Thursday
September 29, 2016

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

Chemistry
Describe how lead(II) iodide cen be prepared in the laboratory
Tuesday, August 2, 2016 by Aaron

Chemistry
Rearrange the titration calculation to find Mb in a solution. If I put 13.2 mL of NaOH and 0.3 mL of phenolphthalein in 25 mL of KHP, what is the Mb of the solution? The original solution of NaOh is 100 mL and is composed of 1.069e-15 moles of H+, 9.445e-2 moles of OH-, and 9....
Tuesday, August 2, 2016 by Jenny

Chemistry
sample of silver metal is suspected to be contaminated with zinc. A 0.2365 g portion of this metal is dissolved in nitric acid and the silver ions precipitated with excess aqueous NaCl. After filtering and drying, the mass of the precipitate is found to be 0.2865 g. What was ...
Tuesday, August 2, 2016 by Damon

Chemistry
Mercury has a melting point of - 38. 9°C. what would this read in degrees Fahrenheit the and kelvin
Tuesday, August 2, 2016 by Ruth Ekada

Chemistry
The following soluble salts are strong electrolytes. For each, write a balanced equation for their dissociation in water. NaBr BaBr2 Li3PO4
Tuesday, August 2, 2016 by Katie

Chemistry
If the pH of a 0.46 M aqueous solution of a weak base is 9.2, estimate the Kb of the base:
Monday, August 1, 2016 by Damon

analytical chemistry
what is the solubility of PbI2in g/L ,if the solubility product is 7.1 ?
Monday, August 1, 2016 by Uzma Jan

analytical chemistry
the solubility product of Bi2S3 is 1.0 and that of HgS is 1.0. which one is the least soluble under a given temperature 6
Monday, August 1, 2016 by Uzma Jan

chemistry
Consider the titration of 40.0 mL 0.250 M ethylamine, C2H5NH2, with 0.350 M HCl. Determine each of the following and sketch the titration curve. Kb of ethylamine = 5.6x 10-4 a. The volume of added acid required to reach the equivalence point. b. The initial pH. c. The pH when ...
Sunday, July 31, 2016 by danna

chemistry
what amount of ammonium chloride that will separate out when 55g of its solution at 373k is cooled to 273k(solubility at 373k -55g and at 273k - 37g)
Sunday, July 31, 2016 by anamika

Chemistry
1.5mL of a 0.05M solution of calcium chloride (CaCl2) was diluted with water to a volume of 10L. What was the concentration of Cl- ions in the diluted solution in ppm.
Sunday, July 31, 2016 by Rav

Chemistry
What is Anta basic substance?
Sunday, July 31, 2016 by Utsav

chemistry
In which direction, on ceiling, floor or walls, the pressure exerted by air in a room will be maximum. Justify your answer
Saturday, July 30, 2016 by Anonymous

Chemistry
An antifreeze solution is prepared containing 40.0 g of ethylene glycol (molar mass = 62.0 g/mol) in 60.0 g of water. Calculate the freezing point of this solutions A.-20.1°C B.0.518°C C.20.1°C D.120.1°C
Saturday, July 30, 2016 by Jessie

Chemistry
Write chemical formulas for the compounds formed by the following positive and negative ions: Ba2+ and NO3-, Al3+ and Co3, and K+ and PO43-
Saturday, July 30, 2016 by Kelly

Chemistry
If you start with 4.00 moles of C3H8 (propane) and 4.00 moles of O2, how many moles of carbon dioxide can be produced?
Friday, July 29, 2016 by Kelly

Chemistry
Electrochemistry In the electrolysis of aqueous copper(II) bromine CuBr2(aq, 1.00 g of copper is deposited at the cathode. How many grams of bromine are produced at the anode?
Friday, July 29, 2016 by sarah simpson

Chemistry
What are 2 allotropes of carbon? Could you please compare the physical and chemical properties....
Friday, July 29, 2016 by Sarah

Chemistry
How do you determine the polarity of a substance? Example?
Friday, July 29, 2016 by George

Chemistry Theory
We are able to "see" the shapes of molecules with X-ray crystallography. However, even without this technology, there is a great deal of evidence that water, H2O, is a bent, polar molecule. Discuss this evidence and explain how it relates to our model of the water ...
Friday, July 29, 2016 by Katie

chemistry
Using dissociation constants from Appendix D in the textbook, determine the value for the equilibrium constant for each of the following reactions. (Remember that when reactions are added, the corresponding equilibrium constants are multiplied.) (i) HCO−3(aq)+OH−(...
Friday, July 29, 2016 by sayuri

