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January 23, 2017

Homework Help: Science: Chemistry

Recent Homework Questions About Chemistry

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 ...
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...
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...
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&...
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

Chemistry
The mass of lead bromide that is dissolved in 250 mL of a saturated solution is____ grams.
Friday, May 27, 2016 by Kat

Chemistry
The solubility of Mg(OH)2 is measured and found to be 9.25×10-3 g/L. Use this information to calculate a Ksp value for magnesium hydroxide
Friday, May 27, 2016 by Kat

Chemistry
“How fast do hummingbirds fly?” Why is the question a scientific question?
Friday, May 27, 2016 by Deon

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&...
Friday, May 27, 2016 by jess

chemistry
A buffer is prepared consisting of 0.75 mol of sodium dihydrogenphosphate, NaH2PO4, and 0.60 mol of sodium hydrogenphosphate, Na2HPO4, dissolved in 600.0 mL of water. The Ka for the dihydrogenphosphate ion is 6.2 x 10–8 at 25°C. Which of the ...
Friday, May 27, 2016 by jess

chemistry
Calculate the volume of the ammoniacgas formed when nitrogen reacts with 6 litres of hydrogen
Friday, May 27, 2016 by divya

Chemistry
Complete the following equations: A) methyl butanone + oxygen ---> B) a pentagon + F2 ----->
Thursday, May 26, 2016 by Rose

Chemistry
What would the reaction of these two look like (reactants and products) A) hexanal is reduced B) Butanoic acid is neutralized by potassium hydroxide
Thursday, May 26, 2016 by Rose

Chemistry Help Please!
1) You are going to make 1800ml of a 25uM solution using a compound whose MW= 60.06 Daltons. How many grams do you need of this compound? Give your answer with four decimal places. 2) You are going to make 300ml of a 75mM solution using a compound whose MW=818 g/mole. How many...
Thursday, May 26, 2016 by Tenshi

Chemistry
If Ka for HNO2,=4.5x10-4, find the [H+] a 0.9 M HNO2 solution.
Thursday, May 26, 2016 by Kathy

Chemistry
In a hydrogen- oxygen fuel cell hydrogen diffuses through the cathode. hydrogen and oxygen are mixed before entering the anode.*** oxygen diffuses through the anode. oxygen diffuses through the cathode.
Thursday, May 26, 2016 by Katie

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.
Thursday, May 26, 2016 by Katie

General Chemistry
A 1/5 mmol (yes, millimol... no, it isn't a typo_ sample of XeFn h as a mass of 0.311 g. What is the value of n? The answer is 4, but why?
Thursday, May 26, 2016 by Kayla

chemistry
How to calculate number of electrones in 18 ml of water givan that density of water is 1g/cc
Thursday, May 26, 2016 by anu mol

chemistry
How many grams of CO2 are evolved on heating 200 g of CaCO3.
Thursday, May 26, 2016 by anu mol

Chemistry
Why must not the condensed water drip into the flask?
Wednesday, May 25, 2016 by Vaisamoa Tokauea

Chemistry
When it comes to something being spontaneous, what does it mean? I know its something that goes out without no outside force or something like that but what are example of something that is spontaneous ?
Wednesday, May 25, 2016 by Kat

Chemistry
What is the change in enthalpy of the following reaction? 2NaBr(aq) + PbCl2(aq) 2NaCl(aq) + PbBr2(aq) Given: NaCl: ∆H = -411 kJ NaBr: ∆H = -360 kJ PbCl2: ∆H = -359 kJ PbBr2: ∆H = -277 kJ Im lost with this. Everytime I try to do it, it doesn't come ...
Wednesday, May 25, 2016 by Kat

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, May 25, 2016 by Genna

Chemistry
In the most common dry cell what material is the electrode that is the center rod made of? copper graphite iron*** zinc
Wednesday, May 25, 2016 by Genna

Chemistry
What assures that there is no charge build up in a voltaic cell as oxidation and reduction occur? one of the half cells the electrolyte solutions*** the moving electrons the salt bridge
Wednesday, May 25, 2016 by Genna

