Wednesday
December 17, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Post a New Question | Current Questions

Chemistry
H2C2O4(aq) + 2 NaOH(aq) → Na2C2O4(aq) + 2 H2O(l) If I use 0.025 moles of NaOH to neutralize the Oxalic acid, how many moles of Oxalic acid are there?
Tuesday, October 21, 2014 at 12:09am

chemistry
A flask that can withstand an internal pressure of 2511 torr, but no more, is filled with a gas at 21.0°C and 758 torr and heated. At what temperature will it burst? i used P1/x=P2/T2 and got 69.6 degrees Celsius. what is wrong
Monday, October 20, 2014 at 10:57pm

Chemistry
How long (in minutes) must a 5.40 A current be passed through an aqueous solution of zinc nitrate to deposit 87.5 g Zn?
Monday, October 20, 2014 at 10:43pm

Easy Chemistry
How long (in minutes) must a 5.40 A current be passed through an aqueous solution of zinc nitrate to deposit 87.5 g Zn?
Monday, October 20, 2014 at 10:24pm

chemistry
H2(g) + Cl2(g) HCl(g) Consider the unbalanced equation above. 3.95 L of H2 and 1.00 L of Cl2 are reacted under the same conditions of temperature and pressure. (a) How many liters of HCl will be produced? (b) How many liters of reactant are in excess? i found part a to be 2.00...
Monday, October 20, 2014 at 10:15pm

chemistry
Which of the following half-reactions would occur at the anode of an electrochemical cell? A. H+(aq) + Cl− (aq) → HCl(aq) B. Li+(aq) + e− → Li(s) C. Cu+(aq) + e− → Cu(s) D. Cu(s) → Cu+(aq) + e−
Monday, October 20, 2014 at 9:39pm

Bio- Chemistry
How can you identify the difference between an plant and animal cell. What structures (you should have at least 2) should you look for in each in order to tell the difference?
Monday, October 20, 2014 at 8:54pm

Chemistry
When 2.25 g of sodium hydroxide (NaOH) was dissolved in 150.00 g of water a value of 11.00oC was obtained for ΔT. 1. Calculate the molarity of the sodium hydroxide solution. 2. Calculate the value (calories) for the heat of solution of 2.25 g of NaOH. 3. Calculate the ...
Monday, October 20, 2014 at 8:48pm

Chemistry
Match the following units to their correct property: A. Density of Solution B. Heat Capacity C. Molarity D. Specific Heat 1. J/g•oC 2. J/oC 3. g/ml 4. cal/g•oC
Monday, October 20, 2014 at 8:47pm

chemistry
Describe the difference between a prokaryote and a eukaryote. Be specific about the description of each type of cell (i.e. tell which cell type has which characteristics.)
Monday, October 20, 2014 at 8:39pm

chemistry
Why are half-reactions used in redox reactions? A. They make it easier to keep track of spectator ions in the reaction. B. They make it easier to see the oxidation and reduction parts of the reaction separately. C. They make it possible to neglect the electrons that are being ...
Monday, October 20, 2014 at 7:23pm

chemistry
What is the difference between a galvanic cell and an electrolytic cell? A. A galvanic cell converts reduction reactions into an electrolytic cell, and an electrolytic cell converts oxidation reactions into a galvanic cell. B. A galvanic cell converts oxidation reactions into ...
Monday, October 20, 2014 at 6:28pm

Chemistry
An aqueous solution of ammonium nitrite decomposes when heated to give off nitogen gas and water. This reaction can be used to prepare pure nitrogen gas. How many grams of ammonium nitrite must have reacted if 3.75 liters of nitrogen gas was colleced over water at 25˚C ...
Monday, October 20, 2014 at 5:39pm

science-chemistry
An aqueous solution of ammonium nitrite decomposes when heated to give off nitogen gas and water. This reaction can be used to prepare pure nitrogen gas. How many grams of ammonium nitrite must have reacted if 3.75 liters of nitrogen gas was colleced over water at 25˚C ...
Monday, October 20, 2014 at 5:38pm

