# Calculate the enthalpy change (delta H...

37,968 results, page 5

### chemistry

Consider the following reaction. CH4(g) + 2 O2(g) CO2(g) + 2 H2O(l) ÄH = -891 kJ Calculate the enthalpy change for each of the following cases. (a) 5.00 g methane is burned in excess oxygen.

### Chemistry

ZN(s) + 2H+(aq) produces ZN2+(aq) +H2(g) A sample of Zinc is placed in the 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 Zinc, for the above reaction per mole of zinc. ...

### Chemistry

When atmospheric pressure is 700. mmHg, water boils at 97.714 degrees C. Calculate entropy change of water if 50.0 grams is vaporized under these conditions. The heat of vaporization of water can be found in almost any reference text, and Cp H2O= 33.6 J/molK. I found the heat ...

### Thermochemistry

The enthalpy formation of ethanol, C2H5OH, is -277.0 kJ/mol @ 298.15 K. Calculate the enthalpy of combustion of one mole of ethanol, assuming that the products are CO2(g) & H2O (l).

### chemistry

2. Methanol, CH3OH, is used as fuel in race cars. This liquid fuel can be synthesized using the following process C(s)+ ½ O2(g) + 2H2(g)  CH3OH(l) Calculate delta G using the deta Gf of the reaction. Calculate Kp. What is the relation between the magnitude of delta G ...

### Chem 2

for the evaporation of water during perspiration on a hot dry day 1.delta H is greater than zero and Tdelta S is equal to Delta H 2.delta H is greater than zero and Tdelta S is gretaer than Delta H 3.delta H is greater than zero and Tdelta S is less than Delta H 4.delta H is ...

### Chemistry

The net reaction in a voltaic cell with Eºcell= +.726V 2Fe^3+(aq) + 3Zn(s) --> 2Fe(s) + 3Zn^2+(aq) What is the delta Gº for this reaction at 25ºC I tries using this equation: delta G = -nFEºcell = -n(90485)(.726) However, I don't know how to calculate n in this. I ...

### Chemistry

Hydrogen peroxide, H2O2, is a colorless liquid whose solutions are used as a bleach and an antiseptic. H2O2 can be prepared in a process whose overall change is the following. H2(g) + O2(g) H2O2(l) Calculate the enthalpy change using the following data. H2O2(l) H2O(l) + 1/2 O2...

### chemistry

Q1) For the reaction, A to B, Delta H= +11.00 kJ mol-1 and Keq is 12.50 Calculate i) delta G and ii) delta S at 25 C (degrees celcius) 0 C degrees celcius = 273.15 K; R = 8.314 J K-1 mol-1]

### ap chem

calculate the lattice enthalpy of potassium fluoride from the following data: enthalpy of formation of K(g): +89 kJ · mol−1 first ionization energy of K(g): +418 kJ · mol−1 enthalpy of formation of F(g): +79 kJ · mol−1 electron affinity of F(g): +328 (H...

### Chemistry

2)Which of the following equations represents a reaction for which the delta H can be called a standard enthalpy of formation, delta Hf? a) FeO(s) + CO2(g) -> FeCO3(s) b) 1/2 N2(g) + 2 O(g) -> NO2(g) c) 2 Na(s) + Cl2(g) -> 2 NaCl(s) d) Ba(s) + N2(g) + 3 O2(g) -> Ba...

### chemistry

Calculate the value of DHo for the reaction 2 CH4 (g) -> C2H6 (g) + H2 (g) given the following thermochemical equations: C2H2 (g) + H2 (g) -> C2H4 (g) delta = – 175.1 kJ C2H6 (g) -> C2H4 (g) + H2 (g) Delta = + 136.4 kJ C2H2 (g) + 3 H2 (g) -> 2 CH4 (g) Delta...

### Chemistry

delta T = ikfm delta T is the amount f.p. is lowered. i is the number of particles; i.e., Na3PO4 will have i = 4 (3 for Na and 1 for PO4). m is molality. k is a constant and need not enter into the calculations. Arrange the following solutions in order of decreasing freezing ...

