Sunday
December 4, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

chemistry
Cu+HNO2-Cu(NO3)2+NO solved by oxidation no. Method
Saturday, November 26, 2016 by sakul

Chemistry
h2po4(aq) + co34(aq) hco3 (aq) + hpo42 (aq)
Friday, November 25, 2016 by Adam

chemistry
if i have an isopropyl group and the a carbon with a methyl group on it, will the methyl protons be split by the isopropyl protons? (CH3)2---C-C-(CH3)
Friday, November 25, 2016 by Anonymous

chemistry NMR helpppp
really really need some help, been stuck on this for toooo long. Some Data: "A" triplet for 3H (2 neighbors) "B" quartet for 2H (3 neighbors) "C" singlet for 3H (no neighbors) "D" singlet for 2H (no neighbors) Alright here is what i have...
Friday, November 25, 2016 by Anonymous

chemistry
The number of unpaired electrons and the element for [Xe]6s24f145d7: I know the element is Iridium but I cannot figure out the unpaired electrons!
Friday, November 25, 2016 by Jordan

Chemistry
the solubility of aspartic acid in water is .500 g in 100 mL at 25 degrees C. If .251 g of aspartic acid is dissolved in 50. mL of water at 50 degrees C and let solution cool to 25 degrees C. is the solution supersaturated, saturated, or unsaturated. the solution was not ...
Friday, November 25, 2016 by Nicole

Chemistry
Why does the white precipitation turns dark when adding Na2S2O3 drop wise to AgNO3 sollution
Friday, November 25, 2016 by Pramodi

Chemistry
A reaction of hydrolysis of Ba(NO) in a net ionic form?
Friday, November 25, 2016 by Patricia

Chemistry
How long must a steady current of 4.0A flow through the electrolyte to coat a a steel spoon with 8.5g of nickel?
Thursday, November 24, 2016 by Zoila

Chemistry
Carbohydrates (such as C6H12O6) undergo combustion with oxygen to produce carbon dioxide and water. Living things use this reaction (a process called respiration) to produce energy. Determine the mass of carbohydrates consumed for every 0.300 mol of oxygen gas consumed during ...
Thursday, November 24, 2016 by Ryan

Chemistry
Carbohydrates (such as C6H12O6) undergo combustion with oxygen to produce carbon dioxide and water. Living things use this reaction (a process called respiration) to produce energy. Determine the mass of carbohydrates consumed for every 0.300 mol of oxygen gas consumed during ...
Thursday, November 24, 2016 by Ryan

AP Chemistry
Calculate the concentration of the constituentions in solutions of the following compounds in the following concentrations: (a) 0.45 M HBr, (b) 0.045 M KOH, (c) 0.0112 M CaCl2.
Thursday, November 24, 2016 by Phoebe

Chemistry
In the dehydrogenation of ethane two reactions take place: C2H6 => C2H4 + H2 C2H6 + H2 => 2CH4 The mass distribution of the product is: 27% C2H6; 33% C2H4; 13% H2; 27% CH4. 1. What was the conversion of C2H6 to CH4? 2. What was the yield of C2H4 expressed in kg of C2H4 ...
Thursday, November 24, 2016 by Hoang

Analytical chemistry
Calculate the expected concentrations of vitamin B6 and caffeine in the stock solution assuming exactly 0.0506 g of pyridoxine hydrochloride (vitamin B6) and 0.1253 g of caffeine are dissolved in a 100 mL volumetric flask.
Wednesday, November 23, 2016 by Angel

Chemistry
How would I make a 93.1% w/w solution from 96% sulfuric acid using volume
Wednesday, November 23, 2016 by Pam

Chemistry
A 2.00L flask was filled with 4.00 mol of HI at a certain temperature and given sufficient time to react. At equilibrium the concentration of H2 was 0.400 M. Find the equilibrium concentrations of I2 and HI and then find the Keq at this temperature 2HI(g) <-> H2(g) + I2(g)
Wednesday, November 23, 2016 by Jessica

chemistry
normality of a solution containing 2g sodium carbonate in 250mL solution
Wednesday, November 23, 2016 by silpa

chemistry
give the name of the process when anhydrous copper sulphate becomes wet
Wednesday, November 23, 2016 by augustine

