CHEM !(MOLE) PLZ HELP!

13,097 results

chem

stilll didn't get it .. .. can u plz explain in detail ... how did u get the answer.. plz plz plz plz plzp l zp thnks Bond enthalpy is the energy required to break a mole of a certain type of bond. O=O = 495 kj/mol S-F = 327 kj/mol S=O = 523 kj/mol Use average bond enthalpies ...

Urgent Chem help plz

is answer +103 KJ.. plz chk Plz explain in detail.... i tried to search on internet but i am confused with co-efficents.. how to set up the equaiton .. plz help me ??? Bond enthalpy is the energy required to break a mole of a certain type of bond. O=O = 495 kj/mol S-F = 327 kj...

CHEM !(MOLE) PLZ HELP!

1.How many grams are in one mole silicon? 2. how many moles are in 128 grams of oxygen gas (O2)? 3.How many molecules are in 2 moles of AIO? 4.How many moles are in 18.06 x 10 to the 23 power? 5. how many moles are in 100 grams of CH4?

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

Urgent Chem Help someone plz

Calculate the mole fraction of the solute in the following aqueous solutions 3.25% ethanol, by volume (d= 0.993 g/ml ; pure C2H5OH, d= 0.789 g/ml )

gen chem

What is the ph of a soulution made by adding 0.20 mole NH3(aq) to 0.30 mole NH4Cl and 0.10 mole KOH to 100ml of water? Kb for NH3 (aq)=1.8x10^-5M

Chemisty (please read soon)

which will become a buffer in 1L of H2O? a) 0.3 mole KOH & 0.3 mole HBr b) 0.5 mole NH3 & 0.5 mole HCl c) 0.2 mole NaCl & 0.3 mole HCl d) 0.2 mole NaOH & 0.2 mole HBr e) 0.4 mole HC2H3O2 & 0.2 mole NaOH I think that the answer is e. Is that correct?

Chem Urgent Help

Plz explain in detail.... i tried to search on internet but i am confused with co-efficents.. how to set up the equaiton .. plz help me ??? Bond enthalpy is the energy required to break a mole of a certain type of bond. O=O = 495 kj/mol S-F = 327 kj/mol S=O = 523 kj/mol Use ...

Chem

At a particular temperature, Kc = 54 for the reaction If 1.0 mole of H2 and 1.0 mole of I2 are placed in a 5.0 L container, what would be the equilibrium concentration of HI?

Chemistry

Determine the simplest formula for compounds that have the following analyses. The data may not be exact. A. 28.5% iron, 48.6% O, 22.9% S This is what I did: 28.5g Fe 1 mole Fe/55.847g = .51 mole 48.6g O 1 mole O/15.999g = 3.04 mole 22.9g S 1 mole S/32.064g = .71 mole (Fe1.0 ...

Chem

Could you please tell me if these are right? How many moles are in the following. A.) 80.0 g of NaOH I got 2.0 moles. B.) 12.0 g of Ca(OH)2 I got 0.16 moles. Write the simplest formula for each of the following compounds. A.) 0.200 mole Al and 0.600 Cl. I got AlCl3 B.) 0.080 ...

Chem- PLZ HELP!

Consider 100g of 5.5% (mass) solution of NaNO3. Complete the following table, before calculating molarity, molality and mole fraction of NaNO3. Solute(NaNO3)|Solvent(H2O|Soln Mass(g) 100g Moles ---- RefInfo 85g/mol 18.02g/mol Density=1.00g/mol (This goes under "soln" as ...

chem

One mole of H2O(g) at 1.00 atm and 100.°C occupies a volume of 30.6 L. When one mole of H2O(g) is condensed to one mole of H2O(l) at 1.00 atm and 100.°C, 40.66 kJ of heat is released. If the density of H2O(l) at this temperature and pressure is 0.996 g/cm3, calculate E for ...

gen chem

What is the boiling point in K of Zn, if the entropy change for evaporation of .8564 mole at its boiling ponit is 95.067K? The heat of vaporization of Zn is 131jk/mole.

