Sunday
August 28, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
A current of 96.5 A is passed for 18 min between nickel electrodes in 500 mL solution of 2M Ni(NO3)2. The molarity of solution after electrolysis would be
Sunday, June 5, 2016 by Anushka

chemistry
Which of the following is not a part of the scientific method? A. hypothesizing B. experimenting C. observing D. proving D?
Sunday, June 5, 2016 by quick help needed

Analytical Chemistry
Could someone show me step by step how to solve this type of problem? I have to do several of them, and would love to understand what is actually happening! Thank you so much in advance, I appreciate your help and time! Calculate the weight percent of ascorbic acid in a tablet...
Sunday, June 5, 2016 by DeeDee

Chemistry
How many ammonia liters of ammonia gas are produced when 85 grams of liquid nitrogen completely react? N2 + 3H2 = 2NH3
Saturday, June 4, 2016 by Macario

Chemistry
For the equilibrium system below, which of the following would decrease the concentration of 𝑃𝐶𝑙3(𝑔)?​ 𝑃𝐶𝑙3(𝑔) + 𝐶𝑙2(𝑔) ↔ 𝑃𝐶𝑙5(𝑔) + 45𝑘&#...
Saturday, June 4, 2016 by Help:(

Chemistry
7. For the equilibrium system below, which of the following would increase the concentration of 𝐻2𝑂(𝑔)? 𝐶(𝑠) + 𝐻2𝑂(𝑔) + 131𝑘𝐽 ↔ 𝐶𝑂(𝑔) + 𝐻2(𝑔) a. ...
Saturday, June 4, 2016 by Urgent

Chemistry
One of the issues caused by acid rain is the lowering of pH of small lakes, which leads to the death of numerous aquatic fish and plant species. Calcium oxide, commonly known as lime, is frequently used to temporarily remediate lakes that have been acidified by acid rain. ...
Saturday, June 4, 2016 by John Lee

chemistry
aluminum sulfide reacts with water to form aluminum hydroxide and hydrogen sulfide a. balance the chem eqn for this rxn Al2S3+6H2O = 2Al(OH)3+3H2S b.how many g of water are needed in the rxn to produce al(oh)3? what is the formula i use here?? c. how many g of al(oh)3 are ...
Saturday, June 4, 2016 by shi

Chemistry Homework
Backpackers often use canisters of white gas to fuel a cooking stove’s burner. If one canister contains 2.45dL of white gas, and the density of the gas is 0.720g/cm3, what is the mass of the fuel in kilograms? So Volume=2.45dL(10L/1dL)=24.5L(1000/1)=245​00cm^3 D=m/v...
Friday, June 3, 2016 by Leo

Chemistry
What is the mobile phase in this experiment? A) 10% 6M NaOH and 90% acetone B) 10% 6M HCl and 90% acetone C) 10% 5M KCl and 90% methanol D) 10% 5M KCl and 90% acetone Gel electrophoresis is an example of which type of chromatography? A) Column chromatography B) Gas ...
Friday, June 3, 2016 by Jon Riley

Chemistry
How many ammonia liters of ammonia gas are produced when 85 grams of liquid nitrogen completely react? N2 + 3H2 = 2NH3
Friday, June 3, 2016 by Macario

chemistry
Suppose a substance has been prepared that is composed of carbon, hydrogen, and nitrogen. When 0.1156 gram of this compound is reacted with oxygen, 0.1638 gram of carbon dioxide (CO2) and 0.1676 gram of water (H2O) are collected. Assuming that all the carbon in the compound ...
Friday, June 3, 2016 by Chansa

chemistry
show by calculation of z the behavior of (.25 mole) gas sample at the following conditions (ideal or real)at temperature 100c 1-p=0.25 v=12
Friday, June 3, 2016 by kamal

Chemistry
The combustion reaction of propane is described by the reaction. C3H8 + 5O2 → 4H2O + 3CO2. How many moles of O2 are required to generate 3 moles of CO2? 2.5 moles 3 moles 4 moles 5 moles
Friday, June 3, 2016 by Wesley