Chemistry
A 30.0 mL sample of 0.165 molL?1 propanoic acid (Ka=1.3×10?5) is titrated with 0.300 molL?1KOH. Calculate the pH at 0, 5,10, at equivalence point, 1/2 of the equivalence point, 20, 25 mL of added base.
Tuesday, November 22, 2016 by Sam Dowen

chemistry
Changing 1 mol of Mg(s) and 1/2 mol of O2 (g) to gaseous atoms requires a total of approximately 150kJ of energy. The first and second ionization energies of Mg are 737kJ/mol and 1450kJ/mol respectively. The first and second electron affinities of Oxygen are -141KJ/mol and +...
Tuesday, November 22, 2016 by Insolvable question

Chemistry
Before small batteries were available, carbide lamps were used for bicycle lights. Acetylene gas, C2H2, and solid calcium hydroxide were formed by the reaction of calcium carbide, CaC2, with water. The ignition of the acetylene gas provided the light. Currently, the same lamps...
Tuesday, November 22, 2016 by Andrew

chemistry
State whether each of the following sets of quantum numbers is permissible for an electron in an atom. If a set is not permissible, explain why. (i) [1, 0, +1/2, +1/2] and (ii) [3, 2, 1, 1]
Tuesday, November 22, 2016 by biman

Chemistry
A student followed the procedure given in the lab exercise to determine the ascorbic acid content in a commercial vitamin C tablet. The students prepared the solution using a 0.460 g vitamin C tablet. The titration required 40.00 mL of the 0.005 M KIO3/KI solution to reach an ...
Tuesday, November 22, 2016 by R

Chemistry
How many moles of air must be pumped into a 4.8 L tire to give it the pressure of 47.1 psi at 25°C ? I'm not sure how to even start doing this problem.
Monday, November 21, 2016 by Amanda

Chemistry
Is "a color of solution becoming less intense due to dilution" maybe evidence of chemical reaction or not?
Monday, November 21, 2016 by Anonymous

Chemistry
Carbohydrates (such as C6H12O6) undergo combustion with oxygen to produce carbon dioxide and water. Living things use this reaction (a process called respiration) to produce energy. Determine the mass of carbohydrates consumed for every 0.300 mol of oxygen gas consumed during ...
Monday, November 21, 2016 by Ryan

Chemistry
8.8 g of iron(II) sulphide reacts completely with excess dilute hydrochloric acid. Calculate the volume of hydrogen sulphide evolved, measured at 18 º C and 729 mmHg pressure.
Monday, November 21, 2016 by Christopher Penner

Chemistry
A sample of carbon monoxide was collected over water at a total pressure of 752 torr and a temperature of 15°C. What is the pressure (in torr) of the carbon monoxide?
Monday, November 21, 2016 by Andrew

Chemistry Lab
So I have a lab exam tomorrow and our instructor said that one of the questions would be as follows: Prepare 100mL of 0.03 M Copper Sulfate, beginning from copper sulfate pentahydrate. Calculate the exact molarity to 3 sig figs. Alright so I understand how to prepare 100mL of ...
Monday, November 21, 2016 by Jake

Chemistry 20
a source of hydrogen is an important issue of hydrogen fuel cells are going to become useful in automobiles. What important perspective is missing?
Monday, November 21, 2016 by David

Chemistry 20
If 4.56 mol of zinc react with excess copper (ii) sulphate, how many moles of precipitate will be formed?
Monday, November 21, 2016 by David

chemistry
Explain why sodium carbonate against hydrochloric acid titration using phenophthalein titration do not go to completion but stop at the sodium hydrogen carbonate stage.
Monday, November 21, 2016 by Bright

Chemistry
What is the morality of a solution prepared by dissolving 10.60g of sodium trioxocarbonate (v) in enough distilled water to obtain 250.0 ml of a solution?
Monday, November 21, 2016 by Charles

Chemistry
1.654 of a hydrated acid H2C2O4.xH2O was dissolved in water and the soultion was made up to 250cm3 . 23.80cm3 of this solution required 25.00cm3 of 0.100moldm-3 NaOH to reach the end point. Identify the value of x and the formula of the hydrated acid H2C2O4.xH2Or.
Monday, November 21, 2016 by Jemma

