Friday
December 19, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Post a New Question | Current Questions

chemistry
Iodine(I2)is a solid molecular compound at room temperature. Predict its solubility in liquid water(H2O)and in liquid cyclohexane(C6H12) at room temperature respectively and provide explain for your answer.
Sunday, December 14, 2014 at 12:18am

chemistry
The solubility of NaCl at 17 celsisus degrees is 39 g per 100 ml water. If 83 g of NaCl is dissolved in 250ml of water at the same temperature, the resulting solution is: a)unsaturated; b)saturated; c)supersaturated
Saturday, December 13, 2014 at 11:39pm

Chemistry
Consider the thermal decomposition of potassium chlorate. 2 KClO3 (s)-----> 2 KCl (s) + 3 O2 (g) A mixture containing KCl and KClO3 weighing 1.80 g was heated producing 1.40 x 102 mL of O2 gas at STP. What percent of the original mixture was KClO3? Is this how I should ...
Saturday, December 13, 2014 at 9:02pm

chemistry
How much energy (in kilojoules) is needed to heat 4.00g of ice from -11.0∘C to 21.5∘C? The heat of fusion of water is 6.01kJ/mol, and the molar heat capacity is 36.6 J/(K⋅mol) for ice and 75.3 J/(K⋅mol) for liquid water.
Saturday, December 13, 2014 at 7:20pm

chemistry
Suppose 100 mL of NO at STP is mixed with 400 mL of O2 at STP. 2 NO (g) + O2 (g)---> 2 NO2 (g) After the reaction goes to completion, what is the partial pressure of NO2 in the resulting mixture of gases at STP? I know the relation between pressure and volume is P1V1=P2V2, ...
Saturday, December 13, 2014 at 2:38pm

chemistry
What is periodicity.
Saturday, December 13, 2014 at 2:09pm

Chemistry
how many milliliters of 4 M h2so4 are needed to react completely with 23.7g of Bao2
Saturday, December 13, 2014 at 9:52am

chemistry
Which term has the same numerical value for the forward reaction as it has for the reverse reaction, but with opposite sign? a. ^E ( delta E) b. Ea1 c. Ea’ d. Ea2
Saturday, December 13, 2014 at 4:58am

Chemistry
How much of a 5.2M sucrose solution should you use to make 81.0mL of a 0.040M solution?
Saturday, December 13, 2014 at 1:11am

Chemistry
Are there any structural isomers of hydrocarbons from methane to decane have 3 stereogenic C atoms? (i know that there are none for decane itself, but I am wondering about the others before it.) Thanks in advance!
Saturday, December 13, 2014 at 12:44am

Chemistry
Red light has a wavelength of 700 nm and a frequency of 4.3 x 1014 s-1. What is the energy of a single photon of red light? A. 2.85 x 10-34 J B. 2.85 x 1019 J C. 2.85 x 10-20 J D. 2.85 x 10-19 J
Friday, December 12, 2014 at 10:45pm

chemistry
In which unit is the wavelength of an electromagnetic wave commonly measured? A. J B. nm C. s–1 D. kg All most positive it is b but I just wanted to make sure.
Friday, December 12, 2014 at 10:34pm

Chemistry
What does the photoelectric effect show about the connection between light and electrons? A. Light can remove electrons from atoms. B. Electrons are composed of light. C. Light is composed of electrons. D. It takes 2 photons of light to cause 1 electron to begin flowing.
Friday, December 12, 2014 at 8:58pm

chemistry
what mass of water is necessary to prepare 150.0g of 1.30% saline solution
Friday, December 12, 2014 at 5:03pm

chemistry
What mass of solution contains 15.0g of sulfuric acid in a 20.0% solution
Friday, December 12, 2014 at 5:02pm

Chemistry
14.6 mL of hydrochloric acid is completely neutralized by 25.0 mL of 1.40 M sodium hydroxide, what was the hydrochloric acid mass percent (m/m) before the titration? (Density of hydrochloric acid is 1.02 g/cm3)
Friday, December 12, 2014 at 3:08pm

Chemistry
Acetylene gas, C2H2, reacts with oxygen according to the following equation. If 46.0 g of acetylene reacts with 100.0 g of oxygen, what is the theoretical yield of heat produced from the reaction? ___ C2H2(g) + ___ O2(g) → ___ CO2(g) + ___ H2O(g); balanced reaction ...
Friday, December 12, 2014 at 3:04pm

