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November 28, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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Chemistry
Cambridge uses FA 1, FA 2 etc to name chemicals or solutions. What does FA stand for?
Monday, October 13, 2014 at 12:15pm

chemistry
A carbonate ion, CO32−, can participate in an acid-base reaction. How should the carbonate ion be classified?
Monday, October 13, 2014 at 12:11pm

chemistry/math
5.0 moles of solid sodium chloride (NaCl) are used to prepare a 5.0 M NaCl solution. What is the volume of the solution?
Monday, October 13, 2014 at 12:06pm

chemistry
How many moles of magnesium chloride are formed when 55 mL of 0.70 M HCl is added to 42 mL of 1.204 g Mg(OH)2? Mg(OH)2(s) + 2HCl(aq) MgCl2(aq) + 2H2O(l) A. 0.019 mol B. 0.012 mol C. 0.021 mol D. 0.039 mol
Monday, October 13, 2014 at 11:45am

Chemistry
Molecular, ionic, and net ionic equations for ammonium chloride + potassium sulfate. Also what is the observation. Is it 2NH2Cl + Na2SO4 = (NH4)2SO4 + 2NaCl???? Please help!
Monday, October 13, 2014 at 5:03am

Chemistry 101
A solution containing 83.100 g of sodium hydroxide [molar mass = 40.0 g/mol] was neutralised using phosphoric acid. Calculate the moles of sodium phosphate formed (assuming that the reaction goes to completion). Give your answer to three significant figures. I'm not sure ...
Monday, October 13, 2014 at 2:19am

chemistry
To resolve an object in an electron microscope, the wavelength of the electrons must be close to the diameter of the object. What kinetic energy must the electrons have in order to resolve a protein molecule that is 7.00 nm in diameter? Take the mass of an electron to be 9.11&...
Sunday, October 12, 2014 at 11:44pm

chemistry
A beaker contain 300.ml of a 0,20 M Pb(NO3) solution. If 200 ml of 0,20M solution og MgCl2 is added to the beaker, What will be the concentration of Pb2+ ions in the resulting solution
Sunday, October 12, 2014 at 11:22pm

chemistry
An unknown diprotic acid requires 26.66 mL of 0.117 M NaOH to completely neutralize a 0.845 g sample. what is the molar mass of the acid?
Sunday, October 12, 2014 at 10:03pm

Organic Chemistry
Aqueous sodium bicarbonate was used to wash the crude t-pently chloride. What was the purpose of the wash? give equations.
Sunday, October 12, 2014 at 8:12pm

chemistry
A student weighs out 0.568 g of KHP (molar mass = 204 g/mol) and titrates to the equivalence point with 36.78 mL of a stock NaOH solution. What is the concentration of the stock NaOH solution? KHP is an acid with one acidic proton. a. 3.15 M b. 0.0757 M c. 0.943 M d. 0.100 M ...
Sunday, October 12, 2014 at 7:10pm

chemistry
5.00g aluminum sulfide and 10.0g water react according to the reaction: Al2S3 + 6 H2O -> 2 Al(OH)3 + 3 H2S What is maximum mass of H2S that can be formed? What mass of excess reactant remains when the reaction is complete?
Sunday, October 12, 2014 at 5:31pm

chemistry
What weight of lead nitrate in grams would need to be dissolved in 400 mL of water to prepare a 270 ppm solution of Pb2+?
Sunday, October 12, 2014 at 5:24pm

Chemistry
It is easy but I cannot solve or do buffer questions/slns.. Please help. Describe the preparation of 500 ml of 1 M phosphate buffer at pH 7.2.
Sunday, October 12, 2014 at 3:59pm

Chemistry
Orbital Hybridization of CH2Cl2?
Sunday, October 12, 2014 at 3:39pm

CHEMISTRY
If precipitation of BaSO4 is incomplete due to inadequate heating or insufficient time what will happen to the sulfate percent error determination? And why?
Sunday, October 12, 2014 at 3:31pm

