation for the experiment is: Fe^3+(aq) + SCN...

chemistry
Fe2+ is oxidized to Fe3+ and CrO4is reduced to Cr3+ using an unknown sample containing Fe2+ and 0.04322M K2CrO4 solution in a redox titration. I first need to balance the formula, but I don't know what to do with the potassium.

chemistry
how many grams of NaOh are needed to make 50 g of Na3PO4 according to the equation: 3NaOH+H3PO4=Na3PO4+3H2O (i'm not sure where to even start for this!)

chemistry
2C2H6 + 7O2 --> 4CO2 + 6H20 given 7.5 X 10 to the 3rd of C2H6 how many grams of CO2 is emitted the 7.5 x 10 to the third is 7500 what do i do to figure out the rest

chemistry
Nitric acid can be produced by the reaction of gaseous nitrogen dioxide with water. 3 NO2(g) + H2O(ℓ) −→ 2 HNO3(ℓ) + NO(g) If 900 L of NO2 gas react with water, what volume of NO gas will be produced? Assume the gases are measured under the same conditions. Answer in L.

Chemistry
What mass of carbon dioxide is produced when 7.5g of methane is completely burnt in air.

chemistry
What is the mass of 3.22mol of ethane

chemistry
Arrange the following in the increasing order of boiling point 1.ch3br 2.ch3cl.3.chbr3.4.ch2cl2

Chemistry
How would you prepare 2.15 L of a 8.00 M solution from a 12.0 M stock solution?

Organic chemistry
How would I draw the structure for (3e,5z)-6-bromo-3-fluoro-3,5-nonadiene? I drew out the main chain of 9 C's, fluoride on 3, double bond between 3 and 4, double bond between 5 and 6, bromide extending out from 6. I understanding E is Trans (priorities opposite) and Z is cis (...

Chemistry
can you help me define a buffer and explain how a buffer

chemistry chem check
an ideal mixture contains 0.4 mol of nonvolatile solute and 0.8 mol of volatile solvent. the resulting vapor pressure was 60 mmHg at 300K. What vapor pressure should be reported at 300 K for pure solvent? A) 48 mmHg B) 60 mmHg C) 75 mmHg D) 90 mmHg **Would it be B) 60 mmHg ...

chemistry
how much mass of chlorine would be needed to make 73 tonnes of hydrogen chloride

Chemistry
8.1g of XSO4.7H2O crystal when heated at 90degree for 15 minutes gave 6.9g of the salt,which gave 4.9g when heated further at 120degree. If X is 72. Calculate the amount of water of crystallization in the intermediate and final salts. [X=72,S=32,O=16,H=1]

Chemistry
How many mL of 0.100 M NaOH are required to neutralize (or titrate) 25.0 mL of 0.15 M H3PO4?

chemistry
Arrange the following in decreasing order of their massess . a. 2.5 moles of water. b. 3.012×10×24 c. 25 g of water

SCIENCE-CHEMISTRY
Find the mass (kg) of a metallic block in the form of a cube 30cm on the side,if its density is 5.6kg/L.

Chemistry
1)A solution prepared by adding 0.400 mol of acetic acid (pKa = 4.74) and 0.400 mol of sodium acetate to 100.0 mL of water. The pH of this buffer solution is initially 4.74. Predict the final pH when 55.0 mL of 1.10 M NaOH is added to solution 2) A solution prepared by adding ...

Chemistry
1)A solution prepared by adding 0.400 mol of acetic acid (pKa = 4.74) and 0.400 mol of sodium acetate to 100.0 mL of water. The pH of this buffer solution is initially 4.74. Predict the final pH when 55.0 mL of 1.10 M NaOH is added to solution 2) A solution prepared by adding ...

Chemistry
When ammonia was reacted to copper(ll)oxide at a high temperature, it will produce nitrogen gas, copper metal and water vapour. an experiment was done with 18.0g of ammonia was reacted with 90.0g of copper(ll)oxide. (a)Write balance chemical equations for this reaction. (b)...

chemistry
Derived the equation pH = pKa + Log [base] for a weak acid and its conjugate base, [acid]

chemistry
Tell how you would prepare an acetic acid/acetate buffer solution having apH of 3.79. Ka for acetic acid = 1.85 x 10-5

Chemistry 30
How to find Oxidation Numbers of any component

chemistry
9.25% KCl solution is prepared by dissolving enough of the salt to give 100.0 g of solution. What is the mass of water required?

