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July 27, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
how can we produce ethane from methane?
Wednesday, April 6, 2016 by tasnuba

Chemistry
Oxalic acid & phosphoric acid are polyprotic acid. For both acids, provide the equilibrium reactions showing all of the dissociation steps and the expressions for each acid dissociation constans.
Wednesday, April 6, 2016 by Ziera

college chemistry
calculate the equilibrium constant for the following reaction at 298k given that DeltaGrxn=2.8kj/mol N2O4-2NO2 I thought to get K you use the expression K=e^(-deltaG/(RT)) but I cant get the same answer my professor put down which is 3.1
Wednesday, April 6, 2016 by Jeremy

chemistry
If 5.40 kcal of heat is added to 1.00 kg of water at 100⁰C, how much steam at 100⁰C is produced? Show all calculations leading to an answer. Please help?
Wednesday, April 6, 2016 by emily

chemistry
You have two sealed jars of water at the same temperature. In the first jar there is a large amount of water. In the second jar there is a small amount of water. Using 3 -4 sentences explain how the vapor pressure of water in the first jar compares with the vapor pressure of ...
Wednesday, April 6, 2016 by emily

chemistry
What volume of a oxygen at STP was collected? oxygen gas is collected over water at a temperaturee of 10 degrees C and a pressure 1.2 atm. The volume of gas plus water vapor collected is 293ml.
Wednesday, April 6, 2016 by dee

chemistry
Why is it important to use the same pipet through out the experiment?
Wednesday, April 6, 2016 by Jimmy

science:chemistry
magnesium trioxocarbonate (IV) decomposed according to the equation MgCO3(s) -MgO2(s) + CO2(g).if 6.0g of magnesium trioxocarbonate (IV) is completely decomposed ,calculate :i. the mass of carbon (IV) oxide produced
Wednesday, April 6, 2016 by michael

Chemistry
Potassium oxide reacts with water to produce of potassium hydroxide. Please provide a balanced equation, and determine how much potassium oxide is needed to produce 80.5g of potassium hydroxide?
Tuesday, April 5, 2016 by Nicole

high school chemistry
You are going to titrate 20 mL of .10M HCL with 0.10M NaOH. What is the pH at the equivalence point. How do I figure out the equivalence point when I have already figured out that the initial pH of the HCL and NaOH are both 1?
Tuesday, April 5, 2016 by Jerome

Chemistry
How many mole of fe2o3 will be formed?
Tuesday, April 5, 2016 by Daniel Miller

Chemistry
How many kilojoules are absorbed when 266 g of PCl5 reacts? PCl5(g)→PCl3(g)+Cl2(g)ΔH=+67k​J
Tuesday, April 5, 2016 by Cara

Chemistry
How many kilojoules are released when 130 g of Si reacts with chlorine? Si(s)+2Cl2(g)→SiCl4(g)ΔH=W​22;657kJ
Tuesday, April 5, 2016 by Cara

chemistry 107
participates that forms when aqueous barium nitrate and potassium sulphate are mixed
Tuesday, April 5, 2016 by obi mark

Chemistry
Water's unique properties allow it to- a.dissolve aqueous solutions b.dissolve ionic and nonpolar covalent molecules c.dissolve ionic and polar covalent molecules d.dissolve ionic, covalent and metallic molecules is it c, because i know water is polar?
Tuesday, April 5, 2016 by Boberto

chemistry
What characteristic of water will remain the same regardless of what may be dissolved in it? a.the ratio of hydrogen to oxygen b.the freezing temperature c.the ability to refract light d.the hydroxide ion concentration i think its a?
Tuesday, April 5, 2016 by Boberto

chemistry
Which process(es) affect the speed of dissolution? a.particle size and stirring only* b.stirring only c.particle size, temperature and stirring d.particle size only
Tuesday, April 5, 2016 by Boberto

chemistry
When water freezes and becomes solid ice, the hydrogen bonds create a crystal structure and there is fixed space between each water molecule. This causes ice to? a.become more dense than liquid water because it is a solid* b.become less dense than liquid water and therefore ...
Tuesday, April 5, 2016 by Boberto