Chemistry
The mass/volume percent of a sodium sulfate and water solution is 12.0% m/v. If the density of the solution 1.22 g/mL, what is the molarity of the solution?
Friday, December 12, 2014 at 2:58pm

chemistry
A sodium atom when excited gives off two very specific wavelengths of visible light. What does this tell us about sodium? A. There are two principal electron transitions in sodium. B. There are two electrons in a sodium atom. C. A sodium atom has its electrons in two energy ...
Friday, December 12, 2014 at 2:40pm

Chemistry
A spoon of sterling silver is 92.5% silver by mass and the rest is made of other metals, usually copper. If the spoon contains 0.557 mol of silver, what is the mass of the spoon?
Friday, December 12, 2014 at 12:15pm

Chemistry
My teacher gave us a packet with many questiona on it for homework. I was able to figure all 44 questions except the following 2.... Help!?!?! 9. "In order to have 1.00 mole of gas fit in a box that measures 1.30 dm x 2.40 dm x 5.83 dm at 1.00 atm, what must the ...
Friday, December 12, 2014 at 9:05am

Chemistry
A gas occupies 21.0 L at 2.00 atm pressure and 27oC. Calculate its volume at STP.
Friday, December 12, 2014 at 6:19am

Chemistry
0.250 moles of HCL and 0.100 moles of acetic acid are mixed in 0.365 moles of water. Determine the following: [CH3COOH], [CH3COO^-], pH and pOH. Ka=1.8E-5. Calculate the pH of 0.05M CH3COO-Na+ . Plz show me step by step, really confused right now.
Friday, December 12, 2014 at 4:55am

Chemistry
If NaCl has a solubility of 36.0 g in 100 g of H2O at 20 °C, how many moles of water are needed to prepare a saturated solution containing 0.263 mol of NaCl at 20 °C?
Friday, December 12, 2014 at 1:39am

Chemistry
How many milliliters of 0.150M BaCl2 are needed to react completely with 40.0mL of 0.260M Na2SO4?
Friday, December 12, 2014 at 12:43am

chemistry
Calculate the amount of heat required to heat a 4.0kg gold bar from 20∘C to 61∘C. Specific heat capacity of gold is 0.128 J/g∘C. How do we figure this out?
Friday, December 12, 2014 at 12:36am

chemistry
What is the molality of 67.1g of Nano3 in 2.5l of water i get the molar mass of nano3 and divide it by the 67.1g and multipy it by 2.5l
Friday, December 12, 2014 at 12:35am

chemistry
What is the difference between the ionization energy of inner-shell electrons and the ionization energy of outer-shell electrons? A. The ionization energy of inner-shell electrons is less than the ionization energy of outer-shell electrons. B. They are equal to each other. C. ...
Friday, December 12, 2014 at 12:13am

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 What is the definition of quantization
Friday, December 12, 2014 at 12:12am

chemistry
When calcium chloride and ammonium phosphate are mixed, an insoluble precipitate of calcium phosphate forms and falls out of solution. After careful analysis of the purified precipitate, 8.16 * 10^25 atoms of calcium are found in the solid. How many other atoms are in the ...
Thursday, December 11, 2014 at 11:17pm

chemistry
Which statement describes the principal quantum number (n)? A. The quantum number that indicates the subshell occupied by an electron B. The quantum number that indicates the energy level of the electron C. A subdivision of an energy level in an atom D. The probability of ...
Thursday, December 11, 2014 at 11:13pm

chemistry
What does the fact that a blackbody can absorb light only in specific-sized "packets" say about light? A. It has no mass. B. It is composed of electrons. C. It is composed of atoms. D. It is quantized. I have no idea what the answer is
Thursday, December 11, 2014 at 10:57pm

chemistry
calculate the energy required to raise the temp of 72g of water from 50c tp 150
Thursday, December 11, 2014 at 10:57pm

Chemistry
Hydrogen chloride gas can be prepared by the following reaction: 2NaCl(s) + H2SO4(aq) --> 2HCl(g) + Na2SO4(s) How many grams of HCl can be prepared from 2.00 mol H2SO4 and 2.56 mol NaCl?
Thursday, December 11, 2014 at 10:50pm

