Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
We are given that the solubility product of platinum (II) sulfide is 9.9x10^-74 We are told to write a balanced equation for dissolving platinum (II) sulfide. I put : PtS(S) <> Pt^2+(aq) + S^2-(aq) and then we had to write the Ksp expression: Ksp=[Pt^2+][S2-] The the ...

chemistry
plz help me with the frequency factor value and activation energy value of diammonium phosphate production.

Chemistry
A system has an initial energy of 117 joules. The energy equation includes --40.1 J of heat and -20.3 J of work. What is the final energy? Was heat added to the system or to the environment? Was work done by the system or to the system? Be sure to show all of your work and ...

chemistry
What is the molality of a solution consisting of 34.0 mL of benzene (C6H6; d = 0.877 g/mL) in 187 mL of hexane (C6H14 ; d = 0.660 g/mL)?

Chemistry
Give the formal charge on the sulfur atom in a Lewis structure for the sulfate ion in which every atom satisfies the octet rule. Based off my lewis structure, I think the formal charge of the the sulfur atom would be +2. Is that correct?

Chemistry
The complementary base sequence in the RNA bound to a DNA strand with the base sequence shown below would be ____________________. -C-C-G-A-T-T- A) -G-G-C-T-A-A- B) -A-A-U-C-G-G- C) -C-C-G-A-T-T- D) -G-G-C-U-A-A-

Chemistry
A DNA template having the base sequence A-G-A-T-G-A would produce a mRNA with a base sequence of ______. A) A-G-A-T-G-A B) U-C-U-A-C-U*** C) T-C-T-U-C-T D) T-C-T-A-C-A E) A-C-A-U-C-A

ap chemistry
write a balanced equation if 18.0g go nitrogen gas reacts with excess oxygen gas at STP to form nitrogen dioxide gas

chemistry
Calculate the mass of marble chips that produce 20 grams of carbon (iv) oxide .when reacted with dilute hydrochloric acid (c=12,O=16,Ca=40)

Chemistry
1. Weight loss from quick-weight-loss diets is generally loss of __________. A) fat B) carbohydrates C) muscle D) water*** 2. What is the recommended maximum percentage of a persons calorie intake should come from saturated fats? 0-5% 15-18% 7-10%*** 20-25%

chemistry
A student weighs out a 14.4 g sample of copper(II) bromide, transfers it to a 500 mL volumetric flask, adds enough water to dissolve it and then adds water to the 500 mL tic mark. What is the molarity of CuBr2 in the resulting solution The answer I keep getting is completely ...

Chemistry
A 0.4671g sample containing sodium bicarbonate (a mono acidic base) is dissolved and titrated with standard solution of HCl acid requiring 40.72cm^3. ( the HCL was standardized by titrating 0.1876NaCO3 which required 37.86cm^3 of acid). Calculate the percent NaCO2 in the sample

Chemistry
The half life of a radioactive material is 120 months. How much of this material will be left after 350 months if the initial concentration is 2.40M?

Chemistry
The measured pH of a 0.100M solution of NH3(aq) at 25C is 11.12. Calculate Kb for Nh3(aq)at 25C.

Chemistry
How many grams of ice would be melted by the energy obtained as 16.2 of steam is condensed at 100 degrees celsius and cooled to 0 degrees celsius? I would like to know how it's done step by step.

chemistry
1. The first order rate constant for the reaction, SO2Cl2(g) → SO2(g) + Cl2(g), is 2.20 x 10-5 s-1 at 593 K. What percent of a sample of SO2Cl2 would be decomposed by heating at 593 K for (a) 1 hr, (b) 3 hr. How long will it take for half of the SO2Cl2 to decompose?

Chemistry
net ionic equation to show that sulfurous acid, H2SO3, behaves as an acid in water. I got this answer but do not know if it is correct. H2SO3 + H2O --- H3O + SO I am Not sure if its is tri/mono/diprotic

Chemistry
The voltage generated by the zinc concentration cell described by, Zn(s)|Zn2 (aq, 0.100 M)||Zn2 (aq, ? M)|Zn(s) is 24.0 mV at 25 °C. Calculate the concentration of the Zn2 (aq) ion at the cathode. How would I go about this problem? I am extremely confused :/ Thank you so much...

