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Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
You vaporize a liquid substance at 90.0 °C and 795.0 mmHg. The volume of 0.548 g of vapor is 237 mL. What is the molecular weight (in amu) of the substance?

Chemistry
The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the net reaction H3AsO4 + 3I – + 2 H3O +→ H3AsO3 + I3– + H2O. The experimental rate law for this reaction is Rate = k [H3AsO4] [I–] [H3O+]. According to the rate law for the ...

chemistry
To determine the molecular weight of a liquid compound,1.56 grams of the compound is vaporized in a 0.555L container at 30ºC and the pressure is measured as 1.2 atm. What is the molecular weight of the compound?

chemistry
Question 16 options: A mixture of equal moles of He and Xe are in a plastic container at 25ºC and 874 mm pressure. If only He leaks from the container and the pressure decreases to 600 mm at 25º C, what is the mole fraction of (1) He and (2) Xe in the container after the leak?

Chemistry
KClO3 decomposes according to the reaction below. How many grams of KClO3 are needed to produce 826ml of O2 at standard temperature and pressure? 2KClO3 → 2KCl + 3O2

chemistry
Please help! N2H4 is decomposed in a closed container according to this reaction: N2H4 → N2 + 2H2 . If the temperature is constant and the initial pressure of N2H4 is 800mm, what will the pressure in millimeters be after the decomposition to N2 + 2H2?

Chemistry
Dinitrogen tetroxide decomposes to nitrogen dioxide: N2O4(g)→2NO2(g)ΔHorxn=55.3kJ At 298 K, a reaction vessel initially contains 0.100 atm of N2O4. When equilibrium is reached, 58% of the N2O4 has decomposed to NO2. What percentage of N2O4 decomposes at 350 K ? Assume that ...

Chemistry
Calculate the pressure of an ideal gas if you have 4.3 L and 2.2 miles at a temperature of 238 K

chemistry
ozonolysis with orthoxylene gives 3 different products explain

chemistry
ethyacetoacetate gives positive test with sodium bisulphate. explain

Chemistry
Determine the molarity of na2co3 solution by titrating it against M/10 H2so4 solution

Chemistry
A sample of Helium occupies 200 L at 30ºC under a pressure of 841 torr. What is the volume it occupies at standard temprature and pressure (STP)?

Chemistry
Of the following solids, which would have the highest melting point? Why? a. LiF b. LiCl c. LiBr d. LiI e. CsI My guess is LiF since it has F and F is the most electronegative element. However, I am not entirely sure.

chemistry
Nitrogen dioxide reacts with water droplets in the atmosphere to produce nitric acid and nitrous acid.

Chemistry
How would I balance Al2 + I2>ALI3

Chemistry
Calculate the amount of H2 produced from the reaction of 4.25 grams Zn and 25 ml of 3.0 M HCL.

Chemistry
What is the molarity of a solution made by dissolving 2.00g of potassium chloride (KCl) in enough water to make 150 ml of solution?

Chemistry
What is the equilibrium constant for the following reaction? 3A + 2B <---> 2C

Chemistry
When 52.7 g of octane (c8 h18) burns in oxygen, the percentage yield of carbon dioxide is 82.5%. what is the actual yield in grams?

chemistry
A swimming pool, 20.0 m ✕ 12.5 m, is filled with water to a depth of 3.81 m. If the initial temperature of the water is 18.9°C, how much heat must be added to the water to raise its temperature to 30.1°C? Assume that the density of water is 1.000 g/mL.

chemistry
Ethane(a minor constituent of natural gas) burns in oxygen to form carbon dioxide and water. How many moles of oxygen are needed to react with one moles of ethane?

Chemistry
is the flame coloration a test for the metal or for the acid radical?

Chemistry
Calculate the amount of H2 produced from the reaction of 4.25 grams Zn and 25 ml of 3.0 M HCL.

Chemistry
A chemist prepares a 45.0-g sample of carbon tetrachloride (CCl4). How many moles of this compound has she prepared? (Note: The atomic weight of carbon is 12.0 and of chlorine is 35.5.) how do i do this?