Chemistry
An aqueous solution of ammonium nitrite decomposes when heated to give off nitrogen gas and water. This reaction can be used to prepare pure nitrogen gas. How many grams of ammonium nitrite must have reacted if 3.75 liters of nitrogen gas was collected over water at 25˚C ...
Monday, October 20, 2014 at 5:36pm

chemistry
The heat of solution of ammonium nitrate is 26.2 kJ/mol, and a 7.315 g sample of NH4NO3 is added to 40.0 mL of water in a constant pressure calorimeter initially at 25.2°C, what is the final temperature reached by the solution? (The specific heat of water = 4.184 J/g•...
Monday, October 20, 2014 at 5:26pm

Chemistry
How would the empirical formula of copper (II) sulfate be affected if some of the sample sticks to the stirring rod?
Monday, October 20, 2014 at 5:22pm

Chemistry
Po-210 Ia an alpha emitter with a half-life of 138 days. how many grams of Po-210 remain after 552 days if the sample initially contained 5.80g of Po-210?
Monday, October 20, 2014 at 4:27pm

chemistry
How many aluminum atoms are in 3.78 g\rm g of aluminum?
Monday, October 20, 2014 at 4:19pm

Chemistry
The following galvanic cell at standard conditions has a potential of 0.03 V: Ag+(aq) + Fe2+(aq) → Fe3+(aq) + Ag(s). What would be the effect of increasing the concentration of Ag+? A. The cell potential will decrease. B. The cell potential will increase. C. The cell ...
Monday, October 20, 2014 at 4:03pm

Chemistry
What mass KCl is needed to precipitate AgCl from 15.0 mL of .200 M AgNO3
Monday, October 20, 2014 at 3:58pm

Chemistry
The following galvanic cell at standard conditions has a potential of 0.03 V: Ag+(aq) + Fe2+(aq) → Fe3+(aq) + Ag(s). What would be the effect of increasing the concentration of Ag+? A. The cell potential will decrease. B. The cell potential will increase. C. The cell ...
Monday, October 20, 2014 at 2:56pm

Easy Chemistry
What is the oxidation half-reaction for Mg(s) + ZnCl2(aq) MgCl2(aq) + Zn(s)? A. Zn(s) Zn2+ + 2e- B. Zn2+ + 2e- Zn(s) C. Mg(s) Mg2+ + 2e- D. Mg2+ + 2e- Mg(s)
Monday, October 20, 2014 at 2:26pm

Easy Chemistry
Which of the following processes uses a galvanic cell? A. Electroplating silver metal onto a teapot B. Purification of metals such as copper from their metal ores C. Electrolysis of sodium chloride D. Operation of a portable music player
Monday, October 20, 2014 at 1:54pm

Chemistry
the human body is 60% water by weight, how much water in liters does a 196lb man contain?
Monday, October 20, 2014 at 1:29pm

chemistry
Can someone help me with Chemistry Homework Due Tomorrow, Its about the Electrolysis of Hydrochloric Acid Practical we did and I Have to write a summary and I dont get what we did Y10 GCSE Higher Tier
Monday, October 20, 2014 at 1:14pm

chemistry
When 25.0 ml of 0.500M HCI is added to 25.0ml of 0.500M KOH in a coffee cup calorimeter at 23.50C, the temperature rises to 30.17C. Calculate delta H of this reaction ( assume density of solution = 1g/ml)
Monday, October 20, 2014 at 12:46pm

chemistry
one piece of copper metal at 105 C has twice the mass of another copper piece at 45 C. What is the final temperature if these two pieces are placed in a calorimeter. Specific heat of copper is 0.387 J/g.K.
Monday, October 20, 2014 at 11:34am

chemistry
MgCO2(s)-> MgO9(s) + CO2(g) A. what is delta H reaction when 3.35 mol of CO2 react with excess MgO? B. What is delta H reaction when 305.5 g of MgCO3 decomposes.
Monday, October 20, 2014 at 11:32am

Chemistry
Estimate the amount of 1.0m NaOH in ml required to neutralize 5.0g of KHP
Monday, October 20, 2014 at 9:38am

Chemistry
You need to make 500mls of a 7percent bovine serum solution
Monday, October 20, 2014 at 7:33am

Chemistry need help
Write the formula of the anion present (i.e. anions are charged; do not write compounds) in these unknowns as indicated by these test results. 1) An unknown was mixed with ammonium hydroxide and then barium chloride. Nothing happened. A fresh portion was mixed with nitric acid...
Monday, October 20, 2014 at 2:56am