Chemistry
How many ammonia liters of ammonia gas are produced when 85 grams of liquid nitrogen completely react? N2 + 3H2 = 2NH3
Friday, June 3, 2016 by Macario

chemistry
a compound or solute with molecular mass 36?
Friday, June 3, 2016 by Anonymous

chemistry
a compound or solute will molecular mass 36?
Friday, June 3, 2016 by kartik

Chemistry
How many electrons are present in 0.002 moles of O--?
Friday, June 3, 2016 by Abhinav

Chemistry/- Dr.Bob222
A voltaic cell consists of a Zn/Zn2+ half-cell and a Ni/Ni2+ half-cell at 25 C. The initial concentrations of Ni2+ and Zn2+ are 1.50 M and 0.10 M, respectively. a. What is the initial cell potential? My answer: 0.56 B b. What is the cell potential when the concentration of Ni2...
Thursday, June 2, 2016 by Nevaeh

chemistry
I was given the following problem: what is the normality of a solution containing 6 grams of H2SO4 in a 200ml solution? my teacher obtained a normality of 39normals while I took into account that I had two hydrogen free and obtained a result of 0.6 N, who's right?
Thursday, June 2, 2016 by Paul

Chemistry
a 0.20 mol/l solution of weak base hpo4 has a ph of 9. find the Kb
Thursday, June 2, 2016 by Dawn

Chemistry
A buffer was prepared by mixing 0.1 M ch3cooh with 0.1M ch3cooNa in the ratio 8:2. Calculate ph after the addition of 2mL of 0.1 M HCl? When you do the 8:2 ratio and add 2 mL of 0.1 M HCl, the buffer is gone and you are left with 1*10^-3 moles of ch3cooh. How would you ...
Thursday, June 2, 2016 by Bobby

chemistry
Calculate the loss in mass if 20.2g of KNO3 crystals was completely decomposed(K=39,N=14,O=16
Thursday, June 2, 2016 by Deborah

Chemistry
Check my answers 63. What type of bond links the monomers together in a polymer? Poly bond Covalent bond Ionic bond Hydrogen bond*** 64.What is the change in atomic mass when an atom emits a beta particle? decreases by 1*** increases by 1 decreases by 2 remains the same 65. ...
Thursday, June 2, 2016 by Kayla

Chemistry
The acetate buffer were prepared by mixing 0.1 M ch3cooh with 0.1M ch3cooNa in the ratio 8:2 and 2:8. Calculate the resulting ph after the addition of 2mL of 0.1 M HCl to 10 ml of buffer 8:2 and 4ml of 0.1 M NaOH to 10 ml of buffer 8:2.
Thursday, June 2, 2016 by Bobby

Chemistry
You are given Ka of carbonic acid is 4.3 x10^-7. This means that Carbonic acid is a good hydrogen-ion acceptor*** good hydrogen-ion donor poor hydrogen-ion acceptor poor hydrogen-ion donor
Thursday, June 2, 2016 by Kayla

Chemistry
Calculate the molality of a solution prepared by dissolving 225.5 g KNO3 in 825mL of water. Show your work
Thursday, June 2, 2016 by Kayla

chemistry
A certain first order reaction has a rate constant of 5.68 x 10–3 s–1 at 139°C and a rate constant of 8.99 x 10–1 s–1 at a temperature of 215°C. Ea = 111 kJ mol– q1) What is the value of the rate constant at 275°C? q2) ...
Thursday, June 2, 2016 by jane

Chemistry
Calculate the pH of a mixture of 20.0 mL of 0.150 M HCl and 10.0 mL of 0.300 M NaOH.​[7.00]
Thursday, June 2, 2016 by Sihle

Chemistry
98.4 * (1/2)^(19/3.8) = 3.075 g CH3COOH*** H2PO4^– LiOH NH3
Wednesday, June 1, 2016 by Kira

Chemistry
What is the one standard atmosphere of pressure in kilospascals 0 kPa 1 kPa*** 101.3 kPa 760 kPa
Wednesday, June 1, 2016 by Nikkie