Chemistry
Ch3-ch2-c'ch3,ch2'ch3-ch2-ch3

Chemistry
calculate the volume needed to make 2.20 x 10^2 ml of 0.100M cacl2. what would be the total concentration of the final (Cl-) alone?

Science chemistry please help
Determine the number of moles of oxygen in 1 mol of dinitrogen tetraoxide

Science chemistry
Determine the number of moles of oxygen in 1 mol of dinitrogen tetraoxide N2O4= N 2×14.01g/mol= 28.02g/mol O 4×16.00g/mol= 64.00g/mol N2O4= 92.02g/mol I can't get the right formula to solve the rest. Please help and thank you

Chemistry
Arrange the following from LOWEST to HIGHEST number of particles per L of solution: .1m Na3PO4 .1m C2H5OH .01m CO2 .15m NaCL .2m CaCl2

Chemistry
one mole of ethanol releases 326.7 calories of energy during combustion. how many calories kilojoules are released? thank you ! :)

Chemistry
Answer the questions about the following reaction. 4Al(s) + 3O2(g) 2Al2O3 (s) How many molecules of O2 are used in the reaction? How many oxygen atoms are required? How many moles of Al2O3 are formed? What is the mole ratio of Al to O2?

Chemistry
Calculate the equilibrium constant 2SO2(g]+O2(g]⇌2SO3(g] given equilibrium constant of SO2,O2,SO3 are 0.3m,0.14,1.45 respectively wt happens to the equilibrium constant a) if so2 is added b)if o2 is removed

Chemistry
2SO2(g]+O2(g]⇌2SO3(g] ,4 conditions by which concentration of SO3 can be increased I need the answer for my exam i would be thankful if anyone answered it THANK YOU

Chemistry 1
Which shows equilibrium between solute and solvent? I'm stumped. a. 2 M CaCl2 b. 1 g Na2CO3 & 100 mL H2O c. 2 mL methanol & 4 mL hexane d. 1 mL H2O & 3 mL ethanol

Chemistry 1
What theoretical mass of MgO is produced if 0.150 g Mg3N2 is produced by strongly heating a 2.000 g sample of Mg in air?

Chemistry
A 26.3 gram sample of solid potassium chlorate decomposed and produced 9.45 grams of oxygen gas. What is the percent yield of oxygen?

chemistry
In an adiabatic coffee cup, a 75mL of 1.0M HCl and 50mL of 1.0M HaOH were neutralize. The initial temperature is 22.1 C and the final temperature is 26.3 C. What is the enthalpy? S=4.18g/JC and the heat capacity of the adiabatic coffee

Chemistry
1.Which of the following is most soluble in water and why ? a.Ag2SO4 b.Hg2SO4 c.MnCO3 d.CaSO4 2.PH of which salt is same for 1M and 5M solution both and why? a.HCOONa b.C6H5NH3^+Cl c.NH4CN d. NaCN 3.NH4OH is highly soluble in and why ? a.CuSO4 b.AgNO3 c.NH4Cl d.Both 1&2

Chemistry
Phthalic acid, H2C8H404, is a diprotic acid used in the synthesis of phenolphthalein indicator. Ka1= 1.2x 10^-3, and Ka2 = 3.9 x 10^-6. a) Calculate the hydrongen-ion concentration of a .015 M solution. b) What is the concentration of the C8H4O4^2- ion in the solution?

Chemistry
What is the relationship between the energy of a single photon and the energy of a mole of photons? This is very confusing.

chemistry
Write a balanced equation for the reaction of liquid bromine with chlorine gas.

AP Chemistry
The rate constant for the equation, 2C2F4 → C4F8, is 0.05 M^−1· s^−1. We start with 0.111 mol C2F4 in a 3.00-liter container, with no C4F8 initially present. What will be the concentration of C2F4 after 1.00 hour? Answer in units of M.

chemistry
In an adiabatic coffee cup, a 75mL of 1.0M HCl and 50mL of 1.0M HaOH were neutralize. The initial temperature is 22.1 C and the final temperature is 26.3 C. What is the therapy? S=4.18g/JC and the heat capacity of the adiabatic coffee cup is 18.80J/C.

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