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July 28, 2014

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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chemistry
calculate the number of molecules found in 4.50 g of water
Sunday, March 2, 2014 at 5:53pm

Chemistry
3) A student mistakenly uses the cuvette containing the most dilute standard solution, rather than the cuvette containing deionized water, as the blank solution. I don't understand why there would be lower concentration of Cr(VI) ion...
Sunday, March 2, 2014 at 5:20pm

Chemistry: Check my answers please!
How would each of the following affect the Cr(VI) concentration determined in this experiment? Justify the answers with an explanation. In the experiment, absorption spectroscopy was used to obtain the concentration of Cr(VI) ions. 1) A student adds more standard solution than...
Sunday, March 2, 2014 at 4:38pm

Chemistry
An atmospheric scientist interested in how NO is converted into NO2 in urban atmospheres carries out two experiments to measure the rate of this reaction. The data are tabulated below. A: [NO]0 = 9.63 × 10-3 M, [O2]0 = 4.1 × 10-4 M t(s) 0/3.0/6.0/9.0/12.0 [O2] 4.1/...
Sunday, March 2, 2014 at 2:51pm

chemistry
How many molecules are in 0.400 moles of N2 O5?
Sunday, March 2, 2014 at 2:29pm

Chemistry
How would applying an external pressure on the following equilibrium affects the distribution of iodide between the polar (aqueous) and non polar (varsol)
Sunday, March 2, 2014 at 12:29pm

Chemistry: HELP! PLEASE
a) Addition of Na2S2O3 to I2+I-->I3 in an aqueous layer will turn the solution clear and colourless. Write an equation explaining this observed colour. b) Addition of Na2S2O3 to I2+I-->I3 in an varsol layer will turn the solution pink. Write and equation explaining this ...
Sunday, March 2, 2014 at 11:28am

Chemistry
How would one be able to identify the lambda max of Cr(III) at a concentration less than 70ppm from a graph? I couldn't post the graph, but I don't understand how one would be able to do this? The graph had the Chromium Absorbance Spectra of 70ppm for Cr(VI) and Cr(III...
Sunday, March 2, 2014 at 1:02am

Chemistry
How would one be able to identify the lambda max of Cr(III) at a concentration less than 70ppm from a graph? I couldn't post the graph, but I don't understand how one would be able to do this? The graph had the Chromium Absorbance Spectra of 70ppm for Cr(VI) and Cr(III...
Sunday, March 2, 2014 at 12:57am

Chemistry
How would each of the following affect the Cr(VI) concentration determined in this experiment? Justify the answers with an explanation. In the experiment, absorption spectroscopy was used to obtain the concentration of Cr(VI) ions. 1) A student adds more standard solution than...
Sunday, March 2, 2014 at 12:47am

chemistry
1) List a series of tests that would determine the order of activity (least active to most active) for Zn, Mn, and Ag. 2) What would be the reaction for the addition of excess OH- ions to Mg(NO3)2 and Cu(NO3)2? This is a complex ion forming reaction. Would the complete ionic ...
Sunday, March 2, 2014 at 12:21am

chemistry
write the net ionic equation for the following molecular equation. 2Crl(aq)+3NaCO3(aq) ---> Cr2(CO3)3(s) + 6NaI(aq)
Saturday, March 1, 2014 at 10:20pm

chemistry
what is the net ionic equation for the following molecular equation. HNO3 is strong electrolyte and CH3COOH is weak electrolyte. NaCH3COO(aq)+HNO3(aq)----->NaNO3(aq)+​CHOOH(aq) the same question says use H+ for the hydronium ion, CH3OOH for acetic acid and CH3COO for ...
Saturday, March 1, 2014 at 9:00pm

Chemistry
net ionic equation for the following molecular equation. HNO3 is strong electrolyte and CH3COOH is weak electrolyte. NaCH3COO(aq)+HNO3(aq)----->NaNO3(aq)+​CHOOH(aq
Saturday, March 1, 2014 at 8:08pm