Chemistry

1 mole of equimolar mixture of ferric oxalate and ferrous oxalate will require xmole of KMnO4 in acidic medium for complete oxidation, x isis: a) 0.5 mole b) 0.9 mole c) 1.2 mole d) 4.5 mole

LIVING ENVIRONMENT

the ability to grow in size is a characteristic of living organism .Although an icicle may grow in size over time,it is considered nonliving because there is 1)an incerase in matter ,but no increase in the number of icicle. 2)an interaction between the icicle and the ...

chemistry

SHOW WORK How many moles of helium occupy 26.4 L at a pressure of 103.0 kPa, and 10 degrees Celsius? A.) 0.03 mole B.) 0.86 mole C.) 1.16 mole D.) 32.72 mole

Chem II

A 0.10 M HF solution is 8.4% ionized. Calculate the H^+ ion concentration. Here is my line of thought. For every mole HF disolved yeilds one mole of H^+. Since there is ).10 M HF, and the solution is 8.4% ionized = 0.84 M. Is this correct?

math

identify the value of x that makes each pair of the ratios equivalent x:4 and 45:20 A.8 B.9 C.10 plz plz plz plz help me!!!!!!!! PLZ!!!!!

college chem

Calculate the molar enthalpy of reaction standard enthalpy of formation below. H20 = -285.8 kj/mole H+ = 0.0 kj/mole OH- = -229.9 kj/mol H+(aq) + OH-(aq)→H2O(l) For this, don't you do the summation of products x stoichemtry + the sum of reactants x stoich. from there I'm...

chemistry

Determine the theoretical yield of C when each of the following amounts of A and B are allowed to react in the generic reaction: A+2B-->3C 1) 1mol A; 1 mole B 2) 1mole A; 3 mole B 3) 2mole A; 2 mole B 4) 32mole A; 68 mole B

chemistry

given the reactant amounts specified in each chemical eguation, determine the limiting reactant in each case: a. HCL+NaOH->NaCl+H2O 2.0 mole of HCl 2.5 mole NaOH b. Zn+2HCl->ZnCl2+H2 2.5 mole Zn 6.o mole HCl c. 2Fe(OH)3+3H2SO4->Fe2(SO4)3+6H2O 4.0 mole Fe(OH)3 6.5 mole...

chemistry

What is the mass of 4.80 moles of MgCl2?My answer is: Mg=24.3 g/mole Cl2=35.5g/mole*2=71g/mole so, Mg 24.3+ Cl2 71= 95.3g/mole therefore 4.80 moles * 95.3 g/mole=471.84g Am i right pls correct me if i'm wrong thanks

chemistry

For a given reaction, the rate constant doubles when the temperature is increasd from 27C to 49C What ite activation energy? Explain. a).347 KJ/mole b)25.5 KJ/mole c)31.5 KJ/mole d)52.7 KJ/mole

General Chem

Nitrogen oxide reacts with oxygen gas to form nitrogen dioxide (NO2). In one experiment 0.866 mole of NO is mixed with 0.503 mole of O2. Calculate the number of moles of NO2 produced

Chem II

A 0.10 M HF solution is 8.4% ionized. Calculate the H^+ ion concentration. The "8.4% ionized" is throwing me. This is my line of thinking. For every mole HF disolved yeilds one mole of H^+. Since there is 0.10 M HF and the solution is 8.4% ionized = 0.84 M. Is this correct?

CHEM

When 0.5 mole of CO2 and 0.5 mole of H2 were forced into a litre reaction container, and equilibrium was established: CO2(g) + H2(g) <--> H2O (g) + CO (g) Under the conditions of the experiment, K=2.00 a) Find the equilibrium concentration of each reactant and product. K...

I NEED HELP!!:(!!!! HELP ME PLZ!!