Chemistry
The reaction through which carbon changes from graphite to diamond form is represented by the equation C(graphite) ---> C(diamond) delta H: ? Using the reactions below, determine the amount of heat absorbed in the change of one mole of graphite to one mole of diamond C(...
Tuesday, April 5, 2016 by Rose

Chemistry
1) If 0.5 moles of a mono alkanoic acid weighs 44g,determine the molecular formular. 2) molecular formular =emprical * n. 3) molecular formular = 44*0.5
Tuesday, April 5, 2016 by Miracle

Chemistry
With an equilibrium constant of k=1.3 if NaOH and MgCL2 are added in stoichiometric ratio and 1.2 mol of NaOH are present at equilibrium, how much precipitate is produced (in moles)?
Tuesday, April 5, 2016 by Bryce

Chemistry
For the H 3 CNCO molecule, (Note: The atoms are bonded in the order CNCO, with the three H atoms bonded to the first carbon atom.) answer the following questions. What is the ideal H-C-H bond angle? (0, 30, 45, 60, 90, 109, 120, 145, or 180.) What is the ideal N-C-O bond angle...
Tuesday, April 5, 2016 by Anonymous

chemistry
a 25% by mass H2SO4 solution has a density of 1.07 g/cm3 how much solution contains 13.37 g of H2SO4
Tuesday, April 5, 2016 by Annette lobos

Chemistry
Draw the most important Lewis structure for the H 3 CNCO molecule. (Note: The atoms are bonded in the order CNCO, with the three H atoms bonded to the first carbon atom.) After you have identified the most important Lewis structure, answer the following questions. What is the ...
Tuesday, April 5, 2016 by Anonymous

Chemistry
Which of the following molecules is/are bent or V-shaped? C2H2 SiF4 H2S SO2 CF4 HCN NH3 COS H2O O3 SO3 AsH3 CS2 BF3 N2O HN3 PF3
Tuesday, April 5, 2016 by Anonymous

Chemistry
Which of the following molecules is/are nonpolar? H2S O3 COS C2H2 SO2 SiF4 PF3 HCN NH3 CS2 HN3 SO3 CF4 BF3 H2O N2O AsH3
Tuesday, April 5, 2016 by Anonymous

Chemistry
If you produce 3.5 moles of H2, how many moles of aluminum did you use in the reaction?
Tuesday, April 5, 2016 by Tom

Chemistry
What volume of 1.00M ca(oh)2 is needed to neutralize 250.0mL of 0.100M HCL?
Tuesday, April 5, 2016 by Sierra

chemistry
A mixture of 0.2 moles of alcohol A and 0.5 moles of alcohol B has a total vapour pressure of 40 mmHg at 297 K. If the mixture obeys Raoult's law, find the vapour pressure of pure B at 297 K given that the pressure of a pure A is 20 mmHg at 297 K.
Tuesday, April 5, 2016 by jay

Chemistry
The formation constant* of [M(CN)4]2– is 7.70 × 1016, where M is a generic metal. A 0.150-mole quantity of M(NO3)2 is added to a liter of 0.870 M NaCN solution. What is the concentration of M2 ions at equilibrium?
Tuesday, April 5, 2016 by Meghan

Chemistry
Suppose a solution contains 0.21 M Pb2 and 0.41 M Al3 . Calculate the pH range that would allow Al(OH)3 to precipitate but not Pb(OH)2.
Tuesday, April 5, 2016 by Jackson

Chemistry
A solution contains 0.0390 M Pb2 (aq) and 0.0390 M Sr2 (aq). If we add SO42–(aq), what will be the concentration of Pb2 (aq) when SrSO4(s) begins to precipitate? I am just completely lost on this one.
Tuesday, April 5, 2016 by John

Chemistry
Explain why heat or acid causes the protein to unfold? What is happening chemically? Is this correct what I am saying? if not please help. The folding of proteins is mostly the result of intermolecular forces of attraction such as hydrogen bonding. Both hear and acid (H+) can ...
Tuesday, April 5, 2016 by Anonymous