Chemistry
To what pH should you adjust a standard hydrogen electrode to get an electrode potential of -0.122 V ? (Assume that the partial pressure of hydrogen gas remains at 1 atm.)
Monday, November 21, 2016 by L

Chemistry
How much calories does it take to raise the temperature of 225 g of H2O from 25 °C to 100 °C. (Specific heat of water 4.182 J/(g* °C)
Monday, November 21, 2016 by Turtel

Chemistry
A patient requires 0.012 g of painkillers available as a 15 mg/ml solution. How many ml should be administered?
Monday, November 21, 2016 by Turtel

chemistry
What volume of alcohol would you use if you needed 25.0 g? Density is 0.7855 g/ml at 20°C
Monday, November 21, 2016 by Jayel

Chemistry
In an aqueous solution containing a mixture of Zn2+and Mg2+, how would you determine their contents by means of EDTA titration?
Monday, November 21, 2016 by Silvia

Chemistry
5g of salt are dissolved in 200g of water,what mass of solution is this?
Monday, November 21, 2016 by Pine

Chemistry
Write a balanced overall reaction from these unbalanced half-reactions. Sn->Sn2+ Ag+->Ag Balanced overall equation I got Sn+2Ag+->Sn+2Ag, but its wrong.
Sunday, November 20, 2016 by angie

chemistry
For the following reaction KClO2->KCl+O2 assign oxidation states to each element on each side of the equation. Reactants K=? Cl=? O=? Which element is reduced? I got K=5, Cl=-1, and O=-4 . The element that reduced is K, but its says its wrong. Help, Please!
Sunday, November 20, 2016 by chris12

Chemistry
A 24 L welding tank contains of 285 bar of argon at 28 °C. Nitrogen is added to obtain an 80:20 argon:nitrogen mixture. a) What are the partial pressures of argon and nitrogen? b) What will be the total tank pressure?
Sunday, November 20, 2016 by Po

chemistry
Suggest a source of error (not already mentioned) that would result in a value of x that is a) higher than the actual value b) lower than the actual value
Sunday, November 20, 2016 by Anonymous

Chemistry 20
A student was experimentally checking the stoichiometry of a reaction. The student correctly predicted that the reaction should produce 1.82 g of al2(so4)3(s). When the student dried and weighed the al2(so4)3(s) produced, its mass was 1.94 g. The percent difference of the ...
Sunday, November 20, 2016 by Tala

Chemistry 20
When 1.2 x 10^-3 mol of nitric acid react with excess sodium carbonate, how many moles of carbonic acid are produced?
Sunday, November 20, 2016 by Tala

Chemistry 20
If 4.56 mol of zinc react with excess copper (ii) sulphate, how many moles of precipitate will be formed?
Sunday, November 20, 2016 by Tala

Chemistry
To increase the acidity of soil, you can add peat, which contains a complex acid mixture known as humic acid. The complexity of the humic acid makes it difficult to determine how acidic you are making the soil. You decide to use a titration to get a better measure. If ...
Sunday, November 20, 2016 by Julia

Chemistry
What are the major species in a solution during the titration of citric acid with a strong base such as NaOH?
Sunday, November 20, 2016 by Lyn

statistics and probabilities
Suppose you will be taking exams in English, statistics and chemistry tomorrow and from past experience you know that for each exam you have a 50% chance of receiving an A. List all the possibilities for receiving A's on various exams. Letting X represents the number of A...
Saturday, November 19, 2016 by rhinechilde

Dr.Bob Chemistry
Is HOET associated with E1 or E2? I think it is E2.
Saturday, November 19, 2016 by Sarah

Chemistry
An electron in the n = 10 state of a hydrogen atom emits a photon with energy of 6.54×10–20 J. What is the final state of the electron
Saturday, November 19, 2016 by Jason

chemistry
Suppose f??(x)=?36sin(6x) and f?(0)=?5, and f(0)=?3 f(?/3)=?
Friday, November 18, 2016 by angie

chemistry
Suppose f??(x)=?36sin(6x) and f?(0)=?5, and f(0)=?3 f(?/3)=?
Friday, November 18, 2016 by angie