Chemistry
Hydrogen chloride gas can be prepared by the following reaction: 2NaCl(s) + H2SO4(aq) --> 2HCl(g) + Na2SO4(s) How many grams of HCl can be prepared from 2.00 mol H2SO4 and 2.56 mol NaCl?
Thursday, December 11, 2014 at 10:48pm

Chemistry
Hydrogen chloride gas can be prepared by the following reaction: 2NaCl(s) + H2SO4(aq) --> 2HCl(g) + Na2SO4(s) How many grams of HCl can be prepared from 2.00 mol H2SO4 and 2.56 mol NaCl?
Thursday, December 11, 2014 at 10:48pm

Chemistry
1. Calculate the concentration of H3O+, HC2O4-1, and oxalate ion (C2O42-) in a 0.175 M solution of oxalic acid (C2H2O4). [For oxalic acid, Ka1 = 6.5 ´ 10-2, Ka2 = 6.1 ´ 10-5.]
Thursday, December 11, 2014 at 10:43pm

Chemistry
All electromagnetic energy (light), including gamma rays through radio waves, has what in common? A. Speed B. Wavelength C. Frequency D. Energy E. Amplitude I think a
Thursday, December 11, 2014 at 10:42pm

chemistry
is finding the molality and molarity the same concept
Thursday, December 11, 2014 at 10:37pm

chemistry
What does electron affinity depend on? A. Both the effective nuclear charge and the number of shells in the atom containing electrons B. Attraction between the protons and neutrons C. Only the effective nuclear charge D. Attraction between the valence electrons and core ...
Thursday, December 11, 2014 at 10:30pm

Chemistry
Core electrons shield what from the pull of the nucleus? A. Identical electrons B. Valence electrons C. Neutrons D. Protons I was thinking d or a.
Thursday, December 11, 2014 at 10:26pm

chemistry
how much heat is required to raise a 54g sample of water from -20 celsius to 90 celsius explain
Thursday, December 11, 2014 at 10:22pm

chemistry
How do u tell of a solute is polor or non polar based on what
Thursday, December 11, 2014 at 9:43pm

chemistry
how many moles of solute are contained in 18.5ml 2.5m CaCL2
Thursday, December 11, 2014 at 9:22pm

chemistry
What is the molality of 67.1g of Nano3 in 2.5l of water
Thursday, December 11, 2014 at 8:51pm

chemistry
how wud u prepare 1L of a 1.30M aqueous solution of barium sulfide explain
Thursday, December 11, 2014 at 8:48pm

chemistry
how much heat has been absorbed by 2500g of water when its temperature changes from 23c to 27c PLEASE EXPLAin
Thursday, December 11, 2014 at 8:47pm

chemistry
What is the ppm of 4.50mg of ddt in 10kg of seal fat?
Thursday, December 11, 2014 at 8:45pm

chemistry
Increasing pressure does what to solubility. Increasing surface area? increasing temp?
Thursday, December 11, 2014 at 8:44pm

Chemistry
I am doing a lab and broke my glass beaker. Is it of to put 0.1 M hydrochloric acid in a plastic beaker?
Thursday, December 11, 2014 at 6:10pm

Chemistry
Methane reacts with oxygen to produce carbon dioxide, water and heat. If the percent yield of the reaction is 90.0%, how many grams of methane must be burned to produce 150.0 kJ of energy? ___ CH4 (g)+ ___ O2 (g) → ___ CO2 (g) + ___ H2O(g) + 802 kJ
Thursday, December 11, 2014 at 5:04pm

Chemistry, Vapor Pressure
Select the pair of substances in which the one with the higher vapor pressure at a given temperature is listed first. 1. C7H16, C5H12 2. CCl4, CBr4 3. H2O, H2S 4. CH3CH2OH, CH3-O-CH3 5. Xe, Kr
Thursday, December 11, 2014 at 4:29pm