Chemistry
net ionic equation for the following molecular equation. HNO3 is strong electrolyte and CH3COOH is weak electrolyte. NaCH3COO(aq)+HNO3(aq)----->NaNO3(aq)+​CHOOH(aq
Saturday, March 1, 2014 at 8:03pm

organic chemistry
i have a 'ethanol benzene' and i have to add H3O+ (elimination). what will my product be? will the H3O attack the OH on the chain or will it attack the ring?
Saturday, March 1, 2014 at 7:43pm

chemistry
when magnesium chlorate under goes decompostion, oxgen gas is realsed in the following reaction: 2KClO3→ 2KCl + 3O2 repeat 2KClO3→ 2KCl + 3O2 when 3.50 grams of potassuim chlorate is decomposed at STP, how many litters of oxgen will be produced? chemistry - Da
Saturday, March 1, 2014 at 6:56pm

chemistry
A sample of gas is compressed from 13.57 L to 3.93 L using a constant external pressure of 2.91 atm. At the same time, 1,759 J of heat flows into the surroundings. What is the internal energy change for the gas?
Saturday, March 1, 2014 at 6:29pm

chemistry
A 0.016076-mol sample of an organic compound was burned in oxygen in a bomb calorimeter. The temperature of the calorimeter increased from 23.7oC to 24.5oC. If the heat capacity of the calorimeter is 4.98 kJ (oC)-1, then what is the constant volume heat of combustion of this ...
Saturday, March 1, 2014 at 6:29pm

chemistry
The enthalpy change for the reaction below at 25oC is -2,051 kJ (per mole of C10H22). What is the internal energy change for the reaction at 25oC? 10 CO(g) + 21 H2(g) --> C10H22(l) + 10 H2O(l) Enter your answer in kJ (per mole of C10H22), rounded to the nearest kilojoule.
Saturday, March 1, 2014 at 6:28pm

chemistry
The standard enthalpy of combustion of C2H6O(l) is -1,367 kJ mol-1 at 298 K. What is the standard enthalpy of formation of C2H6O(l) at 298 K? Give your answer in kJ mol-1, rounded to the nearest kilojoule. Do not include units as part of your answer. Note: The standard ...
Saturday, March 1, 2014 at 6:27pm

chemistry
Given the following thermochemical equations, NO(g) + (1/2) Cl2(g) --> NOCl(g) -37.78 kJ (per mol NOCl) NO(g) + (1/2) O2(g) --> NO2(g) -56.53 kJ (per mol NO2) 2 NO2(g) --> N2O4(g) -58.03 kJ (per mol N2O4) what is the standard enthalpy change for the reaction below? ...
Saturday, March 1, 2014 at 6:26pm

chemistry
When a 6.79-g mixture of methane, CH4, and ethane, C2H6, is burned in oxygen at constant pressure, 369 kJ of heat is liberated. What is the percentage by mass of CH4 in the mixture? The standard enthalpies of combustion for CH4 and C2H6 are -890.3 kJ mol-1 and -1569.7 kJ mol-1...
Saturday, March 1, 2014 at 6:26pm

chemistry
What is w when 1.27 kg of H2O(l), initially at 25.0oC, is converted into water vapour at 133oC against a constant external pressure of 1.00 atm? Assume that the vapour behaves ideally and that the density of liquid water is 1.00 g/mL. (Remember to include a "+" or &...
Saturday, March 1, 2014 at 6:25pm

Chemistry
At STP how many L of N2 are produced if 1 mol of NaN3 and .200 moles of KNO3 are in the air bag?
Saturday, March 1, 2014 at 6:03pm

chemistry
magnesium chlorate under goes decompostion, oxgen gas is realsed in the following reaction: 2KClO3 → 2KCl + 3O2 when 3.50 grams of potassuim chlorate is decomposed at STP, how many litters of oxgen will be produced?
Saturday, March 1, 2014 at 5:34pm

chemistry
A buffer solution is prepared by mixing 99.0 mL of 0.450 M HF and 55.0 mL of 1.15 M NaF. Determine the pH of the solution after the addition of 0.01 moles NaOH (assume there is no change in volume when the NaOH is added).
Saturday, March 1, 2014 at 4:47pm

chemistry
What is the molality of a solution made by adding 0.130 g of zinc sulfite to 151 ml water?
Saturday, March 1, 2014 at 4:41pm