I GOT A FEW QUESTIONS SO what is a cell part that has the funcion of a gel-like material inside cells... and what releases energy into the cell.?? plz plz plz plz HELP!!!

math plz plz plz plz help plz .....thank you

mark bought a notebook for $1.45 and some pencils that cost $0.42 each if the total cost was 6.91,how many pencils did he buy A.12 B.13 C.14 D.15 is 14 the answer plz help thank you

Chem

When doing a limiting reagant problem, I need to determine to mole ratio, right? But the problem is if 19.6 g of H3PO4 reacted with 22.4 g KOH... How do I get two separate mole ratios? The answers are: 3/1 for H3PO4 and 3/3 for KOH, but why?

chem

a.)How many moles of NaOH are required to prepare 2.00L od 0.380M solution? answer is 0.760 mole of NaOH (mole/l * 2.00L) b.)What will be the molarity of a solution if 3.50 g of KOH are dissolved in water to make 150.0 mL of solution? answer is 0.52 M KOH (gKOH/molar mass KOH=...

Chemistry+empirical formula

What is the empirical forumla (lowest whole ratio) of the compounds below? A. 13.0g Mg 1 mole/24.312 = .53 mole 87.0g Br 1 mole/79.909g = 1.09 mole Mg .53/.53 Br 1.09/.53 Mg 1.0 Br 2.1 What do i do now?

Chemistry

I don't know how to start this problem. Someone can help me please. One dm3 of a solution was prepared containing 0.0040 mole of Pb(NO3)2. The Ksp of PbCI2 for the existing conditions is 2.4 x 10^-4. From the list below, choose the smallest numbers of NH4CI that when added to ...

Chemistry

8 g of sulphur is burnt to form SO2 which is oxidized by Cl2 water The solution is treated with BaCl2 solution The amount of BaSO4 precipitated is A/ I mole B/ 0.5 mole C/ 0.24 mole D/. 0.25 mole Which option is correct??

chemistry

Which of the following solutes dissolved in 1000 g of water would provide a solution with the LOWEST freezing point? A. 0.030 mole urea, CO(NH2)2 B. 0.030 mole acetic acid, CH3COOH C. 0.030 mole ammonium nitrate, NH4NO3 D. 0.030 mole calcium sulfate, CaSO4 E. 0.030 mole barium...

social studies? i think idk

what new ideas came from the automobile? plz help plz plz plz ASAP

Math ....urgent help

i just don't get this elimination method ..... plz help me plz.....teach me how to keep the x and y in a parallel line. and which number to multiply.....plz help -5x-4y=-11 10x=-6-y help me plz......

SS plz help me plzzzzzzz

What are the two major forces that reshape earth? Describe how itworks. plz plz plz help me there are no answer choices hope u can still help

SS PLZ HELP ME ASAP

What are the two major forces that shape and reshape earth? Describe how each one works. plz plz plz help me there are no answer choices hope u can still help

Chem 112

Calculate the pH of a buffer solution prepared by dissolving 0.12 mole of cyanic acid, HCNO and 0.65 mole of sodium cyanate, NaCNO in enough water to make 1.0 liter of solution. [Ka(HCNO) = 2.0 × 10-4] I know that this question has something to do with turning moles into ...

chem

calculate the change in enthalpy when 1.00g of hydrogen peroxide decomposes. H2O2(l) yields H2O(l)+ 1/2O2(g) (traingle)H- -98.2kj I will be happy to critique your thinking on this. help me? You know the delta H is for one mole decomposition. So figure the fraction of 1gram/one...

ap chem

how do you find mole fraction?

gen chem

A sample of glucose C6H12O6 contains 2.03x10^21 atoms of carbon. how many atoms of hydrogen does it contain? mole of H= 6.02x10^23/2.03x10^21? i don't know if my formula is right and i also don't know where to get the mole of H. please help me understand this problem how many ...