Chemistry
After adding a hot piece of titanium to a cup containing 300.0 mL of 30.0 °C water, the final temperature of the solution is 41.2 °C and the final volume of the solution is 400.0 mL. The density of titanium is 4.50 g/cm3. If no energy is lost to the surroundings, what ...
Thursday, December 11, 2014 at 3:13pm

chemistry
The ?H of the reaction below is -575.13 kJ. Is this reaction spontaneous? 2ZnS + 3O2 + C ? 2SO2 + 2Zn + CO2 A. It is not because the ?H of the reaction is negative. C. It depends on the temperature because the ?H of the reaction is negative and the ?S is negative. D. It ...
Thursday, December 11, 2014 at 3:07pm

chemistry
When 3.2 g of ammonium chloride is dissolved in 75 g of water, the temperature of the solution decreases from 22.8°C to 20.1°C. What is the energy of dissolution of NH4Cl per mole? (The molecular mass of NH4Cl = 53.49 g/mol, and the specific heat of water = 4.18 J/g&...
Thursday, December 11, 2014 at 2:12pm

Chemistry
Calculate the freezing and boiling points of a solution containing 14.9g FeCl3 in 176g water.
Thursday, December 11, 2014 at 12:23pm

chemistry
isotope chromium -51 has a half life of 28 days. If the original sample had a mass of 28.0 grams, what mass of chromium -51 sample remains after 84 days?
Thursday, December 11, 2014 at 10:31am

chemistry
write an equation that describes the equilibrium present in a saturated solution of Cu3(PO4)2 someone please explain to me, thanks!
Thursday, December 11, 2014 at 5:53am

chemistry
write an equation that describes the equilibrium present in a saturated solution of Cu3(PO4)2 someone please explain to me, thanks!
Thursday, December 11, 2014 at 5:53am

chemistry
A solution contains 0.20 M Cl- and 0.20 M SO4^2-. a) identify a cation that could be added to the solution to give a precipitate with only one of these anions. MY answer: Cu+ b) write the net ionic equation for the precipitation reaction in part a) MY answer: Cl^- + Cu^+ ==>...
Thursday, December 11, 2014 at 5:51am

chemistry
Q) in the reaction, 210kj of heart energy is used to form 3.0 miles of hydrogen. Calculate how much heat energy is needed to make 1000kg of hydrogen.
Thursday, December 11, 2014 at 2:28am

Chemistry
Benzene, C6H6, consists of six member ring of sp2 hybridized p orbital. How many (pi)_2p bonding, anti bonding, and nonbonding molecular orbitals exist for benzene?
Thursday, December 11, 2014 at 12:21am

Chemistry
Calculate the percent purity of a sample of zinc metal if 325 mL of hydrogen gas is collected by water displacement at a temperature of 22.0 C and an atmospheric pressure of 745.0 mm Hg when 1.12 g of the sample is reacted with excess HCl: Zn + 2 HCl = H2 + ZnCl2. The vapor ...
Thursday, December 11, 2014 at 12:10am

Chemistry
When 3.2 g of ammonium chloride is dissolved in 75 g of water, the temperature of the solution decreases from 22.8°C to 20.1°C. What is the energy of dissolution of NH4Cl per mole? (The molecular mass of NH4Cl = 53.49 g/mol, and the specific heat of water = 4.18 J/g&...
Wednesday, December 10, 2014 at 10:52pm

Chemistry
How many molecules are in 0.923 mol of selenium tetrabromide?
Wednesday, December 10, 2014 at 8:08pm

Urgent chemistry help
is there anything unusual about how the first elements are named when naming the compound? Is there anything unusual about how the second element is named when naming the compound? Why are the elements in the binary compounds combined in different ratios ( as shown by the ...
Wednesday, December 10, 2014 at 7:39pm

Chemistry
What is the density (in grams per liter) of a gas at STP if 1.97 L of the gas in a bulb at 23.8 °C, and 761.9 mm Hg weighs 0.371 g?
Wednesday, December 10, 2014 at 7:26pm

Chemistry
When treating a patients physicians use an isotonic means that this solution will have the same osmotic pressure as the body fluid such as blood. how many grams of glucose (C6H12O6) is in 100.0 g of H2O in the isotonic glucose solution (5.00% m/m)?
Wednesday, December 10, 2014 at 5:24pm

chemistry
A piece of Cu wire is placed into 1.00L of a saturated solution of silver acetate, AgCH3COO. When all the Ag+ has reacted, 2.00g of Cu has been used. A) Write the net ionic equation for this reaction between Cu and Ag+. B) Calculate the Ksp of AgCH3COO. Thank you!
Wednesday, December 10, 2014 at 4:23pm

chemistry
A sample of nickel is heated to 95.0°C and placed in a coffee-cup calorimeter. If the 50.0 g of water in the calorimeter is initially 22.3°C and warms to 25.4°C, what mass of nickel was heated? (The specific heat of nickel is 0.444 J/°C g and water is 4.18 J/&...
Wednesday, December 10, 2014 at 2:32pm