### chemistry

CaCO2--> CaO+CO2 <-- Calculate the pressure of CO2 in an equilibrium process at (a)22 Celsius and (b) 755 Celsius . Assume delta H=177.8KJ/mol and delta S=160.5 J/mol*K for that temeprature range. My question is do I have to subtract the two temperatures since it says "...

### Chemistry

I'm trying to write a sentence like this: Exothermic reactions have a negative enthalpy change value because the enthalpy of the reactants are greater than the enthalpy of the products since the reactants have weaker bonds.... Why do weaker bonds have higher energy/enthalpy? I...

### Chemistry

Hydrogen peroxide is used as a bleachin agent, a disinfectant and medicinally as a topical antibacterial agent. Hydrogen peroxide decomposes according to the reacton 2H^2O^2(l)-->2H^2O(l)+o^2(g) A. Given the standard free energy of formation values shown below, calculate ...

### Chemistry

Is the following reaction spontaneous at 25*C? delta s reaction = -217 J/K*mol delta H rxn = -1202 KJ 2Mg (s) + O2 (g) -> 2MgO (s) delta suniverse = delta s system - delta H system / T i got positive (+) 3.81 x 10 ^ 3 J/K and my notes says it is spontaneous but i feel like ...

### Chemistry

Consider the following data: * NH3(g) yields 1/2 N2(g) + 3/2 H2(g) delta H = 46kJ * 2 H2(g) + O2(g) yields 2 H2o(g) delta H = -484 kJ Calculate delta H for the reaction: 2 N2(g) + 6 H2O (g) yields 3 O2(g) + 4 NH3(g)

### chemistry

use the following data, as appropriate, to estimate the molarity of a saturated aqueous solution of Sr(IO3)2. Molarity of a saturated aqueous solution of Sr(IO3)2 Sr(IO3)2(s) delt h kJ/mol=-1019.2 delta G kJ/mol=-855.1 delta S= 234 J mol-1K-1 Sr^2+(aq) delta h= -545.8 kJ/mol ...

### chemistry

use the following data, as appropriate, to estimate the molarity of a saturated aqueous solution of Sr(IO3)2. Molarity of a saturated aqueous solution of Sr(IO3)2 Sr(IO3)2(s) delt h kJ/mol=-1019.2 delta G kJ/mol=-855.1 delta S= 234 J mol-1K-1 Sr^2+(aq) delta h= -545.8 kJ/mol ...

### thermodynamics

find change in enthalpy and change in entropy when liquid water at 30¡ãc is converted to steam at 40 bar,375¡ãc.

Find the following limit where f(x) = 4x^2 − 3x. limit-->(f(x+ delta x)-f(x))/(delta x) delta x **delta x means the triangle symbol with x next to it***

### Physics

this question came up in my work, and i don't remember reading about it in my book. can you tell me what it is asking for, and how to do it.. if the change in position delta x is related to velocity v(with units of m/s) in the equation delta x=Av, the constant A has which ...

### Chemistry 152

For a certain reaction, the enthalpy change is -148.5 kJ, the entropy change is 256 J/K, and the free energy change is -250.1 kJ. At what temperature is the reaction occurring, in C? Choose one answer. a. 85 b. 102 c. 124 d. 158 e. 210

### Chem

How would one calculate change in enthalpy only knowing heat capacities of all substances involved/required? at a known T... WOuld you use a multi-stepped pathway and if so, how?

Calculate the minimum change in velocity (delta V or ∆V) required for the Space Shuttle to decrease its altitude to 60 miles if it’s orbiting with an apogee of 236 miles and a perigee of 215 miles above the surface of Earth. Use the rule of thumb that below an altitude...

### Chemistry

I did a lab today in class and part of the lab is to experimentally find the enthalpy for the dissolution of ammonium chloride by dissolving 4.0 g of NH4Cl(s) in 50.0 mL of H2O(l). I got a -5°C temperature change and calculated delta H to be 15 kJ/mol. According to the ...

### chemistry

Calculate te calue of Ksp for Ca(NO3)2 using the data below. Ba(aq) delta G0f= -561 kJ/mol NO3 (aq) delta G0f= -109 kJ/mol BaNO3 (s) delta G0f= -797 kJ/mol

### Chemistry

Determine the entropy change when 7.40 mol of HCl(l) boils at atmospheric pressure. I already have the delta Sfus(12.5 J/Kmol) and delta Svap(93.2 J/Kmol), I just cant seem to figure out the last part.