Chemistry
If the density of ocean water at depth of 10,000m is 1.071g/ml and if 25.0g of water at that depth contains 190mg of KCl what is the molarity of KCL?
Sunday, October 12, 2014 at 3:01pm

chemistry
An analytical procedure requires a solution of chloride ions ,How many grams of CaCl2 must be disolved to make2.15L of 0.0520 M C
Sunday, October 12, 2014 at 3:00pm

Chemistry
If you wanted to make a barometer that had a column of liquid about 6ft tall what would the density of the liquid have to be? 1meter=3.28ft 1in=2.54cm Density Hg=13.6g/ml 1atm=760torr
Sunday, October 12, 2014 at 2:42pm

chemistry
An experiment to determine compound partition among air, water, and soil phases was conducted by adding 1 gram of the compound to a reactor that had 1 m3 of air, 0,001 m3 of water0 and 100 g of solid. The reactor was at atmodpheric pressure and at aconstant tepmrature 20 C The...
Sunday, October 12, 2014 at 2:12pm

chemistry
You mix 50.0 ml of 2.0 M HCl and 50.0 ml of 2.0M NaOH. The temperature of the resulting solution increases from 22.5 degrees celcius to 32.3 degrees celcius. What is the q of the calorimeter
Sunday, October 12, 2014 at 2:02pm

chemistry
a saturated solution of potassium chloride prepared at 60degree celsius is allowed to cool at room remperature
Sunday, October 12, 2014 at 11:43am

Chemistry
How many grams of C are there in a sample of C that contains the same number of moles as a 25.4 gram sample of Ca?
Sunday, October 12, 2014 at 10:14am

Chemistry
The mass of an electron is 9.11× 10–31 kg. What is the uncertainty in the position of an electron moving at 5.00 × 106 m/s with an uncertainty of Δv = 0.01 × 106 m/s?
Sunday, October 12, 2014 at 9:23am

CHEMISTRY
how to calculate the weight of solute req'd to prepare 1 liter of 1 normal of: a.) LiOH b.) phosphoric acid my work: formula= gew/L or w/ewxL i get their mw then divide it to their H/OH so i can get EW then multiply it to 1. a.) 24 g/mol/1 b.) 98g/mol/3 i dont know what&#...
Sunday, October 12, 2014 at 5:55am

CHEMISTRY
How many mL of pure isopropyl alcohol is needed to prepare 250 mL of 70% isopropyl alcohol (C3H7OH). I'm thinking if i should use vol of solute/vol of sol'n but it doesn't fit the formula and im confuse it. please help me
Sunday, October 12, 2014 at 5:49am

CHEMISTRY HELP
Calculate boiling point and freezing point of this solution which contains 5.85g of C6H12O6 in 255g H2O. pleasee
Sunday, October 12, 2014 at 5:06am

Chemistry
A precipitate forms when solutions of sodium carbonate and calcium nitrate are combined. Write the net ionic equation for this reaction. Please help
Sunday, October 12, 2014 at 4:18am

chemistry
If you wanted to make a barometer that had a column of liquid about 6 feet tall, what would the density of the liquid have to be? 1 meter = 3.28 ft 1 inch = 2.54 cm Density Hg = 13.6 g/mL 1atm = 760 torr
Sunday, October 12, 2014 at 3:40am

CHEMISTRY
Calculate boiling point and freezing point of this solution which contains 5.85g of C6H12O6 in 255g H2O. pleasee
Sunday, October 12, 2014 at 3:03am

chemistry
0.6905kg zinc reacts with hydrochloric acid.how many balloons can be filled with the hydrogen gas where the pressure inside the balloon is 790metrehg and temperature is 27 degree centigrade .
Sunday, October 12, 2014 at 2:32am

chemistry
Calculate the concentration of iron(III) in 2.0 M of 9 ml HCL and 0.00050 M of 1 ml FeCl3? Please help me :(
Sunday, October 12, 2014 at 1:50am