Chemistry
We are asked to prepare a 100 ml solution with the following 3 concentrations: 53.00 mg/ml sodium salicylate, 0.020 M FeCl3, and 0.050 M HCl. Then, we are going to take the absorbance at 520 nm. What is the best way to prepare the 100 ml solution ?

chemistry
How many molecules of lactose are there in one liter of buttermilk?

chemistry
3. A solution is made by dissolving 5.00 g of impure sodium hydroxide in water and making it up to 1.00dm3 of solution. 25.0 cm3 of this solution is neutralized by 30.0 cm3 of hydrochloric acid of concentration 0.102 mol/dm3. a) Calculate the number of mole of HCl. b) ...

chemistry
calculate the weight of nacl present in 250 g of 0.01m solution

chemistry
Given a 1.00 L solution that is 0.60 M HF and 1.00 M KF, calculate the pH after 0.080 mol NaOH is added, and calculate the pH after 0.24 mol HCl is added to the original solution.

chemistry
Why does CdS dissolve in HCL, when CuS and Bi2S3 will not?

Chemistry
Which of the following is true? A. In the human female, ovulation occurs in nine-month cycles. B. Egg cells develop in a structure called the uterus and are released at the rate of one a month. C. Spermatogenesis is the process of fertilization of the egg cell. D. The fluid in...

Chemistry
How many grams of CaCl2 are needed to prepare 25.0 mL of .500 M solution? and What volume of 12.00 M HCL is needed to prepare 150.0 mL of .500 M HCL?

Chemistry
Consider the following electrochemical cell: Al(s) | Al^3+(aq)(0.155 M) || H^(aq) (0.00233 M), MnO4^-(aq)(0.0377 M), Mn^2+(aq) (0.0168 M) | C (graphite) Write a balanced equation for the redox reaction taking place in this cell. i am having trouble with the cathode half ...

Chemistry
Arrange the following ions in terms of increasing atomic radius (arrange the increasing from left [lowest] to right [largest]): P3-, Cl-, K+, S2-

Chemistry
When 10.00 mL of 1.00 M HCl solution is mixed with 115 mL of 0.100 M NaOH solution in a constant-pressure calorimeter, the temperature rises from 22.45 °C to 23.25 °C. Calculate q for this reaction, assuming that the heat capacity of the calorimeter is the same as that of ...

Chemistry
Explain why only four ionization energies are listed for Beryllium in the table listing ionization energies of elements.

sammy
chemistry

Chemistry
Which statement about this reaction is FALSE? AgNO3 + NaCl -> AgCl + NaNO3 A. This is one kind of metathesis reaction, where molecules exchange atoms. B. This reaction produces a gas. C. This is a precipitation reaction. D. The equation is balanced

Chemistry
AgNO3 + NaCl -> AgCl + NaNO3 Which statement about this reaction is FALSE? A. This is one kind of metathesis reaction, where molecules exchange atoms. B. This reaction produces a gas. C. This is a precipitation reaction. D. The equation is balanced.

Chemistry
A 12.0 L sample of hydrogen gas has a pressure of 27.0 atm. What volume would this gas occupy at 3.70 atm? Assume ideal behavior.

Chemistry
Calculate the pH of 100.00 mL of an ammonia buffer (pKb = 4.76), prepared by placing 55.0 mL of concentrated NH4OH (i.e., NH3; 14.5 M) into a volumetric flask, adding 6.76 g of ammonium chloride, and diluting to the mark with DI water.

Chemistry
1. The atmosphere of earth is an example of what kind of solution? A. liquid-liquid B. gas-liquid C. gas-gas*** D. solid liquid 2. Which of the following will result in a greater amount of oxygen dissolving in water? A. Heat the water*** B. Decrease the oxygen gas pressure C. ...

