Monday
December 22, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
40 ml of carbon dioxide was collected and is at 10 degree celsius and at 740 mm pressure.Calculate its volume at STP.
Monday, December 22, 2014 at 9:18am

chemistry
how many moles of cao are needed to react with excess water to produce 370 grams of calcium hydroxide
Monday, December 22, 2014 at 4:19am

Chemistry!
Liquid A has vapor pressure X, and liquid B has vapor pressure Y. What is the mole fraction of the liquid mixture if the vapor above the solution is 30% A by moles? 50% A? 80% A? (calculate in terms of x and y) I'm a little bit confused because I thought the mole fraction ...
Sunday, December 21, 2014 at 11:39pm

Chemistry
what are the intermolecular forces present in: 1. n-propyl alcohol 2. n-butanol 3. 2-butanol 4. tert-butanol alcohol 5. pentane 6. hexanes I know that the forces include- dipole-dipole, ion-dipole, dispersion, and hydrogen bonding...but I don't know how to pick which one ...
Sunday, December 21, 2014 at 6:07pm

chemistry
what volume of hydrogen will be produced if 100cm3 of ammonia is completely decomposed at constant temperature and pressure.
Sunday, December 21, 2014 at 12:58pm

chemistry
In the determination of the molar mass of a volatile liguid a 250ml flask was found to contain 0.250g of the vapor measured at 273c and 760 mmhg pressure. The molar mass is nearest the value
Sunday, December 21, 2014 at 11:01am

chemistry
A sample of co2 occupies 6.00l at 25c and 700. MmHg. What is the volume of the gas at stp
Sunday, December 21, 2014 at 10:55am

chemistry
When 40.2g of kc103 is heated what quantity of kc1 is produced
Sunday, December 21, 2014 at 10:51am

Chemistry
the molar mass of triolein is 885 g/mol, how may moles of CO2 molecules do i have
Sunday, December 21, 2014 at 12:58am

chemistry
How do I make a Smoke Bomb
Friday, December 19, 2014 at 9:34am

Chemistry
How can i explain hw i can prepare a 250ml of2.5M of HCl acid from;molecular weight of acid 36.5g\mole;density of acid 1.19g\ml and degree of purity of acid 37%
Friday, December 19, 2014 at 12:19am

Chemistry
What is the HCl concentration if 65.8mL of 0.300M NaOH is required to titrate a 15.0mL sample of the acid?
Thursday, December 18, 2014 at 4:07pm

chemistry
If we have : H2(g) + 1/2 O2(g) -> H2O(l) dHf= -285.5 Kj N2O5(g) + H2O(l) -> 2HNO3 dHf = -76.6 Kj 1/2 N2 + 3/2 O2 + 1/2 H2 -> HNO3 dHf = - 174.1 Kj then , what is the dHf of 2N2 + 5O2 -> 2N2O5
Thursday, December 18, 2014 at 2:28pm

Chemistry
I need help with this question. 1. You have a tank of helium with a volume of 10 liters that is currently under 40 atm of pressure. If you open the valve on the tank and release the helium into a room with a volume of 10,000 liters, how many atmospheres of pressure will the ...
Thursday, December 18, 2014 at 2:12pm

Chemistry
You have a tank of helium with a volume of 10 liters that is currently under 40 atm of pressure. If you open the valve on the tank and release the helium into a room with a volume of 10,000 liters, how many atmospheres of pressure will the helium now be under? Second, what ...
Thursday, December 18, 2014 at 2:07pm

chemistry
The reaction for the complete combustion of acetylene is shown below. C2H2(g) + 5/2 O2(g) -----------> 2 CO2(g) + H2O(l) ΔH = -1299 kJ Use this reaction and the data below to calculate the heat of formation for acetylene. ΔHf[H2O(l)] = -285.8 kJ/mol &#...
Thursday, December 18, 2014 at 9:01am

biology,chemistry,physics
the contact process prepares purest form of sulphuric acid 2so2+o2=2so3 calculate its kp if following concentrations are found at equilibrium so2=0.59,o2=0.05 and so3=0.259
Thursday, December 18, 2014 at 6:28am