Chemistry
What is the mechanism of an aldehyde reacting with fehlings solution and tollens reagent? I know it is oxidised to a carboxylic acid, but i want to know the mechanism. Thank you.
Sunday, October 12, 2014 at 1:17am

chemistry
A 300mL solution was made by dissolving 5.0g of MgCl2 in water. What is its molarity?
Saturday, October 11, 2014 at 11:50pm

CHEMISTRY
how many grams of glucose, C6H12O6 and water are in 600g of 5.5% by mass glucose solution? please indicate the general formula to use to solve this problem.
Saturday, October 11, 2014 at 11:47pm

Chemistry
My lab had done protein crystallography with lysozyme. Two solutions were used to prepare the crystallization: lysosome solution and the precipitate solution. 1) There was a distinct amount of starting material in a well. what would that do to the size of the crystals if the ...
Saturday, October 11, 2014 at 11:18pm

CHemistry
write the balanced net ionic equation that shows the formation of Fe(OH)3 in the reaction of iron (III) nitrate with sodium hydroxide. Please help
Saturday, October 11, 2014 at 10:04pm

Chemistry
Calculate the fourth ionization energy of beryllium in J atom^-1 & kJ mol^-1 units
Saturday, October 11, 2014 at 10:04pm

Chemistry
a 175.0 ml solution is made up of 20.0g of titanium(iii) chloride and H2O. What is it's molarity? I am just trying to check my work. M= 0.1296/0.175 =0.740
Saturday, October 11, 2014 at 9:41pm

Chemistry
Assume that you start with 2 mole(s) of magnesium metal, determine: The number of grams of MgO(s) that would be produced in the following reaction (enter your answer with 4 significant figures): Mg(s) + 1/2O2(g) → MgO(s)
Saturday, October 11, 2014 at 9:34pm

Chemistry
Write the balanced molecular equation for the reaction between lithium phosphate and calcium nitrate.
Saturday, October 11, 2014 at 9:26pm

chemistry
An alternative approach to bomb calorimetry is toestablish the heat capacity of the calorimeter, exclusive of the water it contains. The heat absorbed by the water and by the rest of the calorimeter must be calculated separately and then added together. A 1.148g sample of ...
Saturday, October 11, 2014 at 7:04pm

Chemistry
How much heat would you need to melt 20.0 L of ice that had frozen on a fruit tree.
Saturday, October 11, 2014 at 4:03pm

AP Chemistry
1. If alum is heated at first too strongly causing it to splatter out of the crucible what effect will this have on the determination of the water hydration? 2. If alum is heated insufficiently what effect will this have on the determination of the water hydration? 3. If not ...
Saturday, October 11, 2014 at 3:33pm

CHEMISTRY
Write a balanced chemical equation for the reaction of solid vanadium(V)({\rm V}) oxide with hydrogen gas to form solid vanadium(III)({\rm III}) oxide and liquid water.
Saturday, October 11, 2014 at 2:48pm

CHemistry
Assuming the final concentration of chloride anion after the addition of HCl (precipitation step) was 0.1M, what is the remaining concentration of Ag+ in the solution? (pKsp for AgCl = 9.74)
Saturday, October 11, 2014 at 2:20pm

chemistry
you have not added enough sodium hydroxide to precipitate all the copper as copper hydroxide. How could you tell that not all the copper had precipitated?
Saturday, October 11, 2014 at 2:04pm

chemistry
When a metal was exposed to light at a frequency of 3.86× 1015 s–1, electrons were emitted with a kinetic energy of 3.60× 10–19 J. What is the maximum number of electrons that could be ejected from this metal by a burst of light (at some other frequency) ...
Saturday, October 11, 2014 at 12:32pm

chemistry
how to do a research paper
Saturday, October 11, 2014 at 11:51am

chemistry
What is the percentage yield of the reaction of 4.9 g isoamyl alcohol with 4.9 g of acetic acid if 3.5 g of isoamyl acetate product is obtained after distillation? Enter your answer, without a % symbol, to 2 sig. figs.
Saturday, October 11, 2014 at 3:56am

Chemistry URGENT!!
Which anions have the largest and smallest radii? Thank you!!
Friday, October 10, 2014 at 10:07pm