Chemistry
aluminum hydroxide is decomposed to form aluminum oxide and water. if 2.23 moles of water are formed then how many of aluminum oxide are formed. how many grams of aluminum hydroxide must have been.decomposed?
Wednesday, May 25, 2016 by Alisha

Chemistry
The bond angle of water is decreased from 109Degree 28' to 104Degree 24',why?
Wednesday, May 25, 2016 by Pappu kumar sah

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***
Wednesday, May 25, 2016 by Lara

Chemistry
Of the following metals, which ions are most easily reduced? aluminum*** iron mercury potassium
Wednesday, May 25, 2016 by Lara

Chemistry
Which atom has a change in oxidation number of –3 in the following redox reaction? K2Cr2O7 + H2O + S - - > KOH + Cr2O3 + SO2 Cr^+3 - - > Cr2O7^-2 Fe^+2 - - > Fe^+3 Fe^+3 - - > Fe^+2 Cr2O7^-2 - -> Cr^+3***
Wednesday, May 25, 2016 by Lara

Chemistry
what happens in a condensation reaction head-to-tail joining of monomers side-by-side joining of monomers cross-linking of monomers*** substitution of halogen
Wednesday, May 25, 2016 by Amy

chemistry
add any reducing agent to kmno4+k2cr2O7+k1 and reconcile the charges and equations
Wednesday, May 25, 2016 by omowhe

Chemistry
At 100 degrees C, pure H2O has a vapor pressure of 760 torr. An aqueous solution has a concentration of 1.90 M MgCl2. The van't Hoff factor is 2.45. The density of the solution is 1.09 g/mL. Calculate the vapor pressure of the solution.
Tuesday, May 24, 2016 by Ayaka

Chemistry
A 1.0L of an aqueous solution of ethylene glycol, HOCH2CH2OH, is 60% HOCH2CH2OH by mass and has a density of 1.15 g/mL. Calculate the morality of the solution.
Tuesday, May 24, 2016 by Ayaka

chemistry
A 2.00 L flask is filled with propane gas (C3H8)at 1.00 atm and -15.0 Degrees Celsius. What is the mass of the propane in the flask?
Tuesday, May 24, 2016 by Anna

CHEMISTRY
WHEN THE PH IS 0.4 WHAT IS THE COLOUR OF THE INDICATOR
Tuesday, May 24, 2016 by APY QUEEN

CHEMISTRY
USING EQUATION SHOW HOW AQUEOUS SOLUTION OF HYDROCHLORIC ACID CONTAINING HYDROXONIUM ION NEUTRALISED POTASSIUM HYDROXIDE
Tuesday, May 24, 2016 by APY QUEEN

CHEMISTRY
WHEN THE PH IS 4.0 WHAT IS THE COLOUR OF THE INDICATOR
Tuesday, May 24, 2016 by APY QUEEN

CHEMISTRY
THE BASICITY OF TETRAOXOSULPHATE6 ACID IS 2.EXPLAIN THE STATEMENT WITH EQU SHOWING REACTION BTW ACID&POTASRGUM HYDROXIDE
Tuesday, May 24, 2016 by APY QUEEN

Chemistry
A saturated solution of lead ii trioxonitrte v was prepared at 22degree Celsius at 27cm3 of this solution required 46cm3 of NaCl solution containing 96gdm3 for complete precipitation. Find the solubility of the lead in trioxonitrte v at 22degree Celsius in (a) mol/dm3 (b) g/dm3.
Tuesday, May 24, 2016 by Mohammed

chemistry
What is the specific heat capacity of a metal if it requires 175.0 J to change the temperature of 15.0 g of the metal from 25.00°C to 35.00°C? 1.17 J/g°C 11.7 J/g°C .875 J/g°C 325 J/g°C 17.5 J/g°C
Tuesday, May 24, 2016 by Ha

chemistry
A is a solution of trioxonitrate(v) acid, HNO3, of unknown concentration. B is standard solution of sodium hydroxide containing 4.00g per dm3 of solution. 25cm3 portions solution B required an average of 24.00cm3 of solution A for neutralization, using 2drops of methyl orange...
Tuesday, May 24, 2016 by oward

chemistry
How much mole of dry hydrogen at NTP is liberated on heating 0.1 mole of Mg with excess of dilute HCl? Actually what is NTP? I know the balaned equation and 1mole Mg forms 1 mole H2 , then 0.1 mole forms 1/0.1 moles of H2? Plz help
Monday, May 23, 2016 by anu mol