Chemistry
Based on your observation, how would you precipitate BaCrO4 (s) from a solution of Ba(NO3)2 and K2Cr2O7 2-? Need to show chemical equation and explain.
Saturday, March 1, 2014 at 3:54pm

chemistry
Hello, a few questions: Thanks so much! 1. The heat capacities of titanium and water are 0.522 J g-1 K-1 and 4.184 J g-1 K-1, respectively. What is the final temperature of the titanium-water mixture if a 175.0-g sample of titanium, initially at 90.0oC, is added to 50.0 g of ...
Saturday, March 1, 2014 at 3:51pm

chemistry
when magnesium chlorate under goes decompostion, oxgen gas is realsed in the following reaction: 2KClO3→ 2KCl + 3O2 when 3.50 grams of potassuim chlorate is decomposed at STP, how many litters of oxgen will be produced?
Saturday, March 1, 2014 at 3:05pm

chemistry
at a certain temperature 800 mole of so3 is placed in a 4.00-l container. 2SO3(g)<-->2SO2(g)+O2(g) at equilibrium, 0.120 mol of o2 is present. calculate kc
Saturday, March 1, 2014 at 3:02pm

chemistry
how to calculate the amount of heat in calories absorbed when 50.0 g of water at 20 degrees C spreads over your skin and warms the body temperature, 37 degrees C
Saturday, March 1, 2014 at 1:58pm

Chemistry
The value of KC for the interconversion of butane and isobutane is 2.5 at 25°C. If you place 0.067 mol of butane in a 0.250-L flask at 25°C and allow equilibrium to be established, what will be the concentrations of the two forms of butane? A)[butane] B)[isobutane]
Saturday, March 1, 2014 at 12:46pm

Chemistry
How has crude oil changes the country (positive and negative points)
Saturday, March 1, 2014 at 5:00am

chemistry
what is the disadvantage of nh4oh
Friday, February 28, 2014 at 8:35pm

Chemistry
Carbonates react with acids to form a salt, water and carbon dioxide gas. When 22.1 g of calcium carbonate are reacted with sufficient hydrochloric acid, how many grams of calcium chloride will be produced?
Friday, February 28, 2014 at 7:52pm

Chemistry
A cell was constructed with two lead electrodes. The electrolyte compartment is 1 M Pb(NO3)2 (aq). In the other compartment, NaI has been added to a Pb(NO3)2 solution until a yellow precipitate forms and the concentration of I- ions is .5 M. The potential of the cell is .155 V...
Friday, February 28, 2014 at 3:00pm

Chemistry
The values on the label of a bottle of nitric acid are specific gravity 1.42 and assay 60%. Use these values to determine the molarity of the solution. Show your work.
Friday, February 28, 2014 at 1:54pm

chemistry
use the Henderson-Hasselbalch equation to calculate the pH of a buffer solution prepared by mixing equal volumes of 0.20 M NaHCO3 and 0.10M Na2CO3.(Ka=5.6x10^-11). how would you prepare NaHCO3-Na2CO3 buffer solution that has the pH of 10.40.
Friday, February 28, 2014 at 1:40pm

Analytical Chemistry
Match the following terms about analytical precipitations to their definitions: A.) Coprecipitation B.) Adsorption C.) Absorption D.) Gathering E.) Masking F.) Digestion G.) Peptization 1.) Inclusion or occlusion of impurities within a crystal. 2.) Binding of impurities to the...
Friday, February 28, 2014 at 1:20pm

chemistry
Given an approximate wavenumber of 2000cm-1 for CN, calculate the approximate force constant for a single bond. i used the formula v= (1/2(pi)c) * sqrt(k/u) where pi is 3.14, c is the speed of light, k is the force constant and u=mu, which is the reduced mass. i got a value of...
Friday, February 28, 2014 at 12:41pm