Chemistry
Which positive ion (cation) has the smallest radius? Please help! Thanks!
Friday, October 10, 2014 at 9:25pm

Chemistry
If 43.2 mL of 2.46 M HClO4 solution completely reacts with a 75.0 mL sample of a sodium hydroxide solution, what is the molarity of the sodium hydroxide solution? (hint: write the complete balanced rxn)
Friday, October 10, 2014 at 9:17pm

chemistry
a solution is made by mixing 38.0 ml of ethanol C2H6O, 62.0mL of water. assuming ideal behavior, what is the vapor pressure of the solution at 20 C
Friday, October 10, 2014 at 9:08pm

Chemistry
Imagine that you have a 7.00L gas tank and a 4.00L gas tank. You need to fill one tank with oxygen and the other with acetylene to use in conjunction with your welding torch. If you fill the larger tank with oxygen to a pressure of 145atm , to what pressure should you fill the...
Friday, October 10, 2014 at 7:29pm

College chemistry
What is the volume in milliliters of 0.1069 M Cr2O72- required to react with 252.4 mL of 0.08013 M Cl- according to the reaction below? 6 Cl-(aq) + Cr2O72-(aq) + 14 H+(aq) ® 3 Cl2(g) + 2 Cr3+(aq) + 7 H2O(l)
Friday, October 10, 2014 at 4:59pm

Chemistry
Many portable gas heaters and grills use propane, C3H8(g). Using enthalpies of formation, calculate the quantity of heat produced when 19.0g of propane is completely combusted in air under standard conditions. Assume that liquid water is forming.
Friday, October 10, 2014 at 4:49pm

Chemistry
Please Help!! I dont know how to balance this redox equation! I've been trying to solve this for hours and I'm getting nowhere Fe(s) + HClO4 (aq) --> H (g) + FeClO4 I tried balancing and I got these Fe(s) + HClO4 (aq) --> H2 (g) + Fe(ClO4)3 and 2Fe(s) + 6HClO4 (...
Friday, October 10, 2014 at 2:05pm

chemistry
Suppose you add a small ice cube to room temperature water in a coffee cup calorimeter. What is the final temperature when all the ice is melted? Assume that you have 200.0 mL of water at 25.0 degrees Celsius and the ice cube weighs 15.0 g and is at 0.0 degrees Celsius before ...
Friday, October 10, 2014 at 1:34pm

Chemistry
If the minimum (threshold) energy for the emission of an electron from the surface of a particular metal is 3.90 X 10-19 J, what is the kinetic energy of an electron emitted from the surface of the metal when it is irradiated by electromagnetic radiation of wavelength 213 ...
Friday, October 10, 2014 at 10:28am

chemistry
100 mL of a 0.1 mM buffer solution made from acetic acid and sodium acetate with pH 5.0 is diluted to 1 L. What is the pH of the diluted solution?
Friday, October 10, 2014 at 7:12am

Chemistry
What is the wavelength of a photon having a frequency of 71.6 THz? So I know 1 THz = 10 to the power of 15 Hz And c= 3 x 10 to the 8th and h= 6.63 x 10 to the -34th
Friday, October 10, 2014 at 2:51am

Chemistry
I have the question find the balanced equation when Fe(s) is placed in HClO4 (aq). How do I balance this redox reaction? I'm not entirely sure its right but the unbalanced equation I have so far is Fe (s) + HClO4 (aq) -->Fe(ClO4)3 + H2 I'm not sure what to do after ...
Friday, October 10, 2014 at 1:19am

chemistry
How many moles of aluminum are presented in a 0.856g sample of aluminum can? Assume that the can is pure aluminum.
Friday, October 10, 2014 at 12:21am

Chemistry
What are the parts of a calorimeter used in chemistry?
Thursday, October 9, 2014 at 9:55pm

chemistry
In the laboratory a student combines 25.9 mL of a 0.223 M magnesium bromide solution with 23.3 mL of a 0.615 M magnesium acetate solution. What is the final concentration of magnesium cation ? ..... M
Thursday, October 9, 2014 at 6:55pm

chemistry
Can you make a 2 carbon molecule of Ketone?
Thursday, October 9, 2014 at 5:31pm