Chemistry
Use an analogy from everyday life that can define the term half-life
Wednesday, June 1, 2016 by Nikkie

Chemistry
Why does the mass and charge of an alpha particle make it less penetrating than a beta or gamma? Discuss both the mass and the charge
Wednesday, June 1, 2016 by Nikkie

Chemistry
How can an element be artificially transmuted? Give an example that has an element and what it is transmuted into
Wednesday, June 1, 2016 by Nikkie

Chemistry
The radioisotope radon-222 has a half-life of 3.8 days. How much of a 98.4 g sample of radon -222 would be left after approximately 19 days?
Wednesday, June 1, 2016 by Nikkie

chemistry
In a certain experiment, the rate constant, k, was measured as a function of the temperature, T.  Two data points were as follows: (A) 25°C, 1.1 x 10–5 min–1, and (B) 225°C, 2.4 x 10-2 min–1. The student who performed the experiment then ...
Wednesday, June 1, 2016 by jessica

Chemistry
At 425°C, a reaction has a rate constant of 7.7 x 10–4 s–1 and has an activation energy of 275 kJ mol–1. What is the frequency factor? The answer is 2.9 x 1017 s–1 , I need help with working out I used arrhenius equation and rearranged ...
Wednesday, June 1, 2016 by jessica

Science - Chemistry
How many atoms in a diamond.
Wednesday, June 1, 2016 by Ebony

Chemistry - Dr.Bob
Predict the half-reactions occurring at the anode and the cathode for the electrolysis of aqueous Na2SO4.
Wednesday, June 1, 2016 by Nevaeh

Chemistry
When the ratio of neutron-to-proton dictates that a neutron must break down it will form a helium nucleus an alpha particle a proton and an electron*** Two protons
Wednesday, June 1, 2016 by James

Chemistry
Which of the following materials is necessary to stop gamma radiation one foot of concrete single sheet of paper thin pieces of wood three inches of lead***
Wednesday, June 1, 2016 by James

chemistry
what are the products of a concentrated hydrochloric acid if inert electrodes are used
Wednesday, June 1, 2016 by Anonymous

chemistry
What quantity of CaCO3 (limestone) on heating will give 112g of CaO?
Wednesday, June 1, 2016 by sadaf

Chemistry
What's the formula for Li2Co3+Co(NO3)3(aq) ->
Wednesday, June 1, 2016 by Johnny

Chemistry
Identify the compound and classify its functional group in the image H H H H H H H-C-C-C-O-C-C-C-H H H H H H H
Wednesday, June 1, 2016 by Holly

Chemistry
a 0.20 mol/l solution of weak base hpo4 has a ph of 9. find the Kb
Wednesday, June 1, 2016 by Dawn

Chemistry
How do i calculate the pH of 0.0020mol/l HCl
Wednesday, June 1, 2016 by Buck

Chemistry
Why are the molecules of hydrocarbons nonpolar? The intermolecular attractions are strong. The electron pair is shared almost equally in all the bonds. All the bonds are single covalent bonds*** Van der Waals forces overcome polarity
Wednesday, June 1, 2016 by Abby

Chemistry
Balance the following redox equation using the oxidation number change method. Describe each step that is involved Al(s) + PbSO4 - - > Al2(SO4)3 + Pb(s)
Wednesday, June 1, 2016 by Abby

chemistry
what are the products of a concentrated solution of magnesium chloride if the electrodes used are inert
Wednesday, June 1, 2016 by Anonymous

Chemistry
Tell how a voltaic cell works. Be sure to mention the various parts of the voltaic cell and what they have to do with how it works
Wednesday, June 1, 2016 by Evan

Chemistry
What is the standard cell potential of a cell made of theoretical metals Ms/Ma^+2 and Mb/Mb^+2 if the reduction potentials are -0.19V and -0.85 V, respectively? +0.66V -0.66V +1.04 V*** -1.04V
Wednesday, June 1, 2016 by Kristin