Chemistry
What is the IUPAC name of CH2(OH)CH2(OH)

Chemistry
Write the overall cell reaction for a cell containing aluminum metal and Zinc(II)sulfate so would it be: Al (s) + ZnSO4 (aq) <---> Al3+ + ZnSO4 ?????? I tried to do it myself but I'm a bit confused... I'm confused about the charges because isn't ZnSO4 neutral since Zn is...

Chemistry
Could you show me where to start on solving this equation? The reaction in question will be carried out in a calorimeter. The volume of the chamber inside is 2.00 L. Experiment starts by evacuating the chamber to 0.00 kPa. Then oxygen gas is filled into the chamber till ...

chemistry
Calculate the free energy in a saturated solution of Ca(OH)2 if the Ksp =6.5x10-6 at 25 degrees Celsius. sorry to be a bother but I don't understand how to do this problem either.. can someone please explain this one to me as well?

chemistry
Answer the following questions based on the following electrochemical reaction: Al(s) + Cu 2+(aq) <====> Cu(s) + Al3+ (aq) Write the balanced chemical equation for this cell. I'm confused.. how would this be balanced?

Chemistry
Hydrogen sulfide gas is bubbled into a lead (II) acetate solution.

Chemistry
A buffer contains the weak acid HA abd its conjugated base A-. The weak acid has a Ka of 1.51 x10^-5 and the buffer has a pH of 4.25. Which statement is true about the relative concentrations of HA and A- in the buffer? A) [HA]>[A-] B) [HA]<[A-] C) [HA] = [A-]

Chemistry
Calculate ΔG° for each of the reactions below in kJ. (a) Sn(s) and Pb2+(aq) (b) Cr(s) and Cu2+(aq)

chemistry
Calculate the concentration of Ca+2 in a saturated solution of Ca(OH)2 if the Ksp = 6.5x10-6 at 25oC. can someone explain the steps to do this please? :)

Physics PLEASE HELP
Ernest Rutherford (the first New Zealander to be awarded the Nobel Prize in Chemistry) demonstrated that nuclei were very small and dense by scattering helium-4 nuclei (4He) from gold-197 nuclei (197Au). The energy of the incoming helium nucleus was 7.58 ✕ 10−13 J, and the...

chemistry
what's the difference between experimental estimate of sugar concentration and the true sugar concentration?

chemistry
zinc hyrdoxide + phosphoric acid --> zinc phosphate + water

Chemistry
lead (II) nitrate reacts with oxygen gas to produce diphosphoroous pentoxide

Chemistry
lead(II)nitrate reacts with oxygen gas to produce diphosphorous pentoxide

Chemistry
Could you show me where to start on solving this equation? The reaction in question will be carried out in a calorimeter. The volume of the chamber inside is 2.00 L. Experiment starts by evacuating the chamber to 0.00 kPa. Then oxygen gas is filled into the chamber till ...

Chemistry HELP!!!URGENT
Indicate which elements can be used as potential semiconductors, and which ones can be used as potential dopants used to make n-type and p-type semiconductors by placing them in the corresponding bin. F, Al, As, Ge, I. p-type semiconductors can consist of: a)highly purified ...

Chemistry
Could you show me where to start on solving this equation? The reaction in question will be carried out in a calorimeter. The volume of the chamber inside is 2.00 L. Experiment starts by evacuating the chamber to 0.00 kPa. Then oxygen gas is filled into the chamber till ...

chemistry
Why can't you form an acid salt from a monoprotic acid?

chemistry
How much heat in kJ is required to increase the temperature of an 87.0 g sample of water from 67oC to 136.6oC?

chemistry (I have a test tomorrow)
4 Ag + 2 H2S + O2 = 2 Ag2S + 2 H2O a) What mass if silver sulfide is formed from the reaction of 0.120g of silver? b) What mass of hydrogen sulfide is needed in the same process? So I understand a, and I found the answer to be 0.138g. For b the text book says the answer is 0....

chemistry
In the predicted electron configuration of Molybdenum (Mo), how many electrons are in the 4d subshell? 2. How many electrons are in the 4d subshell of the Molybdenum (III) ion?