Chemistry
Downlad Project
Friday, July 29, 2016 by Project

Chemistry
if the solubilty of AgC2H3O2 is 5.0 x10^-2mol/L. What is the Ksp?
Friday, July 29, 2016 by Kevin

Chemistry
if 1.7L of a saturated solution of AgC2H2O2 is found to contain 14.1g of AgC2H3O2. What is the Ksp of AgC2H3O2?
Friday, July 29, 2016 by Shirley

Chemistry
A voltaic cell, with Ecell = 0.180 V at 298K, is constructed as follows: Ag(s)|Ag+(satdAg3PO4)||Ag+(0.135 M )|Ag(s) What is the Ksp of Ag3PO4?
Friday, July 29, 2016 by LC

Chemistry 12th
How can you prepared to benzo phenol from phenyl magnetium bromide
Friday, July 29, 2016 by Chemistry

Chemistry
Calculate the pH of the buffer formed by mixing 50.0mL of 0.200 F NaH2PO4 with 50.0mL of 0.120 F HCl
Friday, July 29, 2016 by Wynona Genesis

Chemistry
A 50.0 mL solution with analytical concentration of 0.100M in HClO4and 0.080M in formic acid is titrated with 0.200M KOH. Calculate the pH after addition of the following volumes of titrants: a) 0.0, b)20.0, c) 25.0, d)35.0, e)45.0, f)50.0
Friday, July 29, 2016 by Wynona Genesis

Chemistry
A glass of water contains 1.2 x 1024 molecules of water. An additional 4.0 moles of water are poured into the glass. How many moles of water are in the glass?
Thursday, July 28, 2016 by Kelly

chemistry
How to solve CoCl2+HO2- ------> Co(OH)3+ Cl- by half reaction method
Thursday, July 28, 2016 by Pratik Rathi

Chemistry
C2D3 has a solubility product constant of 9.14×10−9. What is the molar solubility of C2D3? Express your answer with the appropriate units.
Thursday, July 28, 2016 by Damon

Chemistry
How many grams of Nitrogen contains same number of neutrons as 6grams of 12C?
Thursday, July 28, 2016 by Anurag Barman

Chemistry
How much heat is produced by the complete reaction of 5.29 kg of nitromethane?
Thursday, July 28, 2016 by Isaac

General Chemistry
what is the value of Kc if PbCl(s)=1.5g, [Pb2+]=1.6*10^-2 M and [Cl-] =3.2*10^-2 M at equilibrium? (The molar mass of PbCl(s) is 278 g/mol and its density is 5.85g/cm^3.)
Thursday, July 28, 2016 by Anonymous

Chemistry
What is the concentration of a monoprotic weak Acid if its pH is 5.50 and its Ka= 5.7 x 10^-10?
Thursday, July 28, 2016 by Joshua

Chemistry Grade 12
If the concentration of I^-1 is found to be 2.4 x 10^-3 mol/L in a saturated solution of PbI2. What is the Ksp of PbI2?
Thursday, July 28, 2016 by Kevin

Chemistry
Why wash water in experiment limiting reagent has to be kept warm at 80-90 degree celcius . Explain why
Thursday, July 28, 2016 by Uitm

Chemistry
I need to draw a line angle structure of ibuprofen that shows hydrogen bonding and I am stuck. Can anyone help?
Wednesday, July 27, 2016 by Breanne

Chemistry
You discover a new cell type that contains measurable amounts of silver ions (Ag+) in it. You find that the concentration of Ag+ inside the cell is still 10 times lower than the concentration outside. Calculate the amount of membrane potential that results from this amount of ...
Wednesday, July 27, 2016 by Tenshi

Organic Chemistry
Is helium considered a noble gas?
Wednesday, July 27, 2016 by Anonymous

Chemistry Grade 12
If the concentration of CN1- is found to be 1.4 × 10-6 mol/L in a saturated solution of AgCN, what is the Ksp of AgCN?
Wednesday, July 27, 2016 by Kevin

chemistry
15gm of sodium chloride is present in one kilogram of solution.express the concentratiom in ppm and ppb
Wednesday, July 27, 2016 by hussain

chemistry
what volumes of 6M hcl and 2M hcl should be mixed to get two litres of 3M hcl
Wednesday, July 27, 2016 by hussain