CHEMISTRY
What is the effect of plus two degree celcius miscalibrated themometer on the enthalpy of neutralization?
Thursday, December 18, 2014 at 2:40am

chemistry
What mass of AgCl will be obtained by adding an excess of HCl to a solution of 0.34 g of AgNO3 ?
Thursday, December 18, 2014 at 1:49am

Chemistry
Carbon monoxide and molecular oxygen react to form carbon dioxide. A 49.0 L reactor at 200°C is charged with 1.14 atm of CO. The gas is then pressurized with O2 to give a total pressure of 3.54 atm. The reactor is sealed, heated to 350°C to drive the reaction to ...
Thursday, December 18, 2014 at 12:42am

Chemistry
Oxygen gas can be generated by heating KClO3 in the presence of a catalyst. KClO3 KCl + O2 (unbalanced) What volume of O2 gas will be generated at T = 35°C and P = 764.0 torr from 1.51 g of KClO3? I got .414 L and used 22.4 L for moles of O2 What's going on??
Wednesday, December 17, 2014 at 11:51pm

Chemistry
The density of 18% HCl is 1.09g/ml. Calculate its molarity (M).
Wednesday, December 17, 2014 at 10:22pm

chemistry
Household bleach is 5.25% NaOCl. What mass of NaOCl would be found in a .5 kg sample of bleach?
Wednesday, December 17, 2014 at 10:21pm

chemistry 11
Food manufacturers sometimes add calcium acetate to puddings and sweet sauces as a thickening agent. What volume of 0.500 mol/L calcium acetate, Ca(CH3COO)2 (aq), contains 0.300 mol of acetate ions? So I've been over this a hundred times and I still can't get past the ...
Wednesday, December 17, 2014 at 9:06pm

Chemistry
Calculate the %(m/m) concentration of 6.00 M H2SO4. The density of the 6.00 M H2SO4 solution is 1.34g/ml.
Wednesday, December 17, 2014 at 6:29pm

chemistry
Can someone show me how to make a smoke bomb?
Wednesday, December 17, 2014 at 6:01pm

chemistry
An equilibrium is dynamic. true or false
Wednesday, December 17, 2014 at 1:31pm

chemistry
2 mole of helium is mixed with 2 gram of hydrogen.find the molar heat capacity of the mixture at contant pressure.
Wednesday, December 17, 2014 at 3:56am

Chemistry
100 cm3 of alkane X with the general formula CxHy requires 650 cm3 of oxygen for complete combustion. Deduce the structural formulae for the isomers of X.
Wednesday, December 17, 2014 at 1:11am

chemistry
Which of the following elements can be detected by XPS? A. Hydrogen and lithium B. Boron and helium C. Lithium and boron
Wednesday, December 17, 2014 at 12:41am

Chemistry
Nuclear magnetic resonance spectroscopy can be used to study which type of atoms? A. 16O B. 1H C. 2He
Wednesday, December 17, 2014 at 12:40am

chemistry
Which of the following are excited in ultraviolet photoelectron spectroscopy? A. Valence electrons B. Core electrons C. X-rays
Wednesday, December 17, 2014 at 12:38am

Chemistry
Brass is commonly used to make musical instruments because it is easily malleable and has excellent acoustic properties. It consists of many copper atoms, with some replaced with zinc. What type of alloy is this? A. Brazing B. Substitutional C. Interstitial D. Iron
Tuesday, December 16, 2014 at 11:18pm

Chemistry
A. Ionic solid B. Molecular solid C. Covalent solid D. Graphic solid Which of this solids is soluble in water, conductive in solution, brittle and could have a melting point of 2800 C. I think the answer is A.
Tuesday, December 16, 2014 at 10:49pm

Chemistry
Which of the following affects how strongly anions and cations are attracted to each other in a solid? A. The nucleus B. Empty valence orbitals C. Distance between anions and cations D. Neutrons I the answer b.
Tuesday, December 16, 2014 at 9:42pm

chemistry
The oscillation of electrons in an antenna is an example of which type of radiation/waves/rays? A. Radio waves B. Infrared rays C. Microwaves D. VLF radiation I don't understand what is being asked so I don't have a clue on the answer.
Tuesday, December 16, 2014 at 8:56pm