Chemistry need help please!!!!
Write the formula of the anion present (i.e. anions are charged; do not write compounds) in these unknowns as indicated by these test results. 1) An unknown solution was treated with ammonium hydroxide and then with barium chloride. A precipitate formed. The precipitate did ...
Monday, October 20, 2014 at 1:22am

chemistry
Determine how many kg of benzoic acid would dissolve in 1.00 Liter of water at 50 degrees C? My work: 1.00/50C X 1000g/1L X .001kg/1g= 1kg/50C
Sunday, October 19, 2014 at 11:30pm

Chemistry
Consider the following reaction. 2 HCl(aq) + Ba(OH)2(aq) BaCl2(aq) + 2 H2O(l) ΔH = -118 kJ Calculate the heat when 114.8 mL of 0.500 M HCl is mixed with 300.0 mL of 0.400 M Ba(OH)2. Assuming that the temperature of both solutions was initially 25.0°C and that the ...
Sunday, October 19, 2014 at 10:17pm

chemistry
write the balanced molecular and net iconic equations for the reaction between aluminium metal and silver nitrate. Identify the oxidation and reduction half-reaction
Sunday, October 19, 2014 at 9:55pm

Chemistry
1. When solid copper metal reacts with nitric acid, the products include copper (II) ion and nitrogen monoxide gas. If 11.99 g of solid copper are reacted with 153 mL of 0.322 M HNO3, how many liters of nitrogen monoxide will be produced? 2. When solid copper metal reacts with...
Sunday, October 19, 2014 at 7:02pm

Chemistry
In a test tube, 1.0mL of 0.10 M lead(II) nitrate and 10 mL of 1.0M sodium chloride are mixed. Calculate the theoretical mass of solid formed
Sunday, October 19, 2014 at 6:54pm

AP Chemistry
What is the change of enthalpy associated with the combustion of one mole of pentane? C5H12 + 8O2 ¨ 5CO2 + 6H2O I'm very confused, Please help!
Sunday, October 19, 2014 at 6:14pm

Chemistry
Determine the number of grams of oxygen in 13 grams of calcium acetate.
Sunday, October 19, 2014 at 5:44pm

Chemistry
What would be the problem with determining a IR spectrum on a liquid whose boiling point is 30 degrees celcius
Sunday, October 19, 2014 at 4:47pm

chemistry
When river water cools on a winter day, the level of dissolved oxygen gas in the water available for fish to breathe tends to _____________
Sunday, October 19, 2014 at 4:20pm

AP Chemistry
Which of the following sets of quantum numbers are allowed for an electron in a hydrogen atom? a)n=3, l=0, ml=0 b)n=4,l=1,ml=-1 c)n=2,l=1,ml=-2
Sunday, October 19, 2014 at 3:56pm

chemistry
When 2016 J of heat energy is added to 49.5 g of ethanol, C2H6O, the temperature increases by 16.6 °C. Calculate the molar heat capacity of C2H6O. 49.5g = 2.98mols C=q/n*temperature change in Celsius 2016/2.98*16.6
Sunday, October 19, 2014 at 3:43pm

Chemistry
when 2g of NaOH were dissolved in 149 g of H2o in a calorimeter at 24 degrees C the temperature of the solution went up to 29 degrees C. If the calorimeter constant was 11 cal/C find delta H for the solution of one mole of NaOH in H2O
Sunday, October 19, 2014 at 3:29pm

Chemistry
how many grams of NH3 can be produced from 4.35moles of N2 and excess H2
Sunday, October 19, 2014 at 2:58pm

Chemistry
What is another name for mole in Chemistry
Sunday, October 19, 2014 at 2:56pm

Chemistry
What is the numerical value of one mole?
Sunday, October 19, 2014 at 2:26pm

Chemistry
Why is the mole considered an important quality in Chemistry? What does it allow us to do?
Sunday, October 19, 2014 at 2:17pm

chemistry
s shell never forms pi bonds ,right?
Sunday, October 19, 2014 at 1:45pm