Chemistry
Urea (NH2)2CO is prepared by reacting ammonia with carbon dioxide. The byproduct is water. 637.2g of ammonia are reacted with 787.3 g of carbon dioxide. a. (15 points) Which of the two reactants is a limiting reactant? Show your calculations (including the correctly balanced ...
Friday, February 28, 2014 at 5:21am

Chemistry
What is true about the element francium (Fr, atomic number 87)? Choose all that apply. A) It has seven valence electrons. B) It is likely to form ionic bonds. C) It is in Period 7. D) It is nonmetal. E) It is a metal. I think it is B, C, and E?
Friday, February 28, 2014 at 1:30am

Chemistry
Consider the following equation: TiCl4(g) + 2Mg(l) → Ti(s) + 2MgCl2(l) 3.54×107g of TiCl4(g) are reacted completely. If 7.91×106g of Ti(s) is actually obtained, calculate the % yield.
Thursday, February 27, 2014 at 9:28pm

Chemistry
Urea (NH2)2CO is prepared by reacting ammonia with carbon dioxide. The byproduct is water. 637.2g of ammonia are reacted with 787.3 g of carbon dioxide. a. Which of the two reactants is a limiting reactant? Show your calculations (including the correctly balanced chemical ...
Thursday, February 27, 2014 at 9:17pm

Chemistry
If 25g of lead phosphate reacts with an excess of sodium nitrate, how many dreams of sodium phosphate is produced?
Thursday, February 27, 2014 at 9:06pm

Chemistry (Thermodynamics)
Write a balanced equation for the complete combustion of 1 mole of ethyne gas (C2H2) ?
Thursday, February 27, 2014 at 9:03pm

Chemistry
If say 70 mL of water is heated vs 100 mL of water, would the temperature be different or does the amount of the substance not make a difference on the temperature Thanks!
Thursday, February 27, 2014 at 8:59pm

Chemistry
5.3g of magnesium reacts with excess HCI. How many liters of hydrogen gas will be produced?
Thursday, February 27, 2014 at 8:13pm

Chemistry
Same with these: How do you do them? 1.)What is the mass at 20 degrees Celsius of 5 liters of air? 2.)What is the volume in liters of a kilogram of ice at 0 degrees Celsius? 3.)What is the mass of a bar of aluminum measuring 1.0cm by 1.0cm by 10.0cm?
Thursday, February 27, 2014 at 6:34pm

Chemistry
Use standard enthalpies of formation to determine ΔHorxnfor: 3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g) -133.5 = Delta H Find the change in internal energy for this reactioion.. ???? In KJ
Thursday, February 27, 2014 at 6:27pm

Chemistry
Same with these: How do you do them? 1.)What is the mass at 20 degrees Celsius of 5 liters of air? 2.)What is the volume in liters of a kilogram of ice at 0 degrees Celsius? 3.)What is the mass of a bar of aluminum measuring 1.0cm by 1.0cm by 10.0cm?
Thursday, February 27, 2014 at 6:12pm

Chemistry
The speed limit on a certain highway is 72km/h. What is the speed in cm/s? Could you go through each step on how to get the answer? Lots of the questions are like this one, but I don't know how to do them.
Thursday, February 27, 2014 at 6:04pm

Chemistry
Predict the standard cell potential and calculate the standard reaction Gibbs free energy for galvanic cells having the following cell reactions: a.)3Zn + 2Bi3+ = 3Zn2+ + 2Bi b.)2H2 + O2 = 2H20 in acidic solution c.)2H2 + O2 = 2H20 in basic solution d.)3Au+ = 2Au + Au3+ I ...
Thursday, February 27, 2014 at 5:52pm

Chemistry
Calculate the standard reaction Gibbs free energy for the following cell reactions: a.)3Cr3+(aq) + Bi(s)= 3Cr2+(aq) + Bi3+(aq) with Ecell=-.61V b.)Mg(s) + 2H20(l)=Mg2+(aq)+H2(g)+2OH-(aq) with Ecell=2.36 V I know the formula. I just need help figuring out n (change in number of...
Thursday, February 27, 2014 at 4:34pm