### chem

Consider the equation A <-> in a 1L container. At 7.57C, the molar concentrations of A and B are 7.228M and 1.976 (respectively). Suddenly, 1.831 moles of A are added to the system. What is the change in deltaG of the system (Answer in kJ) At first, I thought I would use...

### chemistry

Using data in table below and S °(C2H6(g))= 229.5 J·mol-1·K-1, calculate ÄfS° for C2H6(g) in J·mol-1·K-1. Compound S °, J·mol-1·K-1 Compound S °, J·mol-1·K-1 C(s) 5.69 H2(g) 130.6 I am sorry , last time i did not show my working. thanks for helping me . Delta S= ...

delta Go = -431.16kJ/mol - (298k X 0.12529 kJ/K*mol) I am having trouble converting the units for delta H and delta s to match. I multiplied delta H by 1000 to get kJ but this didn't give me the correct answer.

### chemistry

these are my three thermochemical equations 2Cu(s)+S(s) give Cu_2S(s) delta H -79.5 KJ S(s)+O_2 give SO_2(g) -297 KJ Cu_2S(s)+2O_2(g) give 2CuO(s)+SO_2(g) how i calculate standard enthalpy of formation in Kj per mol of CuO(s)? please don't give the answer only guid me please

### chemistry

Calculate the change in free energy when you drop 4.70 g of calcium metal into a beaker containing excess water so that Ca(OH)2(s) and H2 gas are formed? The delta-G values you need are in your textbook. The units are kJ.

### chemistry check

please check Write the balanced equation, with the enthalpy component, for the rusting process, given that Hf for iron and oxygen is 0 and Hf for ferric oxide is -826 kJ/mol. 4 Fe (s) + 3 O2 (g) --------> 2 Fe2O3 (s) You need to add the heat one of three ways. 4 Fe (s) + 3 ...

### chemistry

Exactly .203g of zinc metal is dissolved in dilute HCl(aq) in an ice calorimeter. The heat released melts enough ice to produce a volume change of 0.254mL in the ice water mixture surrounding the reaction vessel. Calculate the enthalpy change per mole of zinc for the reaction...

### Chemistry

consider the following reaction: 2CH3OH(g) yields 2CH4(g) + O2(g) change in enthalpy= 252.8kJ Calculate the amount of heat transferred when 26.0 g of {\rm CH_3OH} (g) is decomposed by this reaction at constant pressure.

### chemistry

From the following information, calculate the standard change of enthalpy for the combustion of coal. C + O2 -> CO2 COMPOUND HEAT OF FORMATION coal 0.0 carbon dioxide -393.5 water (l) -285.9 oxygen 0.0

### Chemistry

What is the enthalpy change for the first reaction? Fe2O3(s) → 2Fe(s) + 3/2O2(g) ΔH = 4Fe(s) + 3O2(g) → 2Fe2O3 (s) ΔH = -1,652 kJ I think I'm supposed to rearrange the equation and double everything but enthalpy isn't my strong suit

### Chemistry

Consider the following data. DeltaHf (Na2O (s))=-414kJ/mol Delta H sublimation(Na)=109 kJ/mol I.E. (Na)=495 kJ/mol Bond Energy (O2) = 495 kJ/mol E.A. (O) = -141 kJ/mol E.A. (O -) = 878 kJ/mol Use this information to calculate the lattice energy of Na2O (s). So, we have the ...

### Chemistry

I'm stuck...that is i believe I've come to an impossible answer: I need to calculate the equilibrium constant 4Fe(s) + 3O2(g) --> 2Fe2O3(s) First off: Delta G G Fe(s) = 0, G O2(g) = 0, G Fe2O3(s) = -741 (x2) -741 (2) - 0 = -1480 = delta G of reaction at equilibrium: 0 = (...

### Chemistry

I'm stuck...that is i believe I've come to an impossible answer: I need to calculate the equilibrium constant 4Fe(s) + 3O2(g) --> 2Fe2O3(s) First off: Delta G G Fe(s) = 0, G O2(g) = 0, G Fe2O3(s) = -741 (x2) -741 (2) - 0 = -1480 = delta G of reaction at equilibrium: 0 = (...