Chemistry
2NaN(3) > 2 Na +3N(2) What mass of sodium azide must be reacted to inflate and air bag to 70.0 L at STP?
Sunday, October 19, 2014 at 1:43pm

chemistry
a fur coat has C-14 activity 1/16 that of living tissue. How old is fur coat?
Sunday, October 19, 2014 at 12:06pm

chemistry
What is the pH of a solution of a monoprotic acid with a pKa of 6.6 if it is 39.3 % ionized in solution? Just provide the numerical answer, do not prefix with pH. Give your answer to two decimal places. Remember the definition of Ka
Sunday, October 19, 2014 at 12:02pm

chemistry
How many milliliters of a 0.200 M HI solution are needed to reduce 21.5 mL of a 0.365 M KMnO4 solution according to the following equation: 10HI+2KMnO4+3H2SO4 ---> 5I2+ 2MnSO4 +K2SO4+ 8H2O
Saturday, October 18, 2014 at 10:41pm

Chemistry
Weight of empty crucible and cover = 23.104 g Weight of crucible, cover, MgO and Mg3N2 = 24.199 g Weight of crucible, cover, MgOand addition of H2O and heat = 24.290 Calculate the number of moles of Mg3N2.
Saturday, October 18, 2014 at 8:28pm

Chemistry
Is there a reaction between Sodium Acetate and Copper (II) Nitrate. If so, what is the balanced equation for it? Also, what type of reaction is it does it form a precipitate?
Saturday, October 18, 2014 at 8:21pm

Chemistry HELP
In a constant-pressure calorimeter, 50.0 mL of 0.300 M Ba(OH)2 was added to 50.0 mL of 0.600 M HCl. The reaction caused the temperature of the solution to rise from 21.73 °C to 25.82 °C. If the solution has the same density and specific heat as water, what is ΔH ...
Saturday, October 18, 2014 at 8:04pm

college chemistry
When a 5.00-g sample of KCN is dissolved in water in a calorimeter that has a total heat capacity of 2.642 kJ·K–1, the temperature decreases by 0.340 K. Calculate the molar heat of solution of KCN.
Saturday, October 18, 2014 at 7:25pm

CHEMISTRY!!!!! HELP!!
I'm looking for a chemistry and applied chemistry textbook that had been published between 2011-2014. Please help because I couldn't find one on google.
Saturday, October 18, 2014 at 6:37pm

chemistry
which of the following is consistent with the line spectrum of the hydrogen atom? one of the choices is the nucleus is udnergoing gamma decay. but this si not one of the answers. Im just wondering what kind of decay happens?
Saturday, October 18, 2014 at 4:24pm

chemistry
You need 715 mL of a 45% alcohol solution. On hand, you have a 55% alcohol mixture. How much of the 55% alcohol mixture and pure water will you need to obtain the desired solution?
Saturday, October 18, 2014 at 3:06pm

Chemistry Check
Determine the missing values of deltaH in the diagram shown below ^ | ^ N2O3(g) + 1/2 O2(g) (Enthalpy)| | ^ | | deltaH= +16.02 | | | | | | 2 NO2(g) | | | ^ | |deltaH=? | | | | | | deltaH=?| | | | | | | | N2(g)+202(g) | Answer: Delta H for the right= 66.36 Delta H for the left...
Saturday, October 18, 2014 at 2:21pm

chemistry
Situation: You have 100ml of isotopically labelled water 3H2o. That is, the water is made with the radioactive isotope of hydrogen, tritium, 3H. Compounds that contain radioactive isotopes are called "hot." You pour this 100 mL of "hot" water into the ocean...
Saturday, October 18, 2014 at 1:23pm

Chemistry
What is the maximum velocity (in m/s) acquired by an alpha particle when accelerated between two plates with a potential difference of 580.0 volts? Note: An alpha particle is essentially the nucleus of a helium atom - 2 protons and 2 neutrons.
Saturday, October 18, 2014 at 11:32am

Chemistry
7. The specific heat of wood is 2.03 J/g∙°C. How much heat is needed to convert 550. g of wood at -15.0°C to 10.0°C?
Saturday, October 18, 2014 at 10:50am

Chemistry
1)What could have caused the impurity in the sodium hydroxide solution? 2)Why was it necessary to dilute the hydrochloric acid before carrying out the titration? This was a question from a titration practical in which we had to dilute HCL then use that along with 25cm3 of NaOH...
Saturday, October 18, 2014 at 5:38am

chemistry
A dilute solution of sulfiric acid is added to 15g of copper and iron mixture. a) the volume of h2 envolved at standard conditions is 4.48L what is the mass of each of the metals constituting the mixture ? Vm=24l.mol.
Saturday, October 18, 2014 at 5:33am

chemistry
Table salt, NaCl(s), and sugar, C12H22O11(s), are accidentally mixed. A 4.00-g sample is burned, and 3.30 g of CO2(g) is produced. What was the mass percentage of the table salt in the mixture?
Friday, October 17, 2014 at 7:56pm