Chemistry
If you used 50 grams of copper (II) oxide, how much copper would be produced. (Use the ratio)
Friday, November 18, 2016 by Kelly

Chemistry
What can you conclude about the relative equilibrium concentrations of CrO4 ion in each of the solutions 0.1M K2Cr2O7 and 0.1M K2CrO4?
Friday, November 18, 2016 by Skyler

Organic chemistry
Nitrobenzene + KOH >>>>> ???
Friday, November 18, 2016 by Amal

chemistry
If dissolving 2g of ionic salt causes 50ml of water in increase temp. by 15 degrees Celsius at constant pressure, what would be the change in temperature if 6g of the same ionic salt were used instead? Assume the volume of solution remains the same.
Friday, November 18, 2016 by tommy

CHEMISTRY
CALCULATE THE OSMOLARITY OF THE FOLLOWING ).1M KNO3 & ).35M Na3PO4 & 0.35
Thursday, November 17, 2016 by BOBBI

AP Chemistry
Consider 54.0 mL of a solution of weak acid HA (Ka = 10^-6), which has a pH of 4.140. What volume of water must be added to make the pH = 5.000? [HA]=((10^-4.14)^2)/(10^-6) = 0.0052480746 0.0052480746 x 54 = c x v c= ((10^-5)^2)/(10^-6) = 10^-4 v= (0.0052480746 x 54)/(10^-4) ...
Thursday, November 17, 2016 by Efrem

Chemistry
A laboratory technician wants to determine the aspirin content of a headache pill by acid–base titration. Aspirin has a Ka of 3.0 × 10-4. The pill is dissolved in water to give a solution that is about 10-2 M and is then titrated with KOH solution. Find the pH at ...
Thursday, November 17, 2016 by J

Qualitative analysis ( Chemistry)
A solution x forms a white precipitate with dilute sulfur in acid and also with aqueous silver nitrate. What could solution x contain? A) Barium Chloride B) Barium nitrate C) Magnesium chloride D) Magnesium chlorine Could someone tell me how to get the answer and explain it to...
Thursday, November 17, 2016 by Cheezel

Chemistry
How many moles of hydrogen from when 10 moles of methane react completely?
Thursday, November 17, 2016 by Marissa

Chemistry
How many moles of water vapor react to yield 546.234 moles of hydrogen?
Thursday, November 17, 2016 by Marissa

Chemistry
Write a conversion factor that could be used to convert between moles of methane and moles of hydrogen
Thursday, November 17, 2016 by Marissa

Chemistry
Calculate the amount of heat required to convert 155 g of ice at -10oC to steam at 110oC? (155g)x[0-(-10)]C x (.50cal/g x C) = 775cal (155g) x (80cal/g) = 12400cal (155g)x(100-0)C x (1.00cal/g x C) = 15500cal (155g) x (540cal/g) = 83700cal 775cal + 12400cal + 15500cal +...
Thursday, November 17, 2016 by Anonymous

chemistry
What amount of ice must be added to 540.0 g of water at 25.0 °C to cool the water to 0.0 °C and have no ice
Thursday, November 17, 2016 by KO

Chemistry
Explain the difference in acidity of MgO dissolved in water and of P4O10 in water in terms of position of the element in the periodic table and bonding. I found MgO is basic and P4O10 is acidic
Thursday, November 17, 2016 by Po

chemistry
A common way of producing hydrogen gas in the lab is by reacting zinc with hydrochloric acid. Zn (s) + 2 HCl (aq) -> ZnCl2 (aq) + H2 (g) A sample of impure zinc, of mass 5.10g, reacted with an excess of hydrochloric acid solution 3.0 mol dm-3 concentration. In the end 1.7dm...
Thursday, November 17, 2016 by Lois

NEED HELP MATH!!!!!!!
I DID ALLL THESE Welcome to Jiskha Homework Help! Post homework questions online and get free homework help from tutors. More than 200 tutors volunteer their time to help over 4,000 students with homework everyday. Students receive answers from teachers in various school ...
Thursday, November 17, 2016 by fudge

chemistry
The combustion of 1.00g of vitamin C, compound that contains only carbon, hydrogen and oxygen produced 1.500g of co2 and 0.401g of H2O. Find the molecular formula of vitamin C knowing that its molecular mass is 176
Thursday, November 17, 2016 by Lois