### general chemistry

A sample consisting of 0.025 mol of a solid compound is placed inside a metal cylinder. The cylinder was immersed in a water bath consisting of 10.00 kg of water at an original temperature of 25.00 °C. When the compound decomposes, the temperature of the water rises to 29.52...

### chemistry

a balloonist is preparing a trip in a helium balloon. the trip begins in early morning at a temp of 15 degrees Celcius. By mid afternoon, the temp has increased to 30 degrees C. assuming the pressure remains constant at 1.00 atm, for each mole of helium, calculate: 1. the ...

### New AP Chem Question for Dr. Bob

This is a Hess' Law problem. I think I got it but I'm hoping you could check it for me: Calculate the heat of reaction for changing 1 mol of silica, SiO2, that has been extracted from sand into the pure silicon that is needed to make computer chips. Use the following data: ...

### 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 ...

### chemistry

2CH3OH(l)+3O2(g)→2CO2(g)+4H2O(g Part B Calculate the standard enthalpy change for the combustion of 1 mol of liquid methanol, assuming H2O(g) as a product. Part C Calculate the heat produced by combustion per liter of methanol. Methanol has a density of 0.791 g/mL. Part ...

### chemistry

A scientist measures the standard enthalpy change for the following reaction to be -172.4 kJ : 2SO2(g) + O2(g) 2SO3(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of SO2(g) is what in kJ/mol?

### Chemistry

Consider a system consisting of 2moles CO2 gas initially at 25 deg and 10 atm and confined to a cylinder of cross section 10.0 square centimeter. lt is allowed to expand adiabatically against an external pressure of 1.0 atm until the piston has moved outwardsthrough 20cm. ...

### Chemistry

Can anyone help me with these three questions? Predict the sign of delta S° and then calculate delta S° for each of the following reactions a. 2H2S(g) + SO2(g) --> 3S(rhombic)(s) + 2H2O(g) b. 2SO3(g) --> 2SO2(g) +O2(g) c. Fe2O3(s) + 3H2(g) --> 2Fe(s) + 3H2O(g) Thank...

### pressure change

What is the pressure change for the reaction below at 25 C in the process of reaching equilibrium if there is initially enough ammonium hydrogen sulfide to reach equilibrium? Kp= 4.0*(10^4) NH3(g)+H2S(g) ---><--- NH4HS(s) Answer: 1.0*[10(-2)] Not sure what to do here; I ...

### Chemistry

Please help, I am having trouble solving these problems at nonstandard temperatures. Methanol burns in oxygen to form carbon dioxide and water. Using the balanced reaction, 2CH3OH(l) + 3OH2(g) --> 2CO2(g) + 4H2O(g) 1) Calculate delta H(rxn) in kJ at 24 degrees Celsius 2) ...

### Chemistry

Calculate the enthalpy change, ∆H in kJ, for the reaction H2O(s) → H2(g) + 1/2O2(g) Use the following: A. –291.9 kJ B. +291.9 kJ C. –279.9 k D. +279.9 kJ D??

### Chemistry

The reaction Fe + Br2 ---> FeBr2 Delta H = -249.8kJ Calculate delta H when 10.0 g of FeBr2 is formed.

### Chemistry

Consider the following reaction. CH4(g) + 2 O2(g) CO2(g) + 2 H2O(l) ÄH = -891 kJ Calculate the enthalpy change for each of the following cases. 1.00 103 L methane gas at 719 torr and 26°C is burned in excess oxygen.

### chemistry

A scientist measures the standard enthalpy change for the following reaction to be -2923.0 kJ : 2C2H6(g) + 7 O2(g) 4CO2(g) + 6 H2O(g) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of CO2(g) is _________

### Chemistry

When a chemist burns ammonia according to the reaction below she finds that the reaction releases heat. (It is exothermic.) 4NH3(g) + 3O2(g) 2N2(g) + 6H2O(g) The enthalpy of the reaction DH = -1267 kJ. What is the enthalpy change (in kJ) when 7 grams of ammonia are burned?