Chemistry
If 507 g FeCL2 were used up in the reaction FeCL2 + 2NaOH > Fe(OH)@(s) + 2NaCL, how many grams of Fe(OH)2 would be formed?
Thursday, February 27, 2014 at 1:13pm

chemistry
what volume would 4.3 moles of hydrogen gas occupy at 45 degrees and 3.22 atm?
Thursday, February 27, 2014 at 10:19am

chemistry
A set of bookshelves rests on a hard floor surface on four legs, each having a cross-sectional dimension of 3.9 6.5 cm in contact with the floor. The total mass of the shelves plus the books stacked on them is 260. kg. Calculate the pressure in pascals exerted by the shelf ...
Thursday, February 27, 2014 at 12:05am

chemistry
a solution of 2.5 M weak acid is .52% ionized. what is the Ka value of this acid? ive been stuck on this one for a long time and cant figure out where to even start...if someone could walk me through this itd be great! thanks
Wednesday, February 26, 2014 at 8:58pm

Chemistry
A sample of oxygen gas at 295 kPa takes up 456 L of space at standard temperature (the “T” in STP). What is the new volume when the pressure is lowered to standard pressure (the “P” in STP)?
Wednesday, February 26, 2014 at 8:02pm

Chemistry
Calculate the volume of .100M NaOH that must be added to reach ph of 3 in the titration of 25.00 mL of .100M HCl
Wednesday, February 26, 2014 at 7:44pm

Chemistry help!
A sample of gas at a temperature of 37.0°C has a pressure of 725 torr and occupies a volume of 3.44 L. a. Use Boyle’s law to calculate the new pressure if the temperature is held constant and the volume is increased to 6.54 L. torr b. Use Gay-Lussac’s law to ...
Wednesday, February 26, 2014 at 6:46pm

Chemistry
a. How many moles of N2 are present in a 1.00 qt flask that has a pressure of 425 torr at a temperature of 35°C? What is the mass in this na2? It would be much simpler to change quart to liters first, then torr to kpa PV=nRT n= PV/RT Temps in Kelvins, V in liters, P in ...
Wednesday, February 26, 2014 at 5:57pm

Chemistry
1. Consider a 1.00g unknown sample that contains 62.0% sodium carbonate and 38.0% sodium bicarbonate, NaHCO3, by mass. When this sample is dissolved in water, how many mL of 0.200M HCl will be required to convert all of the carbonate to bicarbonate? How many mL will be ...
Wednesday, February 26, 2014 at 5:03pm

Chemistry
a. How many moles of N2 are present in a 1.00 qt flask that has a pressure of 425 torr at a temperature of 35°C? What is the mass in this na2? It would be much simpler to change quart to liters first, then torr to kpa PV=nRT n= PV/RT Temps in Kelvins, V in liters, P in kpa...
Wednesday, February 26, 2014 at 4:39pm

Chemistry
150.0 mL flask contains 740. g of N2 at 0°C. What is the pressure in atm. What is the pressure in torr? What is the pressure in psi? I know you have to do: n = grams/molar mass Then PV = nRT R in 0.08206 L.atm/mol.K gives P in atm atm x 760 = p in torr 1 atm = 14.7 psi
Wednesday, February 26, 2014 at 4:37pm

Chemistry
A mixture of gases contains 0.65 mol of N2, 0.70 mol of O2, and 0.90 mol of He. What is the partial pressure of each gas (in atm and in torr) in a 25.0 L cylinder at 340 K? What is total pressure? I know you: Use mols each gas in PV = nRT and solve for p. Then Ptotal = pN2 + ...
Wednesday, February 26, 2014 at 4:36pm

Chemistry
At a temperature of 57oC, a gas inside a 5.30 L metal canister has a pressure of 4000 torr. If the temperature is decreased to 13oC (at constant volume), what is the new pressure of the gas? I know you use the formula (P1/T1) = (P2/T2)
Wednesday, February 26, 2014 at 4:35pm