Chemistry
Complete the following equations: 1. Benzene + hydrogen fluoride ----> 2. Propanoic acid + ethanol ----> 3. 3-pentanol --->(oxidized)
Monday, May 23, 2016 by Rose

Chemistry
Complete the following equations. Include names of all reactants and products A) CH3CH2CHCH - CH2+H2O --> | CH3 B) CH3CHC=CCH3 + H2 ---> | CH3
Monday, May 23, 2016 by Rose

Chemistry help asap
what two ingredients are used to prepare basic buffer solution??
Monday, May 23, 2016 by Naz

Chemistry
50 L of your 0.05M sodium. chloride solution, what volume of 1.25M solution would be necessary?
Monday, May 23, 2016 by Blake

Chemistry
Put the following in order, from the one with the greatest impact on reaction rate to the one with the least impact on reaction rate: temperature, amounts of reactant, and presence of catalyst.
Sunday, May 22, 2016 by Anonymous

Chemistry
Given 100 mL of pure water at 40C, what volume of a solution of hydrochloric acid, with a density of 1.175 g/mL and containing 34.4% HCI by weight, could be prepared?
Sunday, May 22, 2016 by Sidney

Chemistry
Ammonia gas is passed into water, yielding a solution of density of 0.93 g/mL and containing 18.6% NH3 by weight. What is the mass of NH3 per mL of solution.
Sunday, May 22, 2016 by Kelly

Chemistry
I posted this before and I know now to use P1T2=P2T1 but I was wondering what I would plug in as pressure and temp? just an example of one would be so great. In each of the four problem in this section, all gases are measured at the same temperature and pressure. 1) (a) What ...
Sunday, May 22, 2016 by Eve

Chemistry
The air in a cylinder of a diesel engine occupies 1.00 L at 30 degrees celsius and 1.00 atm. What is the pressure in the cylinder when the air is compressed to 0.0714 L (14:1 compression ratio) and heats to 480 degrees celsius? When the fuel explodes in the compression chamber...
Sunday, May 22, 2016 by Eve

Chemistry
How to convert 4.6-10.5 micrograms/dL to nmol/L? The answer is 59-135 nmol/L, but I have no idea how to set it up to get that answer.
Sunday, May 22, 2016 by Student

Chemistry
What mass of solid magnesium hydroxide is needed to neutralize .385 L of 2.5 M nitric acid?
Sunday, May 22, 2016 by Morgan

Chemistry
What is the concentration of 127 mL of solution made with .450 g of nickel (II) nitrate hexahydrate?
Sunday, May 22, 2016 by Morgan

Chemistry
A sample of impure Limestone weighing 0.3440 g was treated with 50 mL of HCl 0.1363 mol/l. after elimination of all CO2 by boiling, excess acid was created by 4.45 mL of NaOH 0.1445 mol/L1. Calculate the% (w/w) of CaO and CaCO3 in the sample
Saturday, May 21, 2016 by Kelly

Chemistry
5 grams of H2 reacts with 16 g of O2, which in excess? 2H2(g)+O2(g)=2H2O(g)
Saturday, May 21, 2016 by Alan

chemistry
As when forming a hydroxide the ion OH is used in this manner Metal(OH)valence of metal does that mean that if my valence is 2 as with calcium,i have 2 molecules of oxygen and two of hydrogen??
Saturday, May 21, 2016 by Camila

chemistry
Name the product obtained on passing carbon iv oxide into saturated sodium trioxocarbonate (iv) solution
Saturday, May 21, 2016 by Tobasco