Chemistry
The voltage generated by the zinc concentration cell described by, Zn(s)|Zn2 (aq, 0.100 M)||Zn2 (aq, ? M)|Zn(s) is 24.0 mV at 25 °C. Calculate the concentration of the Zn2 (aq) ion at the cathode. How would I go about this problem? I am extremely confused :/ Thank you so much...

Chemistry
In a reaction Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq), 6.00 g of Mg was present at 0.00 min. After 3.00 min, 4.50 g of Mg remained. Express the average rate as mol of Mg consumed per minute. I was taught how to use molarity but this question does not tell me molarity, just ...

Chemistry
Show the steps needed to determine the energy in a red photon of 7.0 x 10^2 nm. E= h * (c/λ) 6.62e-34 * (3e8/2e-7) 2.837e-19 J? Is this correct?

Chemistry
Consider the reaction: 2CH4(g) + 3O2(g) + 2NH3(g) --> 2HCN(g) + 6H2O(g) If 203.5 g NH3 is reacted with excess CH4 and O2, what mass in grams of HCN can be produced?

chemistry
what volume of carbondioxide is produced when 10g of Hcl reacts completely with caco3 caco3+2HCl=cacl2+H2o+Co2 moles ofHCl=10/36.5=0.27 volume:volume 2HCl:CO2 2:1 24000*2:24000 480000:24000 2700:x x=1350cm3

Chemistry
Perpare 500ml of 1M HCl solution from a bottle of concentrated 37%(W/W) HCL stock with a density of 1.19g/ml. 37%= 37/100 x 100 therefore mass is 37g molarity = mol/vol 1= mol/0.5 mol=0.5 mass of Hcl needed = molxmr mass = 0.5 x 36.5 mass = 18.25g

Chemistry
The solubility of Agcl with solubility product 1.6 × 10^-10 in 0.1 M Nacl solution will be ?

chemistry
How do you know if a compound is predicted to be polar or non-polar? Especially if they use imaginary elements as examples?

Chemistry
Do all salts conduct electricity in water? Why or why not?

Chemistry
Three bottles lost their labels. One contained an aqueous solution of HCl, another an aqueous solution of HNO3, and the third contained an aqueous solution of H2SO4. Write an experimental procedure that would allow you to correctly identify the contents of the bottles using ...

Chemistry
Three bottles lost their labels. One contained an aqueous solution of HCl, another an aqueous solution of HNO3, and the third contained an aqueous solution of H2SO4. Write an experimental procedure that would allow you to correctly identify the contents of the bottles using ...

Chemistry
A possible set of quantum numbers for the last electron added to complete an atom of potassium in its ground state is a) n=4, l=0, ml=0, ms= -1/2 b) n=3, l=1, ml=0, ms= -1/2 c) n=4, l=1, ml=0, ms= +1/2 d) n=3, l=1, ml=1, ms= +1/2 e) n=4, l=2, ml=1, ms= +1/2 I want to say the ...

Chemistry
Calculate the ph of a solution that is 0.2M In NH3 and 0.3M in NH4Cl we find that the acid dissociation constant ka for NH3 is 5.7×10^-10

Chemistry
What is the molarity of a solution containing 1.23g of LiOH in enough water to give a final volume of 380ml? I know the MW of Li is 6.941, O is 15.9594 and H is 1.00794. Using this info the number of mols in 1.23g of LiOH is 0.05144

Maths, physics, chemistry,
The weight of H2C2O4.2H2O required to prepare 500 ml of 0.2N solution is a)126g b)12.6g c)63g d)6.3g

Chemistry
What is the molar mass of feso4 . 7h2o

chemistry
water cannot cook beans on the moon.explain

chemistry check
Calculate the pH of:0.01M HCl pH=-log[H*]. ..=-log[0.01]. ..=2.is the pH of HCl,I enter -log on my calculator Igot 2 as my answer,Am I using the right step of formular?

chemistry
4Fe2(S)+ 11H2O(g) to give 2Fe2O2

chemistry
The oxidation number of sulphur in CuSO4.5H2O is ......