Chemistry
At a pressure of 2.4 atm a balloon has a volume of 9.8 L. If the pressure is decreased to 0.96 atm (at constant temperature), what is the new volume of the balloon. I know you use the formula P1V1 = P2V2
Wednesday, February 26, 2014 at 4:34pm

Chemistry
A 630. mL flask contains O2 at a pressure of 0.75 atm and a temperature of 20°C. What mass of O2 is present? I know you Use PV = nRT and solve for n = number of mols gas. Then n = grams/molar mass and solve for grams. But I get the wrong answer
Wednesday, February 26, 2014 at 4:33pm

Please help with Chemistry?????
5.00 mL of 2.00x10^-3M Fe(NO3)3 is mixed with 4.03 mL of 2.00x10^-3M NaSCN and 1.08 mL of 0.1M HNO3, for a total volume of 10.11 mL. a) What is the initial concentration of the Fe(NO3)3 in the mixed solution? b) What is the initial concentration of the NaSCN in the mixed ...
Wednesday, February 26, 2014 at 3:18pm

Please help with Chemistry?????
A standard solution with a FeSCN2+ concentration of 1.55x10^-4M has a percent transmittance (%T) of 18.8%. Another solution of unknown FeSCN2+ concentration has a percent transmittance of 44.8%. A) Calculate the absorbance (A) of each solution. B) Using the absorbances ...
Wednesday, February 26, 2014 at 3:17pm

Chemistry
a. How many moles of N2 are present in a 1.00 qt flask that has a pressure of 425 torr at a temperature of 35°C? What is the mass in this na2?
Wednesday, February 26, 2014 at 3:09pm

Chemistry
A 150.0 mL flask contains 740. g of N2 at 0°C. What is the pressure in atm. What is the pressure in torr? What is the pressure in psi?
Wednesday, February 26, 2014 at 3:07pm

Chemistry
EOC Problem 6.046 A mixture of gases contains 0.65 mol of N2, 0.70 mol of O2, and 0.90 mol of He. What is the partial pressure of each gas (in atm and in torr) in a 25.0 L cylinder at 340 K? What is total pressure?
Wednesday, February 26, 2014 at 3:05pm

Chemistry
At a temperature of 57oC, a gas inside a 5.30 L metal canister has a pressure of 4000 torr. If the temperature is decreased to 13oC (at constant volume), what is the new pressure of the gas?
Wednesday, February 26, 2014 at 3:03pm

Chemistry
At a pressure of 2.4 atm a balloon has a volume of 9.8 L. If the pressure is decreased to 0.96 atm (at constant temperature), what is the new volume of the balloon?
Wednesday, February 26, 2014 at 3:02pm

Chemistry
A 630. mL flask contains O2 at a pressure of 0.75 atm and a temperature of 20°C. What mass of O2 is present?
Wednesday, February 26, 2014 at 3:01pm

Chemistry
A standard solution with a FeSCN2+ concentration of 1.55x10^-4M has a percent transmittance (%T) of 18.8%. Another solution of unknown FeSCN2+ concentration has a percent transmittance of 44.8%. A) Calculate the absorbance (A) of each solution. B) Using the absorbances ...
Wednesday, February 26, 2014 at 2:39pm

Chemistry
5.00 mL of 2.00x10^-3M Fe(NO3)3 is mixed with 4.03 mL of 2.00x10^-3M NaSCN and 1.08 mL of 0.1M HNO3, for a total volume of 10.11 mL. a) What is the initial concentration of the Fe(NO3)3 in the mixed solution? b) What is the initial concentration of the NaSCN in the moxed ...
Wednesday, February 26, 2014 at 2:36pm

Chemistry please help
In lab, I weighed out and found the molarity of 1.108g Na2C2O4 and 1.100g K3Fe(C2O4)3. I titrated an average of 0.0335L of the sodium oxalate solution with KMnO4(potassium permanganate). I then titrated an average of 0.0169L of K3Fe(C2O4)3 X 3H2O with potassium permanganate. I...
Wednesday, February 26, 2014 at 2:31pm