Chemistry
Adding helium to a balloon increased its volume from 360.9 mL to 3.532 L. If the final number of moles of helium in the balloon is 22.3 mol, what was the initial number of moles of helium in the balloon? Assume the balloon contained only helium initially.
Wednesday, December 10, 2014 at 2:03pm

chemistry
you want to determine the amount of chlorophyll(Molecular weight=893.51g/mol)in a 25ml marine sample.before analysis by UV spectoscopy,2ml of sollution was centrifuged.0.5ml of the supernatant was diluted to 150ml with DI water.the diluted sample was analysed using UV ...
Wednesday, December 10, 2014 at 12:37pm

chemistry
A sample of nickel is heated to 95.0°C and placed in a coffee-cup calorimeter. If the 50.0 g of water in the calorimeter is initially 22.3°C and warms to 25.4°C, what mass of nickel was heated? (The specific heat of nickel is 0.444 J/°C g and water is 4.18 J/&...
Wednesday, December 10, 2014 at 1:02am

Chemistry 2!
consider the following reaction, equilibrium concentrations, and equilibrium constant at a particular temperature. Determine the equilibrium concentration of H2O(g) C2H4(g) + H2O(g) <--> C2H5OH(g) kc= 7.0* 10^3 [C2H4]= 0.010M [C2H5OH]= 1.99M
Wednesday, December 10, 2014 at 12:26am

chemistry
A .523g sample of a mix of Na2co3 and Nahco3, is titrated with .1 HCl requiring 17 ml to reach the phenolphthalein end point and a total of 43.8 ml to reach the methyl orange end point. What is the percent of each of na2co3 and nahco3 in the mixture?
Tuesday, December 9, 2014 at 10:58pm

general chemistry
Copper crystallizes in a face-centered cubic unit cell with an edge length of 362 pm. What is the radius of a Cu atom in pm?
Tuesday, December 9, 2014 at 10:20pm

Chemistry
1.) Can you explain to me how Faraday's Constant works in electrolytic cells? (We did a lab experiment on copper wires and sulfuric acid, collecting H2 gas.) I'm not sure how to answer the question. 2.) Does copper conduct more electricity than platinum? Why or why not?
Tuesday, December 9, 2014 at 10:12pm

general chemistry
Copper crystallizes in a face-centered cubic unit cell with an edge length of 362 pm. What is the radius of a Cu atom in pm? What equation do you use?
Tuesday, December 9, 2014 at 9:40pm

general chemistry
Methanol has a ΔHvap = 35.3 kJ/mol CH3OH. Calculate the change in heat, q, when 50.0 g methanol condenses? Caution! Is q + or -?
Tuesday, December 9, 2014 at 9:30pm

chemistry
How to prepare 250.0 mL of 0.076M NaOH?
Tuesday, December 9, 2014 at 9:26pm

chemistry
What is the entropy change associated with the chemical reaction that occurs when iron oxide is converted to its metal form? Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g) A. Zero B. Positive C. Negative D. Cannot be determined I think the answer is b or c.
Tuesday, December 9, 2014 at 8:16pm

chemistry
The enthalpy of formation of C2H5OH is -238.7 kJ/mol. What information does this reveal about the bonds in the molecule? A. Bond formation in C2H5OH from its elements only occurs in cold temperatures. B. Bond formation in C2H5OH from its elements does not occur. C. Bond ...
Tuesday, December 9, 2014 at 7:20pm

chemistry
The pressure of a gas sample in a rigid container is 810.0 mmHg at 22 oC. What is the pressure, in mmHg, at 50 oC? I have a rough idea on how to solve, but which equation do I use?
Tuesday, December 9, 2014 at 6:59pm