Chemistry
Consider the following three reactions: Ca(s) + 2H2O(l) ---> Ca2+(aq) + 2OH^- (aq) + H2(g) CaO(s) + H2O(l) ---> Ca2+ (aq) + 2OH^- (aq) H2(g) + 1/2O2 (g) ----> H2O (l) Delta H = 430.75 kJ Delta H = 81.55 kJ Delta H = 285.63 kJ Determine Delta H for the overall reaction...
Tuesday, April 5, 2016 by Rose

Chemistry
2Mg +O2 > 2MgO Write experiment to prove that the product is basic oxide?
Tuesday, April 5, 2016 by Venk

Chemistry
If the hydrogen ion concentration is 5.32 x 10–9 M, find the hydroxide ion concentration.
Monday, April 4, 2016 by Damla

Chemistry
How much energy will be liberated upon the combustion of 12.5 grams of ethene? C2H4(g) + 3O2(g) ----> 2CO2(g) + 2H2O(g) Delta H = -1387.4 kj
Monday, April 4, 2016 by Rose

Chemistry
Number of Moles of AgNO3 when 0.25 grams of NaCl react with AgNO3
Monday, April 4, 2016 by melanie

Chemistry-Dr.Bob222
Determine [OH-] of a solution that is 0.135 M in CO3^2-. I got 0.00532.
Monday, April 4, 2016 by Nevaeh

Chemistry
Calculate the concentrations of Cd ⁺ ², [Cd (CN)₄-²] and CN at equilibrium when they dissolve mole of 0.42 Cd (in the ₃)²⁺ 2.50 M. Given: Kf = 7, 1 x 10 ^16
Monday, April 4, 2016 by Kelly

Chemistry
5.88 moles of nitrogen and 16.2 moles of oxygen are mixed until the equilibrium is established 11.28 moles of nitric acid are formed calculate the value of equilibrium constant
Monday, April 4, 2016 by Mohammad

organic chemistry
In an eudiometer 20cm^3 of a gaseous hydrocarbon A is mixed with 150 cm^3 of oxygen. The combustion of A is initiated by an electric spark. After cooling and condensing the vapor the volume of the gaseous mixture is 110cm^3 of which 80cm^3 causes turbidity of limewater. The ...
Monday, April 4, 2016 by angy

organic chemistry
In an eudiometer 20cm^3 of a gaseous hydrocarbon A is mixed with 150 cm^3 of oxygen. The combustion of A is initiated by an electric spark. After cooling and condensing the vapor the volume of the gaseous mixture is 110cm^3 of which 80cm^3 causes turbidity of limewater. The ...
Monday, April 4, 2016 by angy

Chemistry
Calculate the Ksp for silver sulfate if the solubility of Ag2SO4 in pure water is 4.5 g/L. Ag2SO4(s) <--> 2Ag^+(aq) + SO4^2-(aq)
Monday, April 4, 2016 by Ayaka

Chemistry- Dr.Bob222
Ammonium hydroxide is commonly advertised as an ingredient in some window cleaners. Rank the following in order of decreasing concentrations in these solutions: NH4OH, NH4+, OH-, NH3. Explain your reasoning. (Note that kb for ammonia = 1.8 x 10^-5. So does an unionized ion ...
Sunday, April 3, 2016 by Nevaeh

Chemistry
What is the difference between an Arrhenius acid/base, a Brønstead Lowry a/b and a Lewis a/b?
Sunday, April 3, 2016 by Nurah

Chemistry
Boron trifluoride (BF3) has properties ordinarily associated with acids. According to what acid base theory or theories is it considered an acid? Is it an Arrhenius, Brønstead, Or Lewis Definition? Or is it all? Thank you very much.
Sunday, April 3, 2016 by Nurah