Chemistry
What symbol is used to show the standard reduction potential of an oxidation reaction in a half cell? The sub means what follows is a subscript So the 0 is a superscript and the sub is its subscript E^0 sub cell*** E^0 sub red E^0 sub oxid All of the above
Wednesday, June 1, 2016 by Kristin

Chemistry
To charge a lead storage battery you must apply a direct current to it. hold a magnet close to it. force alternating current through it.*** increase the pressure on it.
Wednesday, June 1, 2016 by Kristin

Chemistry
The volume of a gas is increased from 100mL to 250 mL by heating it.If the original temperture of the gas was 15.0°c what will be the final temperture in °c
Tuesday, May 31, 2016 by Mayra

Chemistry
Magnesium chloride hexahydrate has a density of 1.69 g/cm3. What is the volume in liters of 1.5 x10^2 pounds of MgCl2*6H2O? yes D=m/v into V=m/d, Do I need to find the formula mass of Magnesium chloride hexahydrate and change pounds into liters? Divide the found numbers and I ...
Tuesday, May 31, 2016 by Kim

Chemistry
In the zinc-copper cell, Zn(s) | Zn^+2(1M) || Cu^+2(1M) | Cu(s), which electrode is negative? Cu^+2 Cu(s) Zn(s)*** Zn^+2
Tuesday, May 31, 2016 by Samuel

Chemistry
What is the oxidation half reaction for the following equation: Cr2O7^-2 +Fe+2 - - > Cr^+3 + Fe^+3 Cr^+3 - - > Cr2O7^-2 Fe^+2 - - > Fe^+3 Fe^+3 - - > Fe^+2 Cr2O7^-2 - -> Cr^+3***
Tuesday, May 31, 2016 by Samuel

Chemistry
What is the reducing agent in the following reaction? 2K + S - - > K2S K*** S K2S None of these
Tuesday, May 31, 2016 by Samuel

chemistry
Some physical properties of water are shown below: melting point 0.0°C boiling point 100.0°C specific heat solid 2.05 J/g·°C specfic heat liquid 4.184 J/g·°C specific heat gas 2.02 J/g·°C ΔH° fusion 6.02 kJ/mol ΔH° ...
Tuesday, May 31, 2016 by Selena

Chemistry
How many moles of silver will be deposited from a silver (i) trioxonitrate (v) solution by 16.0g of copper (Ag=108,Cu=63.5)
Tuesday, May 31, 2016 by Gift

Chemistry
find the concentration of h3o in a .86mol/l solution of the weak acid H2O2 (kA=2.4x10-12)
Tuesday, May 31, 2016 by Buck

Chemistry
Find the concentrations of all species in a 0.10mol/l solution of NaOH
Tuesday, May 31, 2016 by Buck

Chemistry- Dr.Bob222
Using the Nernst equation, determine the diluted concentration for both cells. Show your work. Sn| Sn2+(diluted)||Cu2+|Cu Zn| Zn2+ ||Sn2+(diluted)|Sn
Monday, May 30, 2016 by Anonymous

Chemistry!!! PLZ PLZ HELP!!
Calculate the equilibrium amounts of each susbtance in the reaction below if an initial amount of 0.1 moles of H2 are brought together with an initial amount of 0.2 moles of I2 and then equilibrium is established at 900K. Kc at this temperature=70. H2 + I2 <-> 2HI
Monday, May 30, 2016 by Sabrina

Chemistry
A 25.0-g sample of sodium hydroxide is dissolved in 400.mL of water. What is the concentration of the solution?
Monday, May 30, 2016 by Mayra

chemistry
What particle is needed to complete this equation 14/7N+ _______=14/7C+ 1/1H I think it is a beta particle because of beta decay and transmutation. I could be really off because this chapter is really confusing me.
Monday, May 30, 2016 by lulu

Chemistry- Dr.Bob222
Which metal could you use to reduce Cr3+ ions but not Mn2+ ions? Which metal could you use to reduce ions but not ions? Zn Mg Ni Al
Monday, May 30, 2016 by Anonymous

Chemistry
Write short note on sigma bond and pi bond
Monday, May 30, 2016 by Anonymous