Chemistry
Ho w
much 
water
 would 
you 
need 
to
 add
 to

500
mL
 of 
a 
0.3
M
 calcium
 nitrate 
solution
 to 
make the
 solution
 0.1
M? A.
...
Friday, October 17, 2014 at 4:08pm

Chemistry 101
Based on the masses of CaCl2 and Na3PO4 you determine from the periodic table,what mass combining ratio would you predict?
Friday, October 17, 2014 at 3:46pm

chemistry
what volume of 0.150M Li2Sr solution is required to completely react with 130ml of 0.150M Co(NO3)2
Friday, October 17, 2014 at 1:49am

chemistry
Propane (C3H8) which is used as fuel in BBQ tanks often contains some butane(C4H10). A sample of a fuel mixture known to contain both propane and butane occupies a certain volume at a total pressure of 30 mmHg. The sample is then burned completely to produce CO2 and H2O. The ...
Friday, October 17, 2014 at 1:14am

chemistry
A co-op student designed an experiment to collect hydrogen gas by reacting iron with a hydrochloric acid (HCl) solution. The student’s co-op supervisor suggested that aluminum can also be included to generate hydrogen gas: Fe + 2 HCl → 2 FeCl2 + H2 2 Al + 6 HCl &#...
Friday, October 17, 2014 at 1:12am

Chemistry
If 4.7M SrLi2 solution is diluted to 45L, what is the molarity of the diluted solution?
Friday, October 17, 2014 at 12:45am

CHEMISTRY
Find the number of SiO2 formula units in m = 1.90g of quartz.
Thursday, October 16, 2014 at 10:35pm

chemistry
a sample of freon-12 occupies 25.5 litters at 28 celsius find its volume at 15 degree celcius when the pressure is kept constant
Thursday, October 16, 2014 at 10:29pm

chemistry
How would you prepare 385 ml of a 0.856 m NaOH solution starting with a 4.93 m stock solution
Thursday, October 16, 2014 at 10:24pm

chemistry
How many grams of HCl are formed from reaction of 3.58g of H2 with 8.90g of Cl2?
Thursday, October 16, 2014 at 10:04pm

chemistry
how many sig figs are in 85,100?
Thursday, October 16, 2014 at 8:11pm

Chemistry
A 2.764 g sample containing only iron and aluminum metal was treated with acid to form Al(+3) and Fe(+2). The sample was then titrated with a potassium dichromate solution (only the Fe(II) will react with the dichromate). The sample was found to be equivalent to 14.36 mL of 0....
Thursday, October 16, 2014 at 7:35pm

Chemistry
when 2 moles of potassium chlorate crystals decompose to potassium chloride crystals and oxygen gas at a constant pressure and temperature, 78.0 kj of heat is given off. write a thermodynamic equation for this reaction.I don't know how to set up the equation i know that ...
Thursday, October 16, 2014 at 7:11pm

chemistry
what is the volume of 3.85x10^24 molecules of AMmmonium Bromide? please explain I'm confused
Thursday, October 16, 2014 at 5:01pm

Chemistry
1/2 H2(g) + 1/2 I2(g) -> HI(g) △H= +28kJ The activation energy for the formation of HI is 167kJ. The activation energy for the decomposition of HI is A. 28kJ B.139kJ C.167kJ D.195kJ I know it is an endothermic reaction.
Thursday, October 16, 2014 at 3:58pm

Chemistry
Please help! I don't understand these questions at all. :( Fe2O3(s) + 2Al(s) -> Al2O3(s) + 2Fe(l) If 0.50 mol of Fe is produced in 10 secs, what is the rate of consumption of Fe2O3 in mol/s? A. 5.0 x 10^-2 mol/s B. 2.5 x 10^-2 mol/s C. 1.0 x 10^-1mol/s D. 5.0 mol/s ...
Thursday, October 16, 2014 at 3:38pm