Lab/Chemistry
In lab, I weighed out and found the molarity of 1.108g Na2C2O4 and 1.100g K3Fe(C2O4)3. I titrated an average of 0.0335L of the sodium oxalate solution with KMnO4(potassium permanganate). I then titrated an average of 0.0169L of K3Fe(C2O4)3 X 3H2O with potassium permanganate. I...
Wednesday, February 26, 2014 at 1:10pm

Chemistry
The ionization constant Ka of an indicator HIn is 1.0x10^-6. The color of the nonionized form is red and that of the ionized form is yellow. What is the color of this indicator in a solution whose pH is 4.00? (The question mentions that you can use the ratio of HIn/In). I NEED...
Wednesday, February 26, 2014 at 11:17am

Chemistry
A solution has 140 grams of KOH dissovled in 5 L of water. What is the pH ?
Wednesday, February 26, 2014 at 11:10am

Chemistry
9. A solution has 48 grams of LiOH dissovled In 100 L of water. What is its [OH-]? 10. What is the pH of the solution in question 9?
Wednesday, February 26, 2014 at 11:09am

Chemistry
What is the pOH of the solution in the question I asked before this one?
Wednesday, February 26, 2014 at 11:07am

Chemistry
A solution has 0.45 mol of NaOH dissovled in 90 L of water. What is its [OH-]?
Wednesday, February 26, 2014 at 11:07am

Chemistry
A solution has 189 grams of HNO3 dissolved in 1000L of water. What is pH?
Wednesday, February 26, 2014 at 11:05am

Chemistry
How much water is needed to prepare 8M of NaOH solution with 1kg of NaOH pellets?
Wednesday, February 26, 2014 at 9:02am

chemistry
at an equilibrium mixture of PCl5, PCl3, and Cl2 has partial pressures of 217.0 Torr, 13.2 Torr and 13.2 Torr respectively. a quantity of Cl2 is injected into the mixture, and the total pressure jumps to 263.0 Torr (at the moment of mixing). the system then re-equilibrates. ...
Wednesday, February 26, 2014 at 5:14am

Chemistry
A molecular compound has the empirical formula CH2. When 100mg of the compound is dissolved in 1.00 g of benzene, the solution freezes 1.75 degrees celsius lower than pure benzene. The Kf for benzene is 4.90 C/m. What is the MM of the compound?
Wednesday, February 26, 2014 at 1:44am

chemistry
if a college student went into the lab and produced 45 grams of Na2CO3, what is percent yield of this trial?
Tuesday, February 25, 2014 at 11:29pm

chemistry
What is the molarity of a solution composed of 2.23 g of potassium iodide (KI) dissolved in enough water to make 0.181 L of solution? Answer in units of M
Tuesday, February 25, 2014 at 11:25pm

Chemistry
Calculate [OH−] for 1.90mL of 0.190M NaOH diluted to 1.50L .
Tuesday, February 25, 2014 at 9:45pm

Chemistry
One day at the fertilizer factory, your boss Mr. Haber comes to you with a problem. The process used by the factory to produce ammonia,the raw material for your fertilizer, is just not optimized. He would like to modify the conditions to achieve a better yield of ammonia in ...
Tuesday, February 25, 2014 at 9:24pm

Chemistry 1150
Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin plastic divider. When the divider is broken, the ammonium nitrate dissolves according to the following endothermic reaction: NH4NO3(s)→NH+4(aq)+NO...
Tuesday, February 25, 2014 at 9:14pm

Chemistry
When 10.00g of phosphorus is burned in O2(g) to form P4O10(s), enough heat is generated to raise the temperature of 2990g of water from 18.0 ∘C to 38.0 ∘C. Calculate the heat of formation of P4O10(s) under these conditions. -------------------------------------- ...
Tuesday, February 25, 2014 at 9:03pm

Chemistry
Calculate the total heat energy needed to convert 110g of ice at -10°C to steam at 110°C..?
Tuesday, February 25, 2014 at 9:02pm

chemistry
Is deltaH standard of TdeltaS standard more important in determining whether KHT will be soluble in water at a given temperature?
Tuesday, February 25, 2014 at 8:48pm

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