Chemistry
Why are metals malleable? A. Because they reflect incoming photons B. Because they are made of atoms that have tightly held electrons C. Because of their structure and uniform bonding in all directions D. Because their lattice energy is very high I think the answer is c but I ...
Tuesday, December 16, 2014 at 8:53pm

chemistry please help drbob222
How much water is needed to dilute 25.0 ml of 0.357 mol/L hydrochloric acid to 0.246 mol/L I got 17.2 is that correct
Tuesday, December 16, 2014 at 7:57pm

chemistry
matts moped holds 1.9 gal of gas how many milliliters is that show work
Tuesday, December 16, 2014 at 7:44pm

chemistry. please help drboz222
Calculate the oxygen ppm concentration of a 3.50 kg sample of lake water that comtains 2.34 mg of dissolved oxygen
Tuesday, December 16, 2014 at 6:54pm

Chemistry
Which of the following is not true about molecular orbital theory? A. The bonding molecular orbital is filled before the antibonding orbital. B. Each molecular orbital can accommodate only one electron. C. The number of molecular orbitals formed is often equal to the number of...
Tuesday, December 16, 2014 at 6:15pm

chemistry
What is the final concentration of 35.7mL of 52.0% m/m solution that is diluted to 65.9ml? i am not sure how to caluclate this... but i know the formula is C1V1=C2V2
Tuesday, December 16, 2014 at 6:04pm

chemistry
write the mass number, atomic number,number of protons, neutrons,and electrons for He, Si, K+, N3-
Tuesday, December 16, 2014 at 6:00pm

chemistry
Using the balanced equation, 2 C2H2(g)+5 O2(g) yields 4 CO2(g)+2 H2O(g), at STP if 1mol of C2H2 burned in unlimited oxygen and the theoretical yield of carbon dioxide in liters at STP is 44.8 liters of carbon dioxide, and if 28.5 liters of carbon dioxide is produce to give you...
Tuesday, December 16, 2014 at 5:54pm

chemistry
Gasoline sold in Ontario must contain at least 5.00% v/v ethanol? How much gasoline contains 1.50 L of ethanol? my answer is 22.5 ml is this correct
Tuesday, December 16, 2014 at 5:51pm

chemistry
an ice cube has a mass of 4.3g and a mass of 5.0mL it is placed in a 30mL of oil that has a mass of 27 g will the ice cube float or sink in the oil
Tuesday, December 16, 2014 at 5:07pm

Chemistry
Find the molar concentration of 57.9 g of potassiuum chlorate dissolved in 975 mL of water my work c=nv (57.9/122.55)(975ml) and i got 460 is this correct
Tuesday, December 16, 2014 at 4:32pm

Chemistry (Solutions)
Since 1991, house paint produced in Canada must contain no more than 600 ppm of lead. What is the maximum mass of lead permitted ion a 2.50 kg can of paint
Tuesday, December 16, 2014 at 4:26pm

Chemistry Honors
What mass of calcium bromide is needed to prepare 150.0 mL of a 3.50 M solution? (Assume that the molecular weight of CaBr2 is 200.618 g/mol) A. 105 g B. 100.42 g C. 0.105 g D. 103.35 g
Tuesday, December 16, 2014 at 3:59pm

Chemistry Honors
What volume of a 0.50 M MgSO4 solution will be needed to prepare 100.0 mL of a 0.20 M MgSO4 solution? A.250 mL B.100 mL C.0.250 mL D.40.0 mL
Tuesday, December 16, 2014 at 3:57pm

Chemistry Honors
If water, a polar molecule, is combined with another polar molecule, what can be said about the substance added to the water? A. The solubility can not be determined by only knowing the polarity. B.It is soluble in water only if the water is poured over it. C.It is insoluble ...
Tuesday, December 16, 2014 at 3:56pm

Chemistry Honors
Arthur is performing a lab which requires a 0.2 M solution of calcium hydroxide. However, the only calcium hydroxide solution available has a concentration of 0.5 M. How can Arthur dilute the 0.5 M solution to make 10 mL of a 0.2 M solution? A.He needs to add 2.5 mL of the 0.5...
Tuesday, December 16, 2014 at 3:55pm