Chemistry
If 0.896g of a gas occupies a 250mL flask at 20 degree celcius and 760 mmHg of pressure, what is the molar mass of the gas?
Wednesday, July 27, 2016 by John

chemistry
what volume of a 0.5M solution of sulphuric acid is required to prepare 2 litres of a 0.4M solution of the acid
Wednesday, July 27, 2016 by Apoorva

chemistry
15mg of sodium chloride is present in 1kg of solution. express the concentration in ppm and ppb.
Wednesday, July 27, 2016 by Apoorva

Chemistry
Rank the following molecules in order of water solubility. ch3ch2ch2ch3, ch3oh, nacl, and ch3chohcooh
Tuesday, July 26, 2016 by Steph

chemistry
Dissolve 50g of sodium hydroxide in 1 litres and determine the normality
Tuesday, July 26, 2016 by Maryann

Chemistry
How much H3PO4 is needed to neutralize 1 liter of a 0.75M solution of NaOH? (in moles)
Tuesday, July 26, 2016 by Damon

Chemistry
Which value is most likely to be the pH of a salt that is formed by the reaction of a strong acid and a weak base
Tuesday, July 26, 2016 by RESHONDA

Chemistry
When zinc metal is reacted with hydrochloric acid, zinc chloride and hydrogen gas are produced. If 25ml of 0.2M HCl and 0.3g of zinc metal is used: a. how many M of zinc chloride will be produced? b. how many M of zinc chloride will be produced if 0.5M of HCl was used? c. how ...
Tuesday, July 26, 2016 by Eirin

Chemistry
What volume of nitrogen dioxide (in L) is produced from the complete reaction of 16.87 of lead (ii) nitrate at STP
Monday, July 25, 2016 by Damon

Chemistry
How much oxygen will we get from 120 grams of KClO3?
Monday, July 25, 2016 by Siam

Organic Chemistry
Why is helium considered a noble gas?
Monday, July 25, 2016 by Sevret

Chemistry
250ml solutions is prepared on dissolving 20g NaOH. Calculate the molarity of solution
Monday, July 25, 2016 by Diwaker

12th grade Chemistry
BOND BREAKING AND BOND MAKING: Determine by calculations and energy level diagrams, to proof whether these two reactions are endothermic or exothermic reactions.. 1. Methane burns in oxygen 2. Nitrogen (II) reacting with oxygen producing nitrogen monoxide.. please anyone just...
Sunday, July 24, 2016 by Barachiel

Chemistry
Why Fe(III) can be estimated in acidic medium by dicromet not by permanganet? — please give answer basis on value of reduction potential
Sunday, July 24, 2016 by yeasin

Chemistry
Determine by calculation and diagrames to proof whether these two reactions are endothermic or exothermic .. 1. Methane burns in oxygen 2. Nitrogen (II) reacting with oxygen producing nitrogen monoxide.
Sunday, July 24, 2016 by Barachiel

chemistry
pH of 1.0 x 10-8 M RbOH
Sunday, July 24, 2016 by Richard

chemistry
Nylon 88 is made from the monomers H2N(CH2)8NH2  and  HOOC(CH2)6COOH.  So, would you characterize nylon 88 as rather an addition or a condensation polymer? Please explain your answer
Sunday, July 24, 2016 by Chem

chemistry
Vanadium is an environmental pollutant originating from some types of steel, but also from the combustion of fossil fuels. The amount of V2+ in an unknown sample is determined by potentiometric titration by 7.62 mM permanganate ion, MnO4 - . 25.00 mL of unknown was titrated ...
Saturday, July 23, 2016 by siri

chemistry
You can temporarily receive relief from acid indigestion by using an antacid that contains a base. Why is it not a good idea to use an antacid routinely? (2 reasons)
Saturday, July 23, 2016 by Lara

Analytical Chemistry
I am having major issues with this problem and I no clue where to start. It also doesn't help that the professor never taught us how to calculate mass % from data like this... Students in the analytical chemistry class were given a sample of spinach to determine its iron ...
Friday, July 22, 2016 by Katie

Chemistry
A solution of 0.211 M NaOH is used to titrate 24.0 mL of a H2SO4 solution. If 19.0 mL of the NaOH solution is required to reach the endpoint, what is the molarity of the H2SO4 solution? H2SO4(aq)+2NaOH(aq)→2H2O(l)+NaSO4(​aq)
Friday, July 22, 2016 by Ava