Chemistry
Increasing the surface area will increase the reaction rate in: 1. N2(g) + O2(g) -> 2NO(g) 2. 2Mg(s) + O2(g) -> 2MgO(s) 3. CaCO3(s) + 2H+(aq) -> Ca2+(aq) + H2O(l) + CO2(g) MY WORK: I think it is 2 & possibly 3. 1 is a homogeneous reaction but is 3 a heterogeneous ...
Thursday, October 16, 2014 at 3:16pm

chemistry
Calculate the theoretical yield of alum if 0.200g of Aluminum was reacted with excess KOH and H2SO4? I don't even know how to start it. Please help. Also I wanted to say thank you for the help I've gotten from this website it has helped me a lot. I feel like I'm ...
Thursday, October 16, 2014 at 12:48pm

Chemistry
If 6.0 g of Oxygen (O2) reacts with 12.0 g of hydrogen (H2) to give 5.0 g of dihydrogen monoxide. What's the % yield?
Thursday, October 16, 2014 at 12:11pm

Chemistry
A student determines the iron (II) content of a solution by first precipitating it as iron (II) hydroxide, and then decomposing the hydroxide to iron (II) oxide by heating. How many grams of iron (II) oxide should the student obtain if her solution contains 46.0 mL of 0.426 M ...
Thursday, October 16, 2014 at 11:54am

Chemistry
Calculate the number of milliliters of 0.782 M KOH required to precipitate all of the Mn2+ ions in 112 mL of 0.461 M Mn(NO3)2 solution as Mn(OH)2.
Thursday, October 16, 2014 at 11:40am

chemistry
Twenty grams of aluminum metal at 83.2 C were mixed with 49.3 g of water at 19.7 C. Assuming no heat loss, what was the final temperature of the Aluminum water metal? specific heat for Al= 0.215 specific heat for H2O=1.00
Wednesday, October 15, 2014 at 11:58pm

chemistry
A 1.07g sample of sulfur was burned in a bomb calorimeter whose calorimeter constant is 2.03 k cal/C. If the resulting temperature change was 1.17 C, what is the molar heat of combustion for sulfur?
Wednesday, October 15, 2014 at 11:56pm

Chemistry
A compound containing boron and hydrogen has been synthesized. You perform two experiments to determine the molecular formula of the compound. A 0.492 g sample of the compound is burned in pure oxygen to produce B2O3 and 0.540 g of water. In the second experiment, when a 63.1 ...
Wednesday, October 15, 2014 at 11:07pm

chemistry
Why is the crude product isoamyl bromide washed with water from isoamyl alcohol? (What is removed by this wash?)
Wednesday, October 15, 2014 at 10:26pm

chemistry
1) Aqueous solutions of potassium sulfate and ammonium nitrate are mixed together. Which statement is correct? A) Both KNO3 and NH4SO4 precipitate from solution B) A gas is released C) NH4SO4 will precipitate from solution D) KNO3 will precipitate from solution E) No reaction ...
Wednesday, October 15, 2014 at 9:59pm

Chemistry
How many numbers of oxygen molecules are present in 3 liters of CO2 at STP?
Wednesday, October 15, 2014 at 9:48pm

Chemistry
Does anyone know a website with practice problems (and answers) regarding quantitative chemistry? I haven't been able to find anything on Google.
Wednesday, October 15, 2014 at 9:36pm

Chemistry
Calculate the mass of water having the same number of hydrogen atoms as are present in 32 gm of methane.
Wednesday, October 15, 2014 at 9:32pm

CHEMISTRY
Balance the following equation. (for a balanced eq. aA + bB → cC + dD, enter your answer as the integer abcd) CrO42−(aq) + H2O(l) + HSnO2− → CrO2−(aq) + OH−(aq) + HSnO3−(aq)
Wednesday, October 15, 2014 at 9:01pm

Chemistry
What volume of CO2 gas is produced when 20 gm of 20% pure CaCO3 is completely heated?
Wednesday, October 15, 2014 at 8:57pm

Chemistry
a 191 g piece of copper is heated to 100 C in a boiling water bath and then dropped into a beaker containing 755 g of water (density =1.00 g/cm3) at 4.0 C. What is the final temperature of the copper and water after thermal equilibrium is reached? (Scu=0.385 J/g•K)
Wednesday, October 15, 2014 at 8:22pm

Pages: <<Prev | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | Next>>

Post a New Question | Current Questions

Homework Help: Science

Search
Members