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

How many moles of Sulfur are in 1 mole of Al2(SO4)3 and If the densitry of a noble gas is 1.783 g/L at STP, that gas is.... My guess: Argon? Then theres a question that says "Which as the greater mole.... and it lists things like: 1 mole Of Ar 1 Mole of O How would you figure ...

biology

a boy inherits genes for tallness,but his growth is limited as a result of poor nitrition. this is an example of 1)an inherited disorder. 2)environmental influence on gene expression . 3)expression of a hidden trait 4)a characterstic controlled by more than one pair of genes. ...

Chemistry

7.5 L of hydrogen gas at STP and zinc (II) nitrate was produced by reacting zinc with nitric acid. Calculate the mass of zinc needed for this reaction. This is what I did: Zn + 2HNO3 = H2 + Zn(NO3)2. 7.5L H2 * 1 mole H2/ 22.4 L H2 * 1 mole Zn/ 1 mole H2 * 65.4 g Zn / 1 mole Zn...

Ap Chem

If in an experiment we're working with Mg, HCl acid, and H20. We stick the magnesium in the acid mixed with water and the Mg dissolves. One of the products is hydrogen gas. If the water in the tube is evaporated, the other product, a white salt remains. Write a balanced ...

Chemistry

According to the balanced equation 6 moles of carbon dioxide will react with 6 moles of water to produce 1 mole of sugar and 6 moles of oxygen. What are the molar masses of the following compounds from the photosynthesis equation? CO2=___________g=1 mole H20=___________g=1 ...

chemistry needs another look plz

Posted by Lori on Tuesday, December 14, 2010 at 5:38pm. The mole fraction of an aqueous solution of potassium perchlorate is 0.125. Assuming that the density of this solution is 1.20g mL-1, calculate the following: (A) the mass percent of potassium perchlorate in the solution...

Chem

Which of the following are correct statements? (Could be as many as 4) 1. One mole of gas contains 22.4 representative particles 2. Standard pressure is 100 mm Hg 3. One mole of a gas must have the same volume as one mole of any other gas at STP 4. Gas molecules are spaced far...

Chemistry

0.05 mole of HCL is added to a liter of buffer containing 0.04 mole of NH3 and 0.03 mole of NH4CL. What is the ph? Kb= 1.8X10^-5

chemistry

if .5 mole of baCl2 is mixed with .2 mole of Na3Po4.Then maximum number of mole of Ba3(PO4)2 is

chem

how many atoms are there in 0.0300 mole of methane molecules?

chem

0.210 mole of Na2CO3 in 200.0 mL of solution

Chem II

PCl5 dissociates according to the reaction: PCl5(g) ↔ PCl3(g) + Cl2(g). One mole of PCl5 was placed in one liter of solution. When equilibrium was established, 0.5 mole of PCl5 remained in the mixture. What is the equilibrium constant for this reaction?

plz plz help me belive me have tried

cosx+cosy=a and sinx+siny=b show that sin2x+sin2y=2ab(1-(2/(a^2+b^2)) plz plz show step

chemistry

A closed gas cylinder contains 0.500 mole H2, 0.300 mole O2, 1.200 mole CO2 at a temperature of 25 °C and a pressure of 2.00 atm

CHEM HELP

what is the theoretical mole ratio- NaCl to NaHCO3 How do you determine the percentage error of an experimental mole ratio It would be easier for us to help you if we had the entire problem instead of just parts of it. However, from the standpoint of Na, the mole ratio of NaCl...

CHEM

For a crystal with formula BaCl2.xH2O, a student conducted a gravity experiment and found out that 2.44 gram of this crystal can lost mass 0.36 gram when heated to 150 degree. Suppose water is the only reason of weight loss, what is the x value here? (Molar mass of BaCl2 is ...

chem

what is the energy of a mole of UV photons having a wavelength of 13nm?

Plz someone Chem Urgent Help

The overall energy involved in the formation of CsCl from Cs(s) and Cl2 (g)is - 443 kj/mol. Given the following information: •heat of sublimation for Cs is +76 kj/mol, •bond dissociation energy for ½ Cl2is +121 kj/mol, •E(11) for Cs is +376 kj/mol, and •E(a) for Cl2is...