Chemistry
Static charge can interfere with the production of plastic products by attracting dust and dirt. to reduce it, manufacturers expose the area to polonium-210, which has a half-life of 138 days. How much of a 25.0-g sample will remain after one year (365 days)? N = N0(1/2)t/T...
Thursday, July 21, 2016 by S

chemistry
how much ml of oxalic acid is needed to standardize 0.1M NaoH
Thursday, July 21, 2016 by Megha Sivadas

chemistry
molar solubility of nitrogen at 25 degree celcius
Thursday, July 21, 2016 by ahmed yousif ali

Math
In a group of 500 students, 150 are studying physics, 220 are studying biology, and 100 are studying chemistry. At least 25 students are studying more than one of these sciences. What is the greatest possible number of these students that might NOT be studying any of these ...
Wednesday, July 20, 2016 by Anonymous

Chemistry
For two questions below, first write and balance the equation for the chemical reaction.  Please, also review the material in Chapter 8, if you will feel you might need it in order to answer the questions.  Next, please answer the following questions: (a) ...
Wednesday, July 20, 2016 by Chem&Society

Chemistry
Express each aqueous concentration in the unit indicated. 45 ppm NO3 -, as molarity of nitrate ion in [mol NO3 - /L].
Wednesday, July 20, 2016 by Chem&Society

Chemistry
The atmosphere contains about 5.2 x1015 t of air.  What mass in metric tons of carbon dioxide is in the atmosphere if the concentration of CO2 is 395 ppm?
Wednesday, July 20, 2016 by Chem&Society

Chemistry
For the system, H2(g) + X2(g) <--> 2HX(g), Kc = 24.4 at 300 K. A system was charged with 2.00 moles of HX in a 3.00 liter container. The catalyst was introduced using a remote unit, and the system was allowed to come to equilibrium. How many moles of H2(g) will be ...
Wednesday, July 20, 2016 by Val

chemistry
Assuming all gases are at the same temperature and pressure, how many milliliters of hydrogen gas must react to give 41.0 mL of NH3? 3H2(g)+N2(g)→2NH3(g)
Wednesday, July 20, 2016 by Maria

Chemistry
How many grams of hydrogen peroxide (H2O2) must be added to 1,500 ml of water to produce a concentration of 1.33 m (molal solution)?
Wednesday, July 20, 2016 by Damon

Chemistry
For the teaction system, 2SO2(g) + O2(g) <--> 2SO3(g), Kc has a value of 4.62 at 450.0K. A system, at equilibrium, has the following concentrations: [SO3] = 0.254 M, [O2] = .00855 M. What is the equilibrium concentration of SO2(g)? The correct answer is 1.28M, but I don...
Wednesday, July 20, 2016 by Mikey

Chemistry
The human body obtains 885 kJ of energy from a chocolate chip cookie. If this energy were used to vaporize at 100 degree Celsius, how many grams of water could be vaporized? The heat of vaporization of water at 100 degrees Celsius is 40.7 kJ/mole.
Wednesday, July 20, 2016 by Jane

chemistry
The compete oxidation of 2g of an aldehyde A by acidified potassium chromate produces 2.1g of carboxylic acid B which is dissolved in 50 ml of distilled water . The obtained solution reacts with exactly 1.05 g of solid lime to form salt C a) Write the equation of the reaction ...
Wednesday, July 20, 2016 by dani

Chemistry
How many liters of HCl acid needed to dissolve at 1 ton of carbon and how long would it take?
Wednesday, July 20, 2016 by Derrick

Chemistry
How many grams of O2 are there in a 50.0L tank at 21*C when the pressure is 1.19x10^4mmHg?
Tuesday, July 19, 2016 by Brooke

Chemistry
The human body obtains 885 kJ of energy from a chocolate chip cookie. If this energy were used to vaporize at 100 degree Celsius, how many grams of water could be vaporized? The heat of vaporization of water at 100 degrees Celsius is 40.7 kJ/mole.
Tuesday, July 19, 2016 by Jane

Chemistry
At constant pressure , a certain gas occupies 80cm3 at 0 degrees, what wil be its volumd at 10 degrees
Tuesday, July 19, 2016 by Max

chemistry
what happens to water at 100 degrees celsius as pressure is increased fro 0.8 atm to 1.2 atm?
Tuesday, July 19, 2016 by barb