Chemistry
Aluminum metal crystallizes in a face centered cubic lattice. If each Al atom has a radius of 1.43 A what is the density of aluminum metal? I'm not sure how to go about this. I know that eventually I will use V=l^3, but I'm not sure how to get there. I also know that ...
Tuesday, December 16, 2014 at 2:59pm

general chemistry
The density of a gas is 1.96 g L–1 at 1.00 atm and 0 °C. What is the density of this gas at 0.855 atm and 25.0 C?
Tuesday, December 16, 2014 at 1:32pm

chemistry
(iii) If the chemist wants to prepare 5.00 litres of the stock solution from concentrated H2SO4 , which is 18.0M, what volume of concentrated acid should be used?
Tuesday, December 16, 2014 at 10:19am

Chemistry
A 7.65 g sample of potassium chlorate,KClO3, was heated to decompose all the oxygen. It was found that 2.25 L of oxygen was collected over water at 25.00degreesC and 1.00 atm of pressure. The vapor pressure of water at that temperature is 23.8 mm Hg. How many moles of oxygen ...
Tuesday, December 16, 2014 at 1:57am

Chemistry
The oscillation of electrons in an antenna is an example of which type of radiation/waves/rays? A. Radio waves B. Infrared rays C. Microwaves D. VLF radiation
Tuesday, December 16, 2014 at 12:13am

chemistry
Which of the following spectroscopies is/are suitable for studying materials on surfaces? A. IR and UV/V B. UV/V C. NMR D. XPS and UPS
Monday, December 15, 2014 at 11:50pm

Chemistry
Which of the following is an example of sp3d2 hybridization? A. C2H6 B. IF7 C. PCl5 D. SF6
Monday, December 15, 2014 at 11:39pm

Chemistry
If a 40 gram sample of radioactive isotope was present at 4pm, but a 5 gram sample remained at 4:30 pm, what is the half-life in minutes?
Monday, December 15, 2014 at 11:03pm

basic chemistry
If 0.50 mol of Na3PO4 is mixed with 0.30 mol of BaCl2, the maximum number of moles of barium phosphate which can be formed is: How do i set up the problem?
Monday, December 15, 2014 at 11:02pm

Chemistry
2HCl+Pb(NO3)2---> PbCl2 (s)+2HNO3 Can you please tell why this is not an acid base reaction?
Monday, December 15, 2014 at 9:57pm

general chemistry
Which produces the greatest number of ions when one mole dissolves in water? (A) NaCl (B) NH4Cl C) NH4NO3 (D) Na2SO4
Monday, December 15, 2014 at 9:25pm

general chemistry
If 1.0 g samples of each compound were dehydrated, which sample would lose the greatest mass of water? Molar Masses: LiCl* H2O= 60. g mol–1 MgSO4* H2O= 138. g mol–1 FeSO4*H2O= 170. g mol–1 SrC2O4*H2O=194. g mol–1
Monday, December 15, 2014 at 9:23pm

Chemistry
How do you know that a given reaction is not an acid base reaction? (apart from the fact that it should have an acid and a base and it should be a double displacement reaction)? I mean I know acids have protons (H+) and bases have hydroxides (OH-) but there are so many other ...
Monday, December 15, 2014 at 9:11pm

Chemistry
2C2H6+702---->4CO2+6H20 DELTAH= -3120.6 kJ/mol What mass of ethane must be combusted in order to heat 366 g of water from 25 degree celcius to 100 degree celcius? Assume the heat transfer is 100% efficient. a)44.1 g b) .903g c) 3.61g d) 2.21 g Should I approach this problem...
Monday, December 15, 2014 at 8:56pm

chemistry
Which statement best describes what must occur for two atoms to combine to form a chemical bond? A. The electrons of one nucleus must transfer to the nucleus of the second atom for a chemical bond to form. B. The repulsive forces of both nuclei must overcome their attractive ...
Monday, December 15, 2014 at 8:54pm

chemistry
Find the molar concentration of 57.9 g of potassium chlorate dissolved in 975 mL of water
Monday, December 15, 2014 at 8:14pm

chemistry
What mass of sodium hydroxide pellets must be poured into a waste drum containing 20.0 L o 3.0 mol/L sulphuric acid to completely neutralize the waste acid solution? Write a balanced chemical equation for this reaction. okay, so here is the work I already did my balanced ...
Monday, December 15, 2014 at 8:05pm