Chemistry
Write on the physical properties of benzene
Monday, May 30, 2016 by Anonymous

Chemistry
Using benzene as an example to illustrate substitution reaction
Monday, May 30, 2016 by Anonymous

Chemistry
Define indicators giving four examples and their PH ranges
Monday, May 30, 2016 by Anonymous

Chemistry
Consider the compounds 4-tert-butylcyclohexanol and 4-tert-butylcyclohexanone. Using silica gel plates, which of the two compounds will have the higher Rf value when ethyl acetate is the developing solvent? Which will have the higher Rf value when dichloromethane is the ...
Monday, May 30, 2016 by Anon

chemistry
the ph of the resulting solution when 1.15g of sodium metal is reacted slowly in 500cm3 of water is close to
Monday, May 30, 2016 by durshetti balaji

chemistry
A) what is the molar fraction of each gas in a mixture of 6g of hydrogen H2 and 7g of nitrogen N2 ? B) what is the total pressurd exerted by the above mixture in a volume of 15 l at a temperature of 0ºc ? C) what is the partial pressure of each gas in the above mixture? R...
Monday, May 30, 2016 by angy

Chemistry
Which amount of heat is released when 75.0 g of water at 0° C is frozen to ice?
Sunday, May 29, 2016 by G

Chemistry
A flexible plastic container contains 0.833 g of helium gas in a volume of 18.3 L. If 0.203 g of helium is removed at constant pressure and temperature, what will be the new volume?
Sunday, May 29, 2016 by Anonymous

chemistry
If I have a sample from doing a half lfe lab with m&ms, not timed, just pulling out decayed or m&ms with rhe m on top, how do I calculate the half life using t1/2=(.693)/k formula. Do I have to do this 9 times as it took 9 trys to use up all the m&ms. I am not really sure what...
Sunday, May 29, 2016 by lulu

Chemistry
A flexible plastic container contains 0.833 g of helium gas in a volume of 18.3 L. If 0.203 g of helium is removed at constant pressure and temperature, what will be the new volume?
Sunday, May 29, 2016 by Anonymous

Chemistry
Consider a 500mL solution containing 2.0×10^-5 mol HCl ·what is the pH of the above solution? ·If the solution is diluted to 1.5 L what will be the new pH?
Sunday, May 29, 2016 by Mayra

Chemistry
A sample of oxalic acid (H2C2O4, with two acidic protons), of volume 37.09 mL was titrated to the stoichiometric point with 22.41 mL of 0.163 M NaOH(aq). What is the molarity of the oxalic acid? Answer in units of M.
Sunday, May 29, 2016 by Andrea

Chemistry
A sample of sodium hydroxide of volume 11 mL was titrated to the stoichiometric point with 24.5 mL of 0.138 M HCl(aq). What is the initial molarity of NaOH in the solution? Answer in units of M.
Sunday, May 29, 2016 by Andrea

Chemistry
If the reaction 2H2O2 →2H2O+O2 has a 45% yield, what is the molarity of the H2O2 solution if 2.5 L of this solution pro- duces 150 g of O2?
Sunday, May 29, 2016 by Andrea

Chemistry
Suppose that 12.41 mL of 0.169 M NaOH(aq) was required to titrate 0.1579 g of an unknown acid (HX). What is the molar mass of the acid? Answer in units of g/mol.
Sunday, May 29, 2016 by Andrea

Chemistry
1. A sample of oxalic acid (H2C2O4, with two acidic protons), of volume 46.56 mL was titrated to the stoichiometric point with 17.06 mL of 0.297 M NaOH(aq). What is the molarity of the oxalic acid? Answer in units of M. 2. What mass of the oxalic acid was in the sample of the ...
Sunday, May 29, 2016 by Angelica

Chemistry
A compound has an empirical formula of CH2 and molecular mass of 84g. What is it's molecular formula?
Sunday, May 29, 2016 by Mayra

Chemistry
How many moles of a gas are present in 2.0L cylinder at 1.50 atmospheres and 17 degree's celcius?
Sunday, May 29, 2016 by Mayra