Chemistry
In the gas-phase reaction given below, the [I2] changes from 0.400 M at 0.00 min to 0.200 M at 3.00 min. I2 + Cl2 --> 2 ICl Calculate the average reaction rate in moles I2 consumed per liter per minute. mol/(L·min)

Organic Chemistry
(i can't upload an image so i have to explain the spectrum) My spectrum has peaks at 0.85 ppm (integration = 1.49) 1.2 ppm (integration = 7.93) 1.5 ppm (integration = 1.11) 3.6 ppm (integration = 1) the only one that shows clear peaks is the one at 3.6 ppm, which appears to be...

Chemistry
Draw the structure of the tripeptide “Asp-Ala-Ile” at pH = 1. Then determine the total charge of the tripeptide. The side chain of each amino acid is shown below in the form at pH = 7. (So when you use them to answer this question, you might need to modify the structures ...

Chemistry
When the element A is burned in an excess of oxygen, the oxide A2O3(s) is formed. 0.5386 g of element A is treated with oxygen and 0.711 g of A2O3 are formed. Identify element A.

chemistry
A 40.0-mL sample of 0.100 M HNO2 is titrated with 0.200 M KOH. Calculate the volume required to reach the equivalence point (in mL)

Chemistry
Give the formal change on the sulfur atom in a Lewis structure for the sulfate ion in which every atom satisfies the octet rule. 6 v.e - 4 v.e. = formal charge of +2?

Chemistry
Which one of the following compounds does not follow the octet rule? a) NF3 b) CF4 c) SF4 d) PH3 e) HCl I know I can eliminate A and B because nitrogen and carbon follow the octet rule. I know I can eliminate E because the total amount of valence electrons in HCl is 8. I am ...

chemistry HELP
a flask containing 50ml of 0.128M sodium acetate is titrated with 0.138M nitric acid. Calculate the initial ph of the acetate solution and calculate the ph after the addition of 24.9ml of nitric acid. pKa for acetate 4.757

chemistry
A S.T.P.how many litres of hydrogen can be obtained from the reaction of 500cm3 of 0.5M H2SO4 with excess zinc metals?(molar volume of H2 at stp=22.4dm3).

Chemistry
The solubility of Chromium (II) Hydroxide is .0035g/100mL - Calculate the solubility product of Chromium (II) Hydroxide. I know that we have to find Ksp. but i do not understand how to make the Ksp equation to calculate the solubility product, if it is already given to us...

Chemistry grade 11
Okay I've got a HUGE chem test tomorrow and I desperately need help! Please help!!!! 73. Hematite (Fe2O3) and magnetite (Fe3O4) are two ores used as sources of iron. Which ore provides the greatest percentage of iron per kilogram? 78. A hydrate contains .050 mole of H2O to ...

Chemistry
Temperature values are used to determine relative vapor pressure in compounds. Explain principles involved that allows temperature and vapor pressure to be related in this fashion. I understand the type of liquid and intermolecular forces are involved. But, I do not understand...

Chemistry
What is the difference between a diprotic and triprotic acid? How does each acid ionise in water?

Chemistry
In 2-3 sentences, describe how propanoic acid (C2H5COOH) and propanoate anion (C2H5COO-) can be used to make a buffer solution if the Ka of propanoic acid is 1.34 x 10-5.

chemistry
Product of this reasction? 1. Ag(NH3)2Cl + HCl? 2. AgOH + NaOH? 3. PbCl2 + HCl? 4. Pb(OH)2 + NaOH? 5. PbSO4 + (CH3COO)NH4? 6. Hg^2+ + HCl + H2S? 7. Cu^2+ + HCl + H2S? 8. Cu^2+ + KSCN? 9. Fe^2+ + NH4OH + NH4Cl + H2S? 10. Fe^2+ + NaOH? 11. Fe^2+ + K4Fe(CN)6? 12. Fe^2+ + K3Fe(CN)...

Chemistry
The reaction, N2O5 = 2NO2+1/2O2 is first order in N2O5 with rate constant 6.2 x 10^-4 s^-1. What is the value of rate of reaction when [N2O5] = 1.25 mol L^-1 s^-1 ?

chemistry
Product of this reasction? 1. Ag(NH3)2Cl + HCl? 2. AgOH + NaOH? 3. PbCl2 + HCl? 4. Pb(OH)2 + NaOH? 5. PbSO4 + (CH3COO)NH4? 6. Hg^2+ + HCl + H2S? 7. Cu^2+ + HCl + H2S? 8. Cu^2+ + KSCN? 9. Fe^2+ + NH4OH + NH4Cl + H2S? 10. Fe^2+ + NaOH? 11. Fe^2+ + K4Fe(CN)6? 12. Fe^2+ + K3Fe(CN)...