Chemistry
How can I make 100ml 0f 2N of HCl? purity is 35% and density is given as 1.18 g/mL
Saturday, May 21, 2016 by Anna

Chemistry
A sample of hydrogen gas (H2) is produced in a laboratory by displacement of water. A 645 mL sample of hydrogen is collected at 25 degrees Celsius and a total pressure of 758 torr. Collecting gas by water displacement causes the gas to become saturated with gaseous water vapor...
Friday, May 20, 2016 by Roger

Chemistry
Ok so I realize this is a lot of questions, but if someone could at least just give me the general set up for each problem that would save my life! In each of the four problem in this section, all gases are measured at the same temperature and pressure. 1) (a) What volume of ...
Friday, May 20, 2016 by Eve

Chemistry
Compute the approximate density of methane, CH4, at 20oC and 5.00 atm. The molecular weight of methane is 16.0.
Friday, May 20, 2016 by Eve

General Chemistry
Ferric Hydroxide, Fe(OH)3, is an insoluble salt with a solubility of 10^-39. 1) What is the maximum concentration of ferric hydroxide that can dissolve? 2) Using Le Chatalier's Principle, explain why iron (III) solutions are more soluble in acidic solution.
Friday, May 20, 2016 by Henry

Organic Chemistry
What volumes of 0.00250M salicylic acid solution and 0.1M ferric chloride solution would you need to make 50mL of a 0.00350M solution?
Friday, May 20, 2016 by Mike

Chemistry
Write the equation for the reaction of calcium and oxygen. Write the oxidation numbers for both the reactants and the products. What is the reducing agent and why?
Friday, May 20, 2016 by Carmen

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
Friday, May 20, 2016 by Kayla

Chemistry
Which atom has a change in oxidation number of –3 in the following redox reaction? K2Cr2O7 + H2O + S - - > KOH + Cr2O3 + SO2 K Cr*** O S
Friday, May 20, 2016 by Kayla

science(chemistry)
How is ethanol after 1 minutes of evaporation
Friday, May 20, 2016 by Anonymous

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. If the addition of 10.0 mL of a NaIO3 solution to the Cr (III) ion solution causes precipitation to begin, what is ...
Thursday, May 19, 2016 by MC

Chemistry
Fe+o2+h2o->fe(oh)3
Thursday, May 19, 2016 by Anu

Chemistry
What is the oxidation number for each atom in NH4F? N=+3, H=-4, F=+1 N=-3, H=+1, F=-1*** N=+3, H+1, F=-1 N=-3, H=-1, F=+1
Thursday, May 19, 2016 by Holly

Chemistry
Calculate H2 Equation 1- CH4g+2O2g+CO2g+2H2OgH1=-890kj Equation 2- CH4g+O2g+CH2Og+H2OgH2=? Equation 3- CH2Og++O2g+CO2g+H20gH3=-518kj
Thursday, May 19, 2016 by Sarah

Chemistry
Equation 1- 2Ss+3O2g+2SO3gh1=? Equation 2- 2Ss+2O2g+2SO2gh3=-594kj Equation 3- 2SO2g+O2g+2SO3gh3=-198kj Use Hess's law in your own words.
Thursday, May 19, 2016 by Sarah

Chemistry
What is the reducing agent in the following reaction? 2K + S - - > K2S K S*** K2S None of the above
Thursday, May 19, 2016 by Holly

Chemistry
Consider this reaction N2g+O2g+2NOg H=180.5kj How much heat would be required to produce 1.300 mol NOg?
Thursday, May 19, 2016 by Sarah

Chemistry
In the reaction of beryllium with fluorine, which atom is oxidized? fluorine beryllium*** neither of them both of them
Thursday, May 19, 2016 by Holly

Chemistry
What are transferred in an oxidation-reduction reaction? atoms*** electrons ions protons
Thursday, May 19, 2016 by Holly

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Homework Help: Science