Chemistry
In the qualitative analysis scheme, magnesium and nickel precipitate from solution upon the addition of sodium hydroxide. Once separated from the remaining cations by filtration or decanting, the solid mixture is acidified and warmed to dissolve magnesium and nickel cations ...
Thursday, November 17, 2016 by Ashley

Chemistry
The chief compound in marble is CaCO3. However, marble is readily attacked by acids. a) Determine the molar solubility of marble (that is, [Ca2+] in a saturated solution). b) Determine the equilibrium constant for the overall reaction that occurs when marble reacts with acid. ...
Thursday, November 17, 2016 by Ashley

Chemistry
What are some classes of organic compounds that have unpleasant odors?
Thursday, November 17, 2016 by Denaiel

Chemistry
How to find grams used of methanol? The molecular weight in g/mol is 32.04 and the density is 0.791. Also 25 mL of methanol was used. How to convert this to grams?
Thursday, November 17, 2016 by Denaiel

chemistry
The fermentation of glucose to form ethanol occurs according to the following chemical reaction: C6H12O6(aq) ? 2 C2H5OH(l) + 2 CO2(g) A) If 700 grams of glucose (C6H12O6) are fermented, what is the maximum volume in milliliters of ethanol (C2H5OH) that can form? (Density of ...
Thursday, November 17, 2016 by abigail

chemistry
If 700 grams of glucose (C6H12O6) are fermented, what is the maximum volume in milliliters of ethanol (C2H5OH) that can form? (Density of ethanol is 0.79 g/mL)
Thursday, November 17, 2016 by abigail

Organic chemistry (QA)
In which solutions will a white precipitate be observed when aqueous copper (ii) chloride is added to it? A) Sodium hydroxide B) Potassium carbonate C) Lead (ii) nitrate D) Magnesium Sulfate Could someone tell me the ans and explain it to me, thk u!
Thursday, November 17, 2016 by Cheezel

Chemistry
Hydrogen gas is produced industrially by reacting methane gas, CH4 (g), with water vapor to from carbon monoxide and hydrogen gas. In a particular reaction, 25.5L of methane (measured at a pressure of 732 torr and a temperature of 25degree Celcius) mixes with 22.8 L of water ...
Thursday, November 17, 2016 by Cali234

Chemistry
Which gas has the greatest kinetic energy? a) neon at a temperature of 200k b) neon at a temperature of 300k c) neon at a temperature of 400k d) neon at a temperature of 500k e) neon at a temperature of 600k f) none of the above (they all have the same kinetic energy)
Thursday, November 17, 2016 by Cali234

Chemistry
A gas of unknown identity diffuses at a rate of 83.3 mL/s in a diffusion apparatus in which carbon dioxide diffuses at the rate of 102 mL/s. Calculate the molecular mass of the unknown gas. Give your answers in units of g/mol to three significant figures.
Thursday, November 17, 2016 by Cali234

Chemistry
How many moles of ozone does the atmosphere hold? For a sense of scale,compare the amount to the total carbon dioxide emitted annually from fossil fuel burning, cement production and deforestation (7900 Tg/C). Given with the facts the amount of ozone is equivalent to a 3mm ...
Thursday, November 17, 2016 by Nayo

Chemistry
For gaseous n-pentane and isopentane, both at 298K, ?Gf°=?194.4kJ/mol and?200.8kJ/mol, respectively. The vapor pressures of the liquids are given by: n-pentane:log10P(atm)=3.9714?1065/T?41 isopentane:log10P(atm)=3.9089?1020/T?40 Calculate (a) KP for the isomerization in ...
Wednesday, November 16, 2016 by Joesph

Chemistry Heat Capacity
Is ?CP for the reaction > 0 or < 0? Would an atmosphere of 20% carbon dioxide, 5% carbon monoxide, and 75% nitrogen oxidize nickel at 1000K? It is given that ?G° = -66.62 KJ/mol, ?H° = -48.93 kJ/mol, and ?S = 17.69 J/ mol K
Wednesday, November 16, 2016 by Joesph