Chemistry
What would be the effect on Ksp if an unsaturated solution of CaSO4 was titrated instead of a saturated solution of CaSO4. would ksp be higher, lower or the same? would ksp be higher due to the more ions available in the solution. so you would have to use more titrant to equal...

chemistry
How many phases and components are present in a saturated solution of Na2so4 with excess of solid is present at equilibrium with its vapour in a closed vessel

CHEMISTRY
What is the root-means square speed of Sulfur Dioxide gas at 345.0K?

chemistry
3a.How many electrons are predicted to be in the 4p orbital of a bromine (Br) atom? 5 b.How many of these electrons are predicted to be unpaired? 5

Chemistry
If 42 mL of Cr2O7-2(aq) solution is titrated to the endpoint with 172 mL of 0.15 M Cl-, what was the concentation of Cr2O7-2 solution? I got the reaction 14 H+(aq) _ Cr2O7-2(aq) + 6 Cl- = 2 Cr+3(aq) + 3 Cl2(g) + 7 H20(l) Now I have drawn a blank. Please help!

chemistry
If 35 mL of H2SO4 is titrated to the equivalent pint with 45 mL of 0.30M NaOH, what is the molarity of the H2SO4 before and after the reaction?

chemistry
If you titrated 50 mL of HCl and 50 mL H2SO4, each of the same molarity, with NaOH. What is the numerical ratio of the volume of NaOH required for HCl compared to that for H2SO4?

chemistry
Carbon dioxide gas is predicted to diffuse _______ times faster than sulfur dioxide gas under the same conditions.

chemistry
In the predicted electron configuration of Molybdenum (Mo), how many electrons are in the 4d subshell? 2. How many electrons are in the 4d subshell of the Molybdenum (III) ion?

Chemistry
An electron is in the 5f orbital. What are the values or sets of values for… a. The principle quantum number (n)? b. The angular momentum quantum number (l)? c. The magnetic quantum number (ml)?

college chemistry
The equilibrium constant for the reaction Sr(s) + Mg2+(aq) <---> Sr2+(aq) +Mg(s) is 3.69 x 10^17 at 25 C. Calculate Ecell for a cell made up of Sr/Sr2+ and Mg/Mg2+ half cells.

chemistry
why photosynthesis is considered as endothermic?

Chemistry
Use the data in the table to calculate the equilibrium constant for the following reaction. HCOOH(aq)+ OH −(aq) equilibrium reaction arrow HCOO−(aq)+ H2O(l) HCOO is 5.9e-11 (Kb) HCOOH is 1.7e-4 (Ka) Not sure how to find the equilibrium constant given this information

Chemistry
If 2.5x10^-3 moles of O2 were produced in the reaction, how many grams of H2O2 had to react?

physics/chemistry:sir steve drbob222 steve steve
A crystal is grown by evaporating A and 8 type atoms, and then letting them condense to form the crystal. If, because of the forces involved, on A atom is twice as likely to stick to the crystal OS a B atom, what is the probability that the final crysta pls show step i dont know

Chemistry
Oxalic acid , HOOCCOOH (aq) , is a diprotic acid with Ka1= 0.0560 and Ka2=0.0145. Determine the [-OOCCOO-] in a solution with an initial concentration of 0.139 M oxalic acid. HOOCCOOH(aq) = HOOCCOO-(aq) + H+(aq) HOOCCOO-(aq) = -OOCCOO-(aq) + H+(aq) I have tried a ICE diagram: ...

Chemistry
Oxalic acid , HOOCCOOH (aq) , is a diprotic acid with Ka1= 0.0560 and Ka2=0.0145. Determine the [-OOCCOO-] in a solution with an initial concentration of 0.139 M oxalic acid. HOOCCOOH(aq) = HOOCCOO-(aq) + H+(aq) HOOCCOO-(aq) = -OOCCOO-(aq) + H+(aq) I have tried a ICE diagram: ...

Chemistry
how much energy is released during the reaction of 2.5l diboron hexahydride with 5.65l chlorine gas?