Chemistry
You have 1.0 liter of .45 M HCLO (aq). At 25 degrees Celsius, Ka= 3.5x10^8 for this acid. Calculate the pH of .45 M HCLO and the concentration of CLO- at equilibrium. Thank you very much for any amount of help you are willing to give me.
Sunday, April 3, 2016 by Nurah

chemistry
to complex ( K2[Cu(C2O4)2]H2O, add 1 com of dil. H2SO4. Add KI; then add 1-2cm3 choloform and shake gently. what are the observations.
Sunday, April 3, 2016 by jamie

Chemistry - Dr.Bob 222
The pH scale ranges from 0 to 14. What is the range of the hydronium ion concentration covered by this scale?
Sunday, April 3, 2016 by Nevaeh

Chemistry
For the following chemical reaction HCN(aq)+KOH(aq)--->H2O(l)+KCN(aq) Write the net ionic equation, including the phases.
Sunday, April 3, 2016 by Ann

Chemistry
I need help with this question Which would have a higher boiling point? a.1.0 M KNO3 b.1.5 M KNO3 c.0.75M KNO3 d.2.0M KNO3
Sunday, April 3, 2016 by rebekah

Chemistry
I need help with this question. If the solubility of a gas in water is 6.0 g/L when the pressure of the gas above the water is 2.0 atm, what is the pressure of the gas above the water when the solubility of the gas is 3.0 g/L?
Sunday, April 3, 2016 by rebekah

chemistry
When 23g of C8H18 is combusted at STP, how many liters of carbon dioxide is produced?
Sunday, April 3, 2016 by Justin

Chemistry
A saturated aqueous solution of calcium hydroxide, Ca(OH)2, is approximately 0.13% calcium hydroxide, by mass, and has a density of 1.02 g/mL. What is the pH of such a solution?
Sunday, April 3, 2016 by Ayaka

Chemistry
Is the formation of C2H2 endothermic or exothermic?
Sunday, April 3, 2016 by Angie

Chemistry
I need help with this question, I don't know how to set up the formula to work it out? Calculate the dissociation constant of a weak monoprotic acid if a 0.08 M solution of this acid gives a hydrogen-ion concentration of 0.0001 M?
Sunday, April 3, 2016 by rebekah

Chemistry
You are completing tests using a weather balloon and want to check the temperature at 3000 meters into the air. You check if the balloon will not burst before it gets to that altitude. You will need to perform a few calculations. The manufacturer of the balloon guarantees it ...
Sunday, April 3, 2016 by Anonymous

Chemistry
If 210 mL of isopropyl alcohol is diluted with water to a total volume of 300 mL, what is the percent by volume of isopropyl alcohol in the solution? Would it be 70%??
Sunday, April 3, 2016 by rebekah

chemistry
How many grams of NaC2H3O2 are needed to prepare 350. mL of a 2.75 M solution? i got 79.0 ??
Sunday, April 3, 2016 by Boberto

Chemistry
Describe how you would make a 125 mL of 0.025 M solution of potassium dichromate?
Sunday, April 3, 2016 by Alicia

Chemistry
I need help with this question, I don't know how to do it. If 210 mL of isopropyl alcohol is diluted with water to a total volume of 300 mL, what is the percent by volume of isopropyl alcohol in the solution?
Sunday, April 3, 2016 by rebekah

Chemistry
calculate the amount of heat released, in joules, in converting 75.0 g of steam at 115 degrees of Celsius to steam at 110 degrees Celcius
Sunday, April 3, 2016 by Brandi

college general chemistry 2
a chemist titrates 70 ml of .7889M HClO solution with .6221M KOH. calculate pH at equivalence. pKa of HClO is 7.50 I am getting pH of 17.72 Is that right?
Sunday, April 3, 2016 by osp

Chemistry
320.0 gallons of 15 M nitric acid were added to a lake. The initial pH p the lake was 6.30 and the final pH was 4.60. What is the volume of the lake?
Sunday, April 3, 2016 by Meg

chemistry
Which one has more hydrogen bonding- ethanol or methanol
Sunday, April 3, 2016 by Anonymous

chemistry
suppose as student returned some unused lead nitrate to the container marked sodium nitrate. what could the student do to get all the lead ions out from the sodium nitrate?
Saturday, April 2, 2016 by mira