Chemistry
Write the formation equation for the ester that forms between propanoic acid and 1-pentanol. Include the names of the products and the structures for all substances involved.
Sunday, May 29, 2016 by Lily

chemistry
Suppose that 9.6 mL of 1.5 M KOH(aq) is transferred to a 250 mL volumetric flask and diluted to the mark. It was found that 31.5 mL of this diluted solution solution was needed to reach the stoichiometric point in a titration of 9.6 mL of a phosphoric acid solution according ...
Sunday, May 29, 2016 by jess

chemistry
QUESTION 4 Data Set 3: 47.65 mL of a standard 0.1000 mol L–1 HCl solution is used to titrate a 0.3827 g sample containing NaOH and other impurities. None of the impurities reacted with the HCl. What is the mass of NaOH in the sample? a. 0.1737 g b. 0.2103 g c. 0.1906 g d...
Sunday, May 29, 2016 by jess

Chemistry- Dr.Bob222
Using the Nernst equation, determine the diluted concentration for both cells. Show your work. Given that [Cu2+] and [Zn2+] are both 2M. Note: I know that the nernst equation is E= E*cell=(-0.0592 V/n)log Q where Q in this case are [Sn2+]/[Cu2+] and [Zn2+]/[Sn2+]. I think that...
Saturday, May 28, 2016 by Anonymous

Chemistry
What is the pH of a 0.05 M solution of acetic acid knowing that it was 2% ionized
Saturday, May 28, 2016 by Sidney

Chemistry- Dr.Bob222
Using the Nernst equation, determine the diluted concentration for both cells. Show your work. Given that [Cu2+] and [Zn2+] are both 2M. Note: I know that the nernst equation is E= E*cell=(-0.0592 V/n)log Q where Q in this case are [Sn2+]/[Cu2+] and [Zn2+]/[Sn2+]. I think that...
Saturday, May 28, 2016 by Anonymous

chemistry
the mole fraction of h2 in a mixture of h2 and ch4 is same as the mole fraction of c2h6in a mixture of c2h6 and c3h8 containing equal weight of c2h6 and c3h8 calculate mole fraction of ch4 in the mixture of h2 and Ch4
Saturday, May 28, 2016 by aakarshan

Chemistry
Calculate the pH of a solution prepared by dissolving 10.0 g of tris(hydroxymethyl)aminomethane ("tris base") plus 10.0 g of tris hydrochloride in 0.250 L of water. (a) What will be the pH if 10.5 mL of 0.500 M NaOH is added?
Saturday, May 28, 2016 by Sidney

chemistry
QUESTION 11 Information Set 1: Chromium (III) iodate has a Ksp at 25°C of 5.0 x 10–6. 125 mL of a solution contains 0.0050 mol L–1 Cr (III) ion. What is the molar solubility of chromium (III) iodate at 25°C? a. 8.4 x 10–2 mol L–1 b. 2.2 x 10–3 ...
Friday, May 27, 2016 by jess

Chemistry
Chromium (III) iodate has a Ksp at 25°C of 5.0 x 10–6. 125 mL of a solution contains 0.0050 mol L–1 Cr (III) ion. What is the molar solubility of chromium (III) iodate at 25°C? a. 8.4 x 10–2 mol L–1 b. 2.2 x 10–3 mol L–1 c. 6.3 x 10–...
Friday, May 27, 2016 by jess

Chemistry
Choose an alkane that is 6 to 10 carbon atoms in length. List the alkane's name and the other isomers you can properly draw and name. For example: Decane / isomer 2 methyl-Nonane. Do not guess. Draw out on paper then name for best results. Include the drawing of the alkane...
Friday, May 27, 2016 by Anonymous

Chemistry
The molar solubility of silver iodide in a 0.186 M potassium iodide solution is __________ M.
Friday, May 27, 2016 by Kat

Chemistry
Write a balanced net ionic equation to show why the solubility of Ca(OH)2(s) increases in the presence of a strong acid and calculate the equilibrium constant for the reaction of this sparingly soluble salt with acid.
Friday, May 27, 2016 by Kat

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Homework Help: Science