Chemistry
Determine the mass of NH2CH2CO2Na and the volume of 0.150 M HCl solution required to make 1.35 L of a buffer solution at pH=10.75 and at a total concentration of 0.33 M. pKa(NH2CH2CO2H)=9.88. a.Mass of NH2CH2CO2Na: b. Volume of HCl solution: Hi Im sooo confused. 9.88=10.75+log...
Wednesday, November 16, 2016 by J

Chemistry
Sample A: Solid appearance:crystals, solids, white Solid Conductivity:no Solubility: soluble Solution appearance:substance disappears slowly Solution Conductivity: yes Relative melting point:2nd Sample B: Solid appearance:brown, tiny solids, dirt appearance Solid Conductivity...
Wednesday, November 16, 2016 by Sarah

Chemistry
Calculate the standard enthalpy change for the reaction 2A+B?2C+2D Use the following data: Substance ?H?f (kJ/mol) A -247 B -375 C 191 D -483 Express your answer to three significant figures and include the appropriate units. My answer was 285 kJ/mol but mastering Chemistry ...
Wednesday, November 16, 2016 by Marquel

Chemistry
In need of help setting up each of these problems. Under the conditions in a laboratory experiment, 0.0513 grams of aluminum (At. Wt.=27.0) was reacted with excess hydrochloric acid to produce hydrogen gas according to the following balanced equation: 2 Al+ 6 HCL -> 2 AlCl3...
Wednesday, November 16, 2016 by Anonymous

chemistry
(2.00x10?)?³
Wednesday, November 16, 2016 by Dee

Chemistry
if the total partial pressure of Ne and He having the same mass in a sealed container is 6atm then what is that of Ne?
Wednesday, November 16, 2016 by Ousman

Chemistry
pressure of Ne in sealed container
Wednesday, November 16, 2016 by Ousman

Chemistry
What is the maximum mass of cobalt (II) phosphate that will precipitate from a solution prepared by adding an excess of K3PO4 solution to 100.0 mL of 5.0 M CoCI2? Sorry for all the confusion with different names we are working in a group and its easier to keep track who's ...
Wednesday, November 16, 2016 by Marissa

Chemistry
Explain how a ligand can be both sigma donating and pi donating and give an example of a ligand that does both. Is this ligand a Lewis acid or a Lewis base?
Wednesday, November 16, 2016 by Tenshi

Chemistry
A hydrogen atom in the ground state absorbs a photon with a wavelength and after it release a photon with a second wavelength. On which orbital will drop the electron?
Wednesday, November 16, 2016 by Felicien

chemistry
How much heat is absorbed if 45 grams of sweat is evaporated from someone's skin? ?Hvap for water at body temperature is 2.41 kJ/g.
Wednesday, November 16, 2016 by marcquel

Chemistry
Hydrogen gas is used for many purposes, including the hydrogenation of vegetable oils to make margarine. The most common industrial process for producing hydrogen is "steam reforming", in which methane gas, CH4, from natural gas reacts with water vapor to form carbon...
Wednesday, November 16, 2016 by Lily

Chemistry
An antacid contains 200mg of aluminum hydroxide and 200 mg of magnesium hydroxide per capsule. How many moles of aluminum hydroxide does each capsule contain? What is the mass in milligrams of 0.0734 mole of magnesium hydroxide?
Wednesday, November 16, 2016 by Lily

Chemistry
Explain the difference in acidity of MgO dissolved in water and of P4O10 in water in terms of position of the element in the periodic table and bonding. I found MgO is basic and P4O10 is acidic
Wednesday, November 16, 2016 by Po

Science (Stoichiometry with Gasses) (Chemistry)
If 1.00 kg of methane (CH4) is burned completely (in excess O2) and the CO2 produced is collected at 20°C and 1.00 atm, what volume (L) will this CO2 occupy??
Wednesday, November 16, 2016 by Ray

CHEMISTRY
WHAT IS THE IUPAC NAME OF CH2(OH)CH2(OH)
Wednesday, November 16, 2016 by ROCHEL

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