Chemistry
Does CH2CH2CH2CH2CH2CH2CH2 represent the polymer segment polyethylene?

Chemistry
What is the pH of a solution prepared by mixing 100. mL of 0.0500 M HCl with 300. mL of 0.500 M HF? [Ka(HF) = 7.1 × 10–4] I believe that I'd use M1V1 + M2V2 = M3V3 but I don't know where to go after that. Thanks!

Chemistry
Explain the difference between a diprotic and triprotic acid. How does each acid ionise in water? - I understand the difference between a diprotic and triprotic acid, though I haven't found how each acid ionises in water through extensive research. Thanks.

chemistry
some pollutants in natural waters such as heavy metal and organic compounds would be classified as having low solubility.what are some origins of pollutants in natural waters? if some are low solubility compounds, why are these a problem? Hello, I just don't understand what it...

Chemistry
Based on the following equation: 2AgNO3 + CaCl2 > 2AgCl + Ca(NO3) When 50 g AgNO3 are combined with 1.45M CaCl2 solution, what volume of the 1.45M CaCl2 solution would be needed to precipitate all of the silver as AgCl?

Chemistry
Calculate the solubility of ZnCO3 in a buffer solution with a pH of 9.83 and Ksp of 1.2x10^-10

Chemistry
Calculate the ZnCO3 in a buffer solution with a pH of 9.83

Biology
Mrs. Eryth is carrier of the sex-linked hemophilia allele, and Mr. Eryth is normal (as far as blood chemistry goes). A. Draw a Punnet square that shows the theoretical genotypes and phenotypes among their children. B. They actually have 4 male and 4 female children; how many ...

Chemistry
Estimate the value of deltaGf for COCl2(l) at 25 degrees celcius

Chemistry
How would I balance the following redox equation? I know the Charge on the Br is 5, but i am comfused on where to go from there. H20 + Br^- + Al^3+ -> Al + BrO3^- + H^+ Thank you so much in advance

Chemistry
The quantity of antimony in a sample can be determined by an oxidation-reduction titration with an oxidizing agent. A 7.79-g sample of stibnite, an ore of antimony, is dissolved in hot, concentrated HCl(aq) and passed over a reducing agent so that all the antimony is in the ...

Chemistry
Calculate the cell potential for the following reaction as written at 25.00 °C, given that [Cr2 ] = 0.875 M and [Ni2 ] = 0.0100 M. I keep on getting the answer .42 which is incorrect. Thank you so much in advance!

Chemistry
Choose the most polar bond from the options given below. a) B-O b) B-S c) C-N d) C-O

Chemistry
In a given experiment 36.44 mL of NaOH were required for neutralize a solution of HCl 0.35 M. Calculate the moles of NaOH present to neutralize the HCl in the titration.

chemistry
Calculate the molar solubility of BaSO4 in a solution in which [H3O+] is 0.50 M. Ksp(BaSO4) = 1.1×10-10, Ka(HSO4-)=1.02×10-2

Chemistry
Why is the selenate ion, SeO42−, is more stable in aqueous solution than is the tellurate ion, TeO42-?

physical chemistry
Estimate the boiling point of 250 cm3 of water to which 12.6 g of phenol(C6H5OH) has been added. Treat the solution as ideal.( water of boiling point elevation is 0.51K/mol)

chemistry
Draw a complete Lewis Structure (showing all bonds and lone pairs) for a molecule with the general formula AX4, if A was from group 4A and X was from group 7A

Chemistry
An experiment requires 0.3 M NH3(aq). The stockroom manager estimates that 15 L of the base is needed. What volume of 15 M NH3(aq) will be used to prepare this amount of 0.3 M base? Answer in units of mL

chemistry
You have a tank of argon gas at 19.80 atm pressure at 19°C. The volume of argon in the tank is 50.0 L. What would be the volume (in liters) of this gas if you allowed it to expand to the pressure of the surrounding air (0.924 atm)? Assume the temperauter remains constant.

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 ?

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Homework Help: Science