Chemistry
If 14.23 mL of 0.203 M NaOH is required to neutralize .269 g of a monoprotic unknown acid, what is the molecular weight of the unknown acid?
Thursday, October 9, 2014 at 1:07pm

chemistry
How many hydrogen atoms are in 0.0542 mol of H2SO4? Answer in units of atoms H
Thursday, October 9, 2014 at 12:25pm

chemistry
Calculate (a) the moles and (b) the mass of magnesium carbonate at the start if 0.2 moles of sulfuric acid is added to the magnesium carbonate and the excess sulfuric acid made up to a 250 cm3 solution. 25 cm3 of this solution required 0.03 moles of sodium hydroxide for ...
Thursday, October 9, 2014 at 12:22pm

Chemistry
What is the pH of a solution containing both 0.954 M formic acid (HCO2H, Ka = 1.8x10-4) and 1.260 M phenol (HC6H5O, Ka = 1.6x10-10)?
Thursday, October 9, 2014 at 12:12pm

chemistry
A solution is prepared by mixing 4.62 grams of potassium hydroxide in 1.00 L of water. After that, 250.0 mL of a 0.100 M solution of HCl is added to the solution. What is the resulting pH of the final mixture?
Thursday, October 9, 2014 at 12:03pm

chemistry
An aqueous solution of nitric acid is standardized by titration with a 0.121 M solution of calcium hydroxide. If 24.5 mL of base are required to neutralize 15.4 mL of the acid, what is the molarity of the nitric acid solution?
Thursday, October 9, 2014 at 9:21am

Chemistry
How many liters of liquid nitrogen are produced when 360.0 L of nitrogen gas is liquified at 77.36 kl
Thursday, October 9, 2014 at 1:50am

Chemistry
Calculate amount of 1 M acetic acid and 1M sodium acetate necessary to prepare 50 ml of a 0.15 M buffer at ph 4.80. (pka acetic acid =4.74)
Wednesday, October 8, 2014 at 11:29pm

Organic Chemistry
If your carboxylic acid is benzoic acid, how many moles of benzoic acid are present in your sample (0.30g, and it is a mixture of three components of equal mass)?
Wednesday, October 8, 2014 at 11:07pm

chemistry
Experimental Molar Ratio of Copper in CuxOy
Wednesday, October 8, 2014 at 9:58pm

Chemistry
Moles of Copper in the original .825g of Copper Oxide
Wednesday, October 8, 2014 at 9:38pm

chemistry
How many oxygen atoms are in 0.07 mol of dinitrogen pentoxide (N2O5)? Answer in units of atoms
Wednesday, October 8, 2014 at 9:10pm

Chemistry
if all the macro-molecules are made mainly of the elements CHO, how are they different?
Wednesday, October 8, 2014 at 7:07pm

chemistry
20.0 mL of a 2.2 M lead (II) nitrate solution is mixed with 100.0 mL of a 0.75 M magnesium sulfate solution. What is the concentration of nitrate ions in the resulting solution?
Wednesday, October 8, 2014 at 6:41pm

Chemistry
If one assumes the volumes are additive, what is the concentration, in mol/L, of NO3− in a solution obtained by mixing 263 mL of 0.167 M KNO3, 311 mL of 0.404 M Mg(NO3)2, and 713 mL of H2O?
Wednesday, October 8, 2014 at 5:46pm

Chemistry
What volume of 5.0 M H2SO4 should be diluted to 100mL to prepare a 0.25 M H2SO4 M solution? I know the molar mass of H2SO4 is 98g but I'm not sure where exactly that fits in and how I'm supposed to get it to be diluted. Thank you!
Wednesday, October 8, 2014 at 4:33pm

chemistry
A solution of silver perchlorate (AgClO4) is made by dissolving 40.4 g of pure silver perchlorate and diluting it to exactly 140 ml. What is the solutions molarity? Can you just go through the steps of what I need to do? I'm so confused. Thanks
Wednesday, October 8, 2014 at 4:25pm