Chemistry
Water is a great solvent for ionic compounds because of its ??
Saturday, April 2, 2016 by Boberto

Chemistry
I have a gr 10 chemistry unit test coming up can someone please refresh my mind on this unit? and tell me what things i should practice for the test? Tyy
Saturday, April 2, 2016 by Science

chemistry
if I have 3 tablespoons of sugar (15 grams) and dissolve it in 1 cup (~237 mL) and take out 30 mL what is the molarity in the 30 mL?
Saturday, April 2, 2016 by Anonymous

Chemistry
2- Gases A2 and B2 react according to the equation: A2 + B2 → AxBy . If equimolar ( not necessarily stoichiometrically equivalent) quantities are placed in a reaction vessel with a massless, frictionless piston and allowed to react to completion. The density of the gas ...
Saturday, April 2, 2016 by Ian

chemistry
if I have 3 tablespoons of sugar (15 grams) and dissolve it in 1 cup (~237 mL) and take out 30 mL what is the molarity in the 30 mL?
Saturday, April 2, 2016 by Anonymous

Chemistry
A sample of 0, 3220g of an ionic compound containing bromide ions (Br-) is dissolved in water and treated with excess of AgNO3. If the mass of the precipitate of AgBr formed is 0, 6964g, answer: a) what percentage of bromine in molar mass? b) Give the mass of bromine in the ...
Saturday, April 2, 2016 by Elizabeth

chemistry stoichiometry
can someone explain the stoichiometry going on here... so the questions is: A solution containing 0.20g of calcium salt is passed thru a column containing the hydrogen form of a strong acid cation exchange resin. The resulting solution is neutralized with 35 mL of .1 M NaOH. ...
Saturday, April 2, 2016 by Anonymous

Chemistry
85.0 mL of 1.50 mol/L ammonium chloride solution is added to 250 mL of water. Calculate the molar concentration of the final solution The answer on the sheet says 0.381 mol/L but I keep getting 0.51
Saturday, April 2, 2016 by AmbiguousCase

Chemistry
1. A lab tech needs 1.00 L of 0.125 mol/L sulfuric acid solution for a quantitative analysis experiment. A commercial 5.00 mol/L sulfuric acid solution is available from a chemical supply company. Write out what steps he/she would follow to prepare the needed solution. Include...
Saturday, April 2, 2016 by AlphaPrimes

analytical chemistry
0.100 M NaOH (in the burette) is titrated with 25.0 mL 0.120 M CH3COOH (pKa = 4.75) in a conical flask. Determine the pH of the solution in the flask after 10 mL of the NaOH has been added.
Saturday, April 2, 2016 by TaeRa

Chemistry
A sample of 0, 3220g of an ionic compound containing bromide ions (Br-) is dissolved in water and treated with excess of AgNO3. If the mass of the precipitate of AgBr formed is 0, 6964g, answer: a) what percentage of bromine in molar mass? b) Give the mass of bromine in the ...
Saturday, April 2, 2016 by Elizabeth

Chemistry
How much NACl do i need to dissolve in grams to make 0.9%solution of 0.25l saline
Friday, April 1, 2016 by Kasey

chemistry
Net Ionic Reaction and molecular Equations of Ca3(PO4)2
Friday, April 1, 2016 by Anonymous

Chemistry
An impure sample of (COOH)2 · 2 H2O that has a mass of 2.9 g was dissolved in water and titrated with standard NaOH solution. The titration required 32.4 mL of 0.144 mo- lar NaOH solution. Calculate the percent (COOH)2 · 2 H2O in the sample.
Friday, April 1, 2016 by Bella

Chemistry
A 26.8 mL sample of a solution of RbOH is neutralized by 15.71 mL of a 1.918 M solution of HBr. What is the molarity of the RbOH solution?
Friday, April 1, 2016 by Sarah

chemistry
A certain elementary gas is triatomic and has vapour density 48 . The atomic mass of the gas is (a) 48 (b) 96 (c) 32 (d) 16 ..
Friday, April 1, 2016 by jay