Chemistry
The boiling point of alcohol is 78.3 degrees Celcius at 760 mm atm pressure. Would the boiling point be higher or lower than 78.3 degree Celcius at hugher altirudes? Why?
Tuesday, July 19, 2016 by Chen

Chemistry
If 30ml of the standard sodium edetate soln neutralized 25ml of solution containing 0.25g of dried magnesium sulphate. Calculate the %w/v of mgso4 in the dried mgso4
Tuesday, July 19, 2016 by Kingsley Ekpe

CHEMISTRY
A compound which contains hydrogen, oxygen, carbon only has molar mass of about 85 g/mol. When 0.43 g of the compound is burned in excess of oxyfen, 1.10 g of CO2 and 0.45 g of H2O are formed. Find the molecular formula and the empirical formula of the compound
Monday, July 18, 2016 by Clive Lodnyx

chemistry
Hydrogen chloride reacts with water to produce an ion with the chemical formula H3O+. An H3O+ ion has one dative covalent bond. Explain how the bond is formed.
Monday, July 18, 2016 by Rose

Chemistry
For each of the following combinations of solutions, determine the mass of barium sulfate, BaSO4, that should precipitate...? For each of the following combinations of solutions, determine the mass of barium sulfate, BaSO4, that should precipitate. (Begin by writing a chemical...
Monday, July 18, 2016 by Juliet

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of Na2O completely reacts. Assume that there is more than enough of the other reactant. Na2O(s)+H2O(l)→2NaOH(aq)
Sunday, July 17, 2016 by Javier

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of Mg completely reacts. Assume that there is more than enough of the other reactant. 2Mg(s)+O2(g)→2MgO(s)
Sunday, July 17, 2016 by Leo

Chemistry
For the reaction, calculate how many grams of the product form when 3.2 g of CaO completely reacts. Assume that there is more than enough of the other reactant. CaO(s)+CO2(g)→CaCO3(s)
Sunday, July 17, 2016 by Rachel

Chemistry
For the reaction shown, calculate how many grams of oxygen form when each of the following completely reacts. 2HgO(s)→2Hg(l)+O2(g)
Sunday, July 17, 2016 by Marley

chemistry
what is the precipitate form of 2naoh+cuso4->na2so4+cu(oh)2
Sunday, July 17, 2016 by charshley

Chemistry
A CaCl2 solution is given to increase blood levels of calcium. If a patient receives 5.0 mL of a 5.0 % (m/v) CaCl2 solution, how many grams of CaCl2 were given?
Sunday, July 17, 2016 by Ava

Chemistry
A typical antacid contains CaCO3. If such an antacid is added to 25.0 mL of a solution that is 0.250 M in HCl, how many grams of CO2 gas are produced?
Sunday, July 17, 2016 by Maria

Chemistry
A patient received 5.0 g of NaCl in 8 hours. How many milliliters of a 0.40 % (m/v) NaCl (saline) solution were delivered?
Sunday, July 17, 2016 by maria

chemistry
what will be formed when oxygen combines with hydrogen in the presence of hydrated iron 3 oxide?
Sunday, July 17, 2016 by stephen

chemistry
Calculate the grams or milliliters of solute needed to prepare the following solutions. 1.)75. g of a 7.0 % (m/m) KCl solution 2.) 1250 mL of a 8.0 % (m/v) NH4Cl solution 3.) 270. mL of a 15.0 % (v/v) acetic acid solution I really just need to know how to work the first ...
Sunday, July 17, 2016 by maria

chemistry
Solubility (g/100gH2O) Substance 20∘C 50∘C KCl 34.0 42.6 NaNO3 88.0 114.0 C12H22O11 (sugar) 203.9 260.4 Using the above table, determine whether each of the following solutions will be saturated or unsaturated at 50 ∘C. 1.) Adding 19.7 g KCl to 35.0 g H2O 2.)...
Sunday, July 17, 2016 by maria

chemistry
a 51.6 litre sample of a pure allotrope of oxygen has a mass of 100.0 grams. (25 degrees celsius and 100 kPa) Show, by calculation, which allotrope of oxygen is present.
Sunday, July 17, 2016 by Anonymous

Chemistry
Write a balanced equation for the complete oxidation reaction that occurs when ethanol (C2H5OH) burns in air.
Sunday, July 17, 2016 by anonymous

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Homework Help: Science