Chemistry
What is an ionic solid? A. One positive ion and one negative ion bonded to form a solid B. Many nonmetal atoms bonded together to form a solid C. Many positive and negative ions bonded to form a solid D. Many metal atoms bonded together to form a solid I believe the answer is ...
Monday, December 15, 2014 at 8:04pm

chemistry
since 1991, house paint produced in Canada must contain no more than 600 ppm of lead. What is the maximum mass of lead permitted ion a 2.50 kg can of paint?
Monday, December 15, 2014 at 8:00pm

chemistry
gasoline sold in ontario must contain at least 5.00% v/v ethanol? How much gasoline contains 1.50 L of ethanol
Monday, December 15, 2014 at 7:05pm

chemistry
write a chemical reaction for lead2 nitrate + sodium iodide ->
Monday, December 15, 2014 at 6:26pm

chemistry
In the Bohr model, which is the lowest energy state available for an electron? A. nth B. excited state C. first state D. ground state Im thinking the answer is c or d.
Monday, December 15, 2014 at 6:16pm

Chemistry
The heat of combustion of benzene, C6H6, is -41.74 kJ/g. Combustion of 3.65 of benzene causes a temperature rise of 4.41 C^o in a certain bomb calorimeter. What is the heat capacity of this bomb calorimeter? (kJ/C^o) So, I what I did was I multiplied -41.74 kJ/g and 3.65 to ...
Monday, December 15, 2014 at 6:02pm

chemistry(ppm parts per million)
How would i calculate 2.34 mg x 10^6 divided by 3.50 kg
Monday, December 15, 2014 at 5:35pm

chemistry
A 14 karat gold alloy contains 58% m/m gold. How much of this alloy can a jeweler make using 50.0 g of pure gold?
Monday, December 15, 2014 at 5:13pm

chemistry(solutions)
What is the % w/v of 13.2 g of salt dissolved in 264 mL of solvent?
Monday, December 15, 2014 at 4:17pm

Chemistry
I'm stumped 4ko2 + 2co2 ----2k2co3 + 3o2 What mass of k02 in grams is required to react with 8.90 l at 22.0 c and 767 mm hg? Please help thank you
Monday, December 15, 2014 at 2:54pm

chemistry
If your car gets 21.4 mpg, how many L of CO2, will you release into the atmosphere, if you drove the 1280miles from Towson University to Key West Florida for a much needed break after taking Chemistry 121? Assume 1.05atm and 17.0C. What would your carbon load be in lbs (lbs of...
Monday, December 15, 2014 at 2:33pm

Chemistry
Which electron would have the highest ionization energy for an oxygen atom? A. 2nd B. 1st C. 5th D. 6th If it is the highest I was guessing b or d.
Monday, December 15, 2014 at 2:06pm

chemistry
If your car gets 21.4 mpg, how many L of CO2, will you release into the atmosphere, if you drove the 1280miles from Towson University to key West Florida for a much needed break after taking Chemistry 121? Assume 1.05atm and 17.0C. What would your carbon load be in lbs (lbs of...
Monday, December 15, 2014 at 1:57pm

chemistry
If your car gets 21.4 mpg, how many L of CO2, will you release into the atmosphere, if you drove the 1280miles from Towson University to key West Florida for a much needed break after taking Chemistry 121? Assume 1.05atm and 17.0C. What would your carbon load be in lbs (lbs of...
Monday, December 15, 2014 at 1:54pm

chemistry
A. Orbital shape B. Orientation in the orbital C. Main energy level D. Electron spin
Monday, December 15, 2014 at 1:54pm