Chemistry
10.5g of zinc trioxocarbonate(iv) were heated very stronglu to a constant mass and the residue treated with excess Hcl.calculate the mass of zinc chloride
Friday, April 1, 2016 by Peace

Chemistry
10.5g of zinc was heated to a constant mass and the residue treated with excess Hcl: ZnCo3+Hcl-----ZnCl2+Co2+H2O. Calculate the mass of zinc chloride that would be obtained
Friday, April 1, 2016 by Peace

chemistry
What is the oxidation number of chlorine in Al(ClO4)3? I don't understand this question, can someone help? Thank you!
Friday, April 1, 2016 by louren

Chemistry
Why is methyl orange not suitable indicator for h2c2o4 and naoh
Friday, April 1, 2016 by Ifunanya

Chemistry
The rock in a particular iron ore deposit contains 84 % Fe2O3 by mass. How many kilograms of the rock must be processed to obtain 1100 kg of iron?
Thursday, March 31, 2016 by Aria

Chemistry
What is the pH of a solution made by mixing 1.40 mL of 0.0043 molar Sr(OH)2 with 8.90 mL of 0.0029 molar Sr(OH)2 solution?
Thursday, March 31, 2016 by Kelly

Chemistry
Suppose a saturated solution of barium fluoride contains 1.5 x 10 ^ -2 M of F-. What is the Ksp of BaF2. I know that the balanced equation of this reaction is: BaF2 (s) --> Ba2+ (aq) + 2F- (aq) There is a 1:1 ratio between BaF2 and Ba2+ and there is a 1:2 ration between ...
Thursday, March 31, 2016 by Grace

chemistry
Given the balanced equation: 2 Al + Fe2O3 → Al2O3 + 2 Fe how many grams of Al2O3 will be produced if 68.1 g Al reacts with 112 g Fe2O3?
Thursday, March 31, 2016 by Winter

chemistry
Given overall reaction: P4 + 10Cl2 ---> 4PCl5 Delta H for the reaction = ? PCl5 -----> PCl3 + Cl2 Delta H = +157 kJ P4 + 6Cl2 ----> 4PCl3 Delta H = -1207 kJ Calculate the Delta H for the overall reaction.
Thursday, March 31, 2016 by John

Chemistry
. Okay 2HgO turns into 2hg + O2. What mass of Co2 can be produced from 25.0g of Fe3O4 ?
Thursday, March 31, 2016 by Maxwell

Chemistry
How do I make 500ml of a 0.3% chlorine dioxide solution from 6.4% tablets?
Thursday, March 31, 2016 by Pam

CHEMISTRY
How would you prepare 750 ml of a 10 fold dilution of a 17 M solution of acetic acid? How would you prepare 200 ml of a 20 fold dilution of a 17 M solution of acetic acid? please explain and show me the calculations.
Thursday, March 31, 2016 by rockey

Chemistry
How do I make a 500ml amount of a 0.3% aqueous solution of chlorine dioxide
Thursday, March 31, 2016 by Pam

Chemistry
What mass of copper(ii) sulphate(GFM=159.5) is required to make 400cm3 of 0.5mol/l solution
Thursday, March 31, 2016 by Callum

chemistry
If 5.40 kcal of heat is added to 1.00 kg of water at 100⁰C, how much steam at 100⁰C is produced? Show all calculations leading to an answer. I can't figure this one out, can someone help me? Thank you!
Thursday, March 31, 2016 by louren

chemistry
You have two sealed jars of water at the same temperature. In the first jar there is a large amount of water. In the second jar there is a small amount of water. Using 3 -4 sentences explain how the vapor pressure of water in the first jar compares with the vapor pressure of ...
Thursday, March 31, 2016 by louren

chemistry
I don't understand the difference between endothermic and exothermic?
Thursday, March 31, 2016 by Carly

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Homework Help: Science