Chemistry
How many liters of stomach acid (pH = 4.000) will be neutralized by a 1.50 g tablet of "Bicar", a commercial tablet which is 50% flavored and 50% NaHCO3? Note that: NaHCO3(s) --> Na+(aq) + HCO3-(aq) and: H+(aq) + HCO3-(aq) --> H20(l) + CO2(g) So far I've ...
Tuesday, December 9, 2014 at 5:57pm

Chemistry
What is the address of the 11 th electron of magnesium? And how do you determine this?
Tuesday, December 9, 2014 at 5:18pm

Chemistry
What are some cons of becoming a pharmacologist?
Tuesday, December 9, 2014 at 5:08pm

chemistry
Suppose a gas sample has a density of 3.68 g/L at STP. What is its density at 25 oC and 19.0 atm?
Tuesday, December 9, 2014 at 4:45pm

Chemistry
How much heat energy, in kilojoules, is required to convert 48.0g of ice at −18.0 ∘C to water at 25.0 ∘C ? Please show all steps. i don't know where to start
Tuesday, December 9, 2014 at 3:58pm

chemistry
Suppose a gas sample occupies 14.9 L at STP. What is its volume at 400 K and 0.87 atm? which equation would you use for this?
Tuesday, December 9, 2014 at 3:46pm

chemistry
The total phosphate concentration in a blood sample is determined by spectrophotometry to be 3.0×10−3 M. The pH of the blood sample is 7.45, What are the concentrations of H2PO4− and HPO42- in the blood? Pka for the phosphate system is 7.198
Tuesday, December 9, 2014 at 3:46pm

Analytical Chemistry
Calculate the ppm of the sodium ions when 2.91 g of sodium triphosphate are added to 2.33 L of solution. I earnestly have no idea how to solve this...
Tuesday, December 9, 2014 at 2:43pm

Chemistry
The rate constant for a second-order reaction is 0.54 M-1s-1. What is the half-life of this reaction if the initial concentration is 0.27 M
Tuesday, December 9, 2014 at 1:44pm

chemistry
Using the following thermochemical data, what is the change in enthalpy for the following reaction? 2H¿(g) + 2C(s) + O¿(g) d C¿HÂOH(l)? C2H5OH(l) + 2O2(g) d 2CO2(g) + 2H2O(l),  DH = -875 kJ C(s) + O¿(g) d CO¿(g),  DH = -394.51...
Tuesday, December 9, 2014 at 11:03am

Organic Chemistry
Cu++ forms a blue-green complex with tetraphenylporphin in a 1:1 ratio. Say you have 100 mL of a 2.0 x 10^-4 solution of the Tetraphenylporphin. Exactly what weight of CuCl2 must be added to the solution to insure complete complexation without any excess cupric chloride ...
Tuesday, December 9, 2014 at 10:51am

Chemistry
Dinitrogen tetraoxide decomposes to give nitrogen dioxide. Calculate the equilibrium concentration of NO2 at 100oC if the equilibrium constant is 0.200 and [N2O4] = 0.800M. N2O4(g) ¡ê 2 NO2(g)
Tuesday, December 9, 2014 at 9:57am

Chemistry
A liquid has a delta(Hvap) of 35.5 kJ/mol and a boiling point of 122 C at 1.00atm. What is its vapor pressure at 113 C?
Tuesday, December 9, 2014 at 7:43am

Chemistry
At a given temperature and pressure how does the magnitude of the heat of vaporization of a substance compare with that of its heat of condensation?
Tuesday, December 9, 2014 at 7:10am

Chemistry - University
Pentane (C5H12) and hexane (C6H14) form an ideal solution. The vapour pressure of pentane at 25oC is 511 mmHg and that for hexane is 150 mmHg. A solution is prepared by mixing pentane (density = 0.63 g/mL) and hexane (density = 0.66 g/mL). The mole fraction of hexane in the ...
Tuesday, December 9, 2014 at 6:27am

chemistry
Why an atom is electrically neutral ?
Tuesday, December 9, 2014 at 12:15am

Chemistry
Which solution has the lower freezing point? 11.0 g of methanol in 100. g of water OR 22.0 g of ethanol in 200. g of water?
Monday, December 8, 2014 at 11:59pm

Pages: <<Prev | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | Next>>

Post a New Question | Current Questions

Homework Help: Science

Search
Members