STATS/CHEM

I get how to use the method of least squares to determine slope, intercept, uncertainties in slope and intercept of your graph and but am confused how to determine the error of mole percent stated in (ii) The following are peak areas for chromatograms of isooctane standards ...

chem

Zinc dissolves in acid according to the balanced equation. Zn(s)+ 2H(aq)-> Zn(aq) + H2(g) a sample of zinc is placed in a ice calorimeter. If 0.0657g of zinc causes a decrease of 0.109ml in the ice/water volume of the calorimeter, what is the enthalpy change, per mole of ...

chem

Zinc dissolves in acid according to the balanced equation. Zn(s)+ 2H(aq)-> Zn(aq) + H2(g) a sample of zinc is placed in a ice calorimeter. If 0.0657g of zinc causes a decrease of 0.109ml in the ice/water volume of the calorimeter, what is the enthalpy change, per mole of ...

Chem history

Why was carbon chosen over silicon in defining the mole?

chem

One mole of pentanol (C5H11OH) contains how many hydrogen (H) atoms?

chem

mole fraction of CHOHCH in H2O calculate molality of solution

Organic Chem/ Calculate Yield

How would you calculate the percent yield for a reaction that began with 10 moles of acetone and 16 moles of benzaldehyde which yielded 6 moles of dibenzalacetone as the product? The molecular weights are as follows (acetone = 58.08 g/mole), (benzaldehyde = 106.2 g/mole), (...

chem please help

In the reaction AgNO3(aq) + HCl(aq) AgCl(s) + HNO3(aq) + heat, when 0.70 mole of AgNO3 and 0.70 mole of HCl react, the temperature of 50 g of water increases from 15°C to 30°C. If the specific heat of water is 4.18 J/g•°C, how much energy was produced in the AgNO3 ...

chemistry(please check my work)

If 0.836 g of solid Al reacts stoichiometrically according to the balanced equation in a reaction solution with a total volume of 1160 mL, what mass (g) of gaseous H2 is produced? 6 HClO4(aq) + 2 Al(s) → 3 H2(g) + 2 Al(ClO4)3(aq) 0.836g/molecular weight Al=mole of Al ...

Geometry i need help urgently plz plz plz

The lenght of a line segement is of 10units and the co-ordinate of one end point are (2,-3) if the abscissa of the other end is 10 find the ordinate of the other end?? Working plz plz

Science

If 1 mole of acetic acid and 1 mole of ethyl alcohol are mixed and reaction proceeds to equilibrium, the concentration of acetic acid and water are found 1/3 and 2/3 mole respectively. If 1 mole of ethyl acetate and 3 mole of water are mixed,how much ester is present when ...

college chem

Calculate the Mole Fraction of benzene in toluene if there are 5 grams of each in the mixture

chem

Im not sure how to go about this: Calculate the number of gramms in 0.65 mole of aluminum carbonate?

chem

Im not sure how to go about this: Calculate the number of gramms in 0.65 mole of aluminum carbonate?

chem

what is the relationship between the amount of heat produced per mole of reactant?

chem

what is the relationship between the amount of heat produced per mole of reactant?

Chem

how many grams of KMnO4 should be weighed out to give 0.100 mole?

calculus help me plz too hard show step

charge Q coulombs at time t seconds is given by the differential equation RdQ/dt+Q/C=0, where c is the capacitance in farafd and R the resistance in ohms.solve the equation for Q given that Q=Qo where t=0 plz show step plz plz plz

AP Chem

What energy change is associated with the reaction to obtain one mole of H2 from one mole of water vapor? The balanced equation is 2 H2O(g) -> 2 H2(g) + O2(g)and the relevant bond energies are H-H : 436 kJ/mol; H-O : 467 kJ/mol; O-O : 146 kJ/mol; O=O : 498 kJ/mol. 1. +249 ...