Chemistry
How much heat is required to raise the temperature of 25g of aluminum from 25.0 C to 100 C? Convert this value to joules?

Chemistry
35.0mL of 0.050 M HCl is titrated with 0.050 M NH3 (Kb= 1.8 x 10^-5). The pH of the analyte solution after 15.0mL addition of NH3 titrant is?

Chemistry
A gas diffuses 3.98 times slower than H2 at the same temperature and pressure. What is the molar mass of the gas?

Chemistry
Please someone explain the best way of solving this. A 55 kg woman has 7.5 x 10 to the power of negative 3 moles of hemoglobin (Molar mass=64,456 g/mole) in her blood, how many hemoglobin molecules is that? What is the quantity in grams?

Chemistry
Calculate the mass f CaCo3, in Kg, needed to slurry to extract the SO2 present in 10m3 of industrial waste gases at rtp, if SO2 comprises 10% of this volume.

Chemistry
Identify the acid-base pairs in the following reactions HSO4^1-(aq) + OH^1- <==>SO4^2-(aq) + H2)(I)

Chemistry
1. The decomposition of acetaldehyde is a second order reaction with a rate constant of 4.71 × 10^−8 L/mol/s. What is the instantaneous rate of decomposition of acetaldehyde in a solution with a concentration of 5.55 × 10^−4 M? 2. The rate constant for the first-order ...

Chemistry
What is the pH of the solution if 0.015 mol of HCl is added to a buffer containing 0.014 mol of RCOOH and 0.033 mol of RCOONa (source of RCOO-)? Ka = 2.8E-5 I have tried the following: adding 0.014 + 0.015 = 0.029 ph = pka + log (Base/Acid) pH = -log(2.8E-5) + log(0.033/0.029...

Chemistry
heating cyclopropane (C3H6) converts it to propene (CH2=CHCH3). The rate law is first order in cyclopopane. If the rate constant at a particular temp is 6.22x10^-4 s^1 and the concentration of cyclopropane is held at .0300 mol/L, what mass of propene is produced in 10.0 min in...

Chemistry
Arrange the following cations in order of decreasing size :Ra2+,Sr2+,Ca2+,Ba2+.Also explain it.

Chemistry
what volume of carbon dioxide is produced when 49.7g of calcium carbonate reacts completely according to the following reaction at 25C and 1atm? 25C=298K R= 8.31441 J K-1 mol-1 101325 x V= 49.7x8.31441x298 V= 49.7x8.31441x298 101325 =1.2153 m3 Please help am I even on the ...

Chemistry
How many liters of CO2 would be collected over water from the bomcustion of 35g of cyclohexane, if the gas is collected at a barometric pressure of 765 torr and a temperature of 303 K?

Chemistry
Which type of polyethylene has no side chains? A) LLDPE*** B) HDPE

Chemistry 151
Calculate the concentration in g/dm3 of HNO3 in solution A. (H=1; N=14; O=16; Na=23)

chemistry
(b) (i)The e.m.f. of the cell was measured as 0.62 volts. Taking the standard electrode potential of Cu/Cu2+ as = +0.34 volts, calculate the standard potential of the Co/Co2+ system. Be careful to indicate whether your answer is positive or negative. (ii) State the direction ...

chemistry
calculate the molality of a solution that has 1.02kg sucrose C12H22O11 dissolved in 554g water?

chemistry
What is the molality of a solution composed of 25ml og toluene C6H5CH3 ( density=0.866g/ml) in 75 ml of benzene ( density=0.879g/ml)

Chemistry
A 10 g sample of water at 24 Celsius is mixed with 30.0 g of water at 48 Celsius. Calculate the final temperature of the mixture assuming no heat loss to the surroundings. The specific heat of water is 4.18 j/g•C

Chemistry
A dye has a λmax = 460 nm (ε = 70,000 L/(mol*cm)). What is the concentration of dye in a sample whose absorbance at 460 nm is A = 0.350 in a cell with a path length of 1.00 cm (4 points) I have no idea how to do this.

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