Chemistry
Calculate how many grams of O2(g) can be produced from heating 37.0 grams of KClO3(s). Formula: 2KClO3 = 2KCl + 3O2
Wednesday, October 8, 2014 at 4:24pm

chemistry
Calculate how much K3Fe(CN)6 [MW: 329.24] you would need to weigh out to make a 1x10-3 M solution dissolved in 0.2 M NaNO3 in a 100 ml volumetric so far i have worked out that 0.329 g will give me the 1x10-3 M, but im confused when it is dissolved into the NaNO3.
Wednesday, October 8, 2014 at 2:31pm

Chemistry
Assign the two absorptions found above 3000 cm-1 in acetamide. Why are these absorptions missing in n,n-dimethylacetamide
Wednesday, October 8, 2014 at 2:28pm

Chemistry
A gas mixture composed of helium and argon has a density of 0.846g/L at a 734mmHg and 298 K. What is the composition of the mixture by volume?
Wednesday, October 8, 2014 at 1:36pm

Chemistry
A 0.700 g sample containing Ag2O and inert material is heated, causing the silver oxide to decompose according to the following equation: 2 Ag2O(s) → 4 Ag(s) + O2(g) If 13.8 mL of gas are collected over water at 27°C and 1.00 atm external pressure, what is the ...
Wednesday, October 8, 2014 at 1:31pm

Chemistry
Give a acid-base pairs which produce Na2CO3 as a salt
Wednesday, October 8, 2014 at 1:22am

Chemistry
A solution of ammonia and water contains 1.60×1025 water molecules and 8.50×1024 ammonia molecules. How many total hydrogen atoms are in this solution?
Wednesday, October 8, 2014 at 1:11am

chemistry
what could cause the difference in the actual number of mole and the expected number of mole in copper oxide?
Tuesday, October 7, 2014 at 11:13pm

chemistry
what is the molar ratio of 0.114 copper to 0.116 oxygen? Then how do you make an empirical formula from this information?
Tuesday, October 7, 2014 at 11:05pm

chemistry
in a empirical formula lab how do you calculate the number of moles of Cu in 0.0114 moles of CuSo4*H2O? Thanks
Tuesday, October 7, 2014 at 10:38pm

Chemistry
---This was the previous one--- Substances A, B, and C can all act as oxidizing agents. In solution, A is green, B is yellow, and C is red. In the reactions in which they participate, they are reduced to A-, B-, and C- ions, all of which are colorless. When a solution of C is ...
Tuesday, October 7, 2014 at 10:36pm

chemistry
A metal rod has a mass of 17.62 g. A graduated cylinder contains 29.9 mL of water. The metal rod is added to the cylinder. The final water level in the cylinder is 36.1 mL. What is the density of the metal rod?
Tuesday, October 7, 2014 at 10:35pm

chemistry 112
A volume of 60.0mL of aqueous potassium hydroxide (KOH) was titrated against a standard solution of sulfuric acid (H2SO4). What was the molarity of the KOH solution if 19.2mL of 1.50 M H2SO4 was needed? The equation is 2KOH(aq)+H2SO4(aq)→K2SO4(aq)+2H2O(​l) Express ...
Tuesday, October 7, 2014 at 10:34pm

Chemistry
Earlier I asked /display.cgi?id=1412727782 (tyvm btw) Say you have these A, B, and C solutions. Now you have an unknown colorless solution that contains either NaA, NaB, or NaC. In solution, each salt dissociates completely into the Na+ ion and the anion A-,B-, or C- (which ...
Tuesday, October 7, 2014 at 10:15pm

Chemistry
A reaction uses 4.5 grams of oxygen and an excess of nitrogen. How many grams of dinitrogen pentoxide are produced?
Tuesday, October 7, 2014 at 10:13pm

chemistry
How many grams are in 2.5 moles of magnesium hydroxide
Tuesday, October 7, 2014 at 9:36pm

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