AP Chem

What energy change is associated with the reaction to obtain one mole of H2 from one mole of water vapor? The balanced equation is 2 H2O(g) -> 2 H2(g) + O2(g)and the relevant bond energies are H-H : 436 kJ/mol; H-O : 467 kJ/mol; O-O : 146 kJ/mol; O=O : 498 kJ/mol. 1. +249 ...

Science/Chem

How many representative particles are in 2.5 mol H2O2? each mole consists of 6.02*10^23 things. Memorize that.

chem

why we have to normalize the proton NMR areas to determine the mole % oa a compound in a mixture?

chem

how many moles of water are present in one mole of zinc sulphate and write the formula for this?

chem

how does the tepmperature , pressure and mole parameter explain the suddden collapse of the can in imploding the can experiment?

Chemistry

Is this true or false? Thanks A mole of CCl4 is composed of one atom of carbon and four atoms of chlorine. I put false because it contain one mole of C 4 mole of Cl. Each mole have more than one atoms. Thanks

Chem

A solution of lithium chloride in water has a mole fraction of 0.0500 in LiCl. What is the molality? Mole fraction = moles of LiCl over total moles of solution Molality=moles of LiCl per kg of solvent How do I link this information?

CHEMISTRY

what is the symbol for chromium (II) sulfate? You mean the formula? CrSO4 yes! thanx!!!!!! do u know how to find the number of molecules or atoms in a mole? The number of atoms in a mole is called Avogadro's number, the value of which is approximately 6.02 × 10^23. There are ...

Chem

Calculate the absolute error in a mole ratio. Determine mole ratio of Zinc iodide. error in mass (g) was +- 0.005 Mass of reacted Zn = 0.16 Mass of iodine = 1.134 experiment value= 1:1.95 calculate absolute error in 1.95?

chemistry

for this question How many liters of H2 gas at STP are produced when Zn reacts with 125 mL of 6.00 M HCl? my book answers it this way: 0.125 L x 6.00 mole HCl x 1 mole H2 x 22.4 L 1 L 2 mole HCl 1 mole = 8.40 L of H2 gas where did the 22.4L come from?

math

the volume of a rectangular solid is given by expressions given below.in each case find the dimentions of the solid. a)15x^2-51x+18. b)x^3+13x^2+32x+20. c)x^2-5x/2-3/2. d)x^4+x^3-x-1 plz everyone help me out.till 2 o'clock...plz plz plz

math

the volume of a rectangular solid is given by expressions given below.in each case find the dimentions of the solid. a)15x^2-51x+18. b)x^3+13x^2+32x+20. c)x^2-5x/2-3/2. d)x^4+x^3-x-1 plz everyone help me out.till 2 o'clock...plz plz plz

CHEM!!

One mole of NH3 was injected into a 1 L flask at a certain temperature. The equilibrium mixture

Chem

At a particular temperature, Kc = 54 for the reaction H2(g) + I2 (g) <=> 2 HI(g). One mole of HI is placed in a 3.0-L container. What would be the equilibrium concentration of HI?

college chem

How many moles of O are needed to combine with 0.223 mole of C to form the following compounds? CO CO2

Chem 2

left a line out of answer 1.546x10-2mols CuSO4x2=3.09x10-2 mole ions

Chemistry

At the start of the reaction there are 0.714 mole of H2, 0.984 mole of I2, and 0.886 mole of HI in a 2.70 L reaction chamber. Calculate the concentrations of the gases at equilibrium.

chem

What is the pH of a 0.36 M HCl solution? can someone help plz? I don't know how to go about figuring this out.

p chem

1/2 mole CCl4 @ 25 C was mixed with 1/2 mole CH2Cl2 @ 25C. The final T was 27 C. Calculate delta S mixing, delta S for CCl4 on heating, delta S for CH2Cl2 on heating, and delta S system. Assume 131.8 J/K for Cp for CCl4 and 100.0 J/K for Cp for CH2Cl2.

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