chemistry
Under standard conditions for all concentrations, the following reaction is spontaneous at 25 ¢XC with EO = 0.16 V. + - 02 (g) + 4 H (aq) + 4 Br (aq) -+ 2 H20 (I) + 2 Br2 (1) If [H+] is a?justed by adding a buffer of 0.10 M NaOCN and 0.10 M HOCN (Ka = 3.5 x 10 ), what ...
Monday, December 15, 2014 at 12:49pm

chemistry
Malic acid is a weak diprotic organic acid with K1 = 4.0x 10-4 and K2 = 9.0 x 10-6. (a) Letting the symbol H2A represent malic acid, write the chemical equations that represent K1 and K2 . Write the chemical equation that represents K] xK2 . (b) Qualitatively describe the ...
Monday, December 15, 2014 at 12:46pm

Chemistry 120
Calculate the pH of aqueous solution 0.0000019 M KOH
Monday, December 15, 2014 at 12:45pm

chemistry
What is an ionic solid? A. One positive ion and one negative ion bonded to form a solid B. Many nonmetal atoms bonded together to form a solid C. Many positive and negative ions bonded to form a solid D. Many metal atoms bonded together to form a solid I believe the answer is ...
Monday, December 15, 2014 at 12:30pm

Chemistry
What is product form when 2-bromobutane reacts with potassium cyanide in ethanol?
Monday, December 15, 2014 at 12:00pm

Chemistry
A compound D, CH3CHCLCH2CH3 was boiled under reflux for some time with dilute NaOH solution.. Dilute nitric acid was then added to the mixture, followed by dilute silver nitrate solution. A Few drops of concentrated ammonia solution were then added. What observation were ...
Monday, December 15, 2014 at 11:56am

Chemistry
Outline the prepartion of 2-chlorobutane from an alcohol?
Monday, December 15, 2014 at 11:43am

Chemistry
Naturally occurring magnesium consists of Magnesium-24 (23.9850 amu; 78.99%), Magnesium-25 (24.9858 amu), and Magnesium-26 (25.9826 amu). Using the average atomic mass from the periodic table, calculate the closest percent abundance of Magnesuim-26. a) 29.30% b) 8.993% c) 10....
Monday, December 15, 2014 at 10:56am

chemistry
For an atom of sulfur, which electron would require the least amount of energy to remove from the atom? A. 3s2 B. 1s1 C. 3p1 D. 3p4 I think the answer is c or d, preferring d. What would you go with?
Monday, December 15, 2014 at 1:30am

Chemistry
Last question I'm having trouble with. Predict the oxidation # for astatine. Why?
Monday, December 15, 2014 at 12:38am

Chemistry
What is the difference in a polyatomic ion that has its name end in (-ate) as compared to one with the same central element that ends in (-ite)
Sunday, December 14, 2014 at 11:55pm

Chemistry
Which of the following is an example of quantization? A. The amount of time spent in a classroom B. The number of students in a classroom C. Learning happening in a classroom D. The temperature range in a classroom I know I asked this question but I would this paragraph. Is it...
Sunday, December 14, 2014 at 11:54pm

Chemistry
Suppose a student used 28.4 ml of 0.100 M NaOH solution to neutralize the 25.0 ml of the lemon juice sample which contains citric acid (H3A)in it. H3A + 3NaOH -----> Na3A + 3H2O Molar mass of citric acid = 192.2 g/mole a)What is the molarity(M)of citric acid(H3A)in lemon ...
Sunday, December 14, 2014 at 11:46pm

chemistry
A 27.00mL sample of an H2SO4 solution of unknown concentration is titrated with a 0.1422M KOH solution. A volume of 40.22mL of KOH was required to reach the equivalence point. What is the concentration of the unknown H2SO4 solution? Any help would be greatly appreciated. (:
Sunday, December 14, 2014 at 11:36pm

Chemistry
Why is it hard to use the periodic table to predict the oxidation #'s of the transition elements?
Sunday, December 14, 2014 at 11:32pm

chemistry
Which of the following is an example of quantization? A. The amount of time spent in a classroom B. The number of students in a classroom C. Learning happening in a classroom D. The temperature range in a classroom I strongly believe the answer is A. Any objections.
Sunday, December 14, 2014 at 7:59pm

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