### chemistry 101

The enthalpy change was determined for the following reactions; Ca (s) + CO2 (g) + ½ O2 (g ) → CaCO3 (s) ΔH = -812.8 kJ/mo l Ca (s) + ½ O2 (g) → CaO (s) ΔH = -634.9 kJ/mo l What is the enthalpy change for the following reaction? CaCO3 (s) → CaO (s...

### chem

given the thermochemical equations, B2O3 + 3H2O -> 3O2 + B2H6 delta h = -2035 kj H2O -> H2O delta h = 44 kj H2 + 1/2O2 -> H2O delta h = -286 kj 2B + 3H2 -> B2H6 delta h = 36 kj what is the delta hf for 4B + 3O2 -> 2B2O3?

### chemistry

consider the following reaction at 298K 4Al(s)+3O2(g) yields 2Al2O3(s) delta H= -3351.4 Kj find delta S sys find delta S surr find delta S unvi

### Chemistry

consider the following reaction at 298K 4Al(s)+3O2(g) yields 2Al2O3(s) delta H= -3351.4 Kj find delta S sys find delta S surr find delta S unvi

### Chemistry

2CH3CH2CH2OH(l)+9O2(g)→6CO2(g)+8H2O(g) I have to find the delta G delta G of CH3CH2CH2OH(l)=−360.5 KJ/Mol delta G of O2(g)=0 KJ/Mol delta G of CO2(g)=−394.4 KJ/Mol delta G of H20(g)=−228.6 KJ/Mol I keep getting -3426.2 KJ/Mol but its not correct.

### Chemistry

The combustion of benzoic acid releases 26.38kJ/g and is often used to calibrate a bomb calorimete. The combustion of 1.045g of benzoic acid caused the temperature of the calorimeter to rise by 5.985 degreeC.Using the same calorimeter, a sample of 0.876g of C8H18 was burned. ...

### winterWx

A 0.30-kg softball has a velocity of 12 m/s at an angle of 30° below the horizontal just before making contact with the bat. What is the magnitude of the change in momentum of the ball while it is in contact with the bat if the ball leaves the bat with a velocity of 17 m/s, ...

### chemistry

For a certain reaction, Delta H(not) = -76.8 kj and delta S(not) = -217 j/k. If n =3, calculate E for the reaction at 25degrees celcius.

### chemistry

For a certain reaction, Delta H(not) = -76.8 kj and delta S(not) = -217 j/k. If n =3, calculate E for the reaction at 25degrees celcius.

### 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 ...

### chemistry

Equilibrium constant K for some reaction at temperature 300K was found to be 100 .Calculate equilibrium for same reaction at 400K if R= 8.23 change in enthalpy is 5000J

### chemistry

Delta H is given and is-6186.0 Calculate the difference, deltaH-deltaE=delta(PV) for the combustion reaction of 1 mole of methyl octane. (Assume standard state conditions and 298 K for all reactants and products.)

### Chemistry

Hydrogen and methanol (CH3OH) have both been proposed as alternatives to hydrocarbon fuels. a) Write balanced chemical equations for the complete combustion of hydrogen and the complete combustion of gaseous methanol. Combustion reaction for hydrogen: 2H2(g)+ O2 --> 2H2O(l...

### CHEMISTRY!! NEED IMMEDIATE HELP PLEASE!!!

a. Calculate the delta H, delta G, and equilibrium constant for the reaction of methane with Cl2 to give CH3Cl and HCl. Use the following information for your calculations: Bond Dissociation Energies: CH3-H (104.8kcal/mol), Cl-Cl(59.0 kcal/mol), CH3-Cl(85.0 kcal/mol), and H-Cl...

### chem!

i cant figure this one out! :( a balloonist is preparing a trip in a helium balloon. the trip begins in early morning at a temp of 15 degrees Celcius. By mid afternoon, the temp has increased to 30 degrees C. assuming the pressure remains constant at 1.00 atm, for each mole of...

### Analytical Chemistry

When BaCl2-H2O (s) is dried in an oven, it loses gaseious water: BaCl2-H2O <--> BaCl2(s) + H2O (g) enthalpy change - 63.11 kJ/mol at 25 degrees C entropy change - +148 J/(K-mol) at 25 degrees C Calculate the vapor pressure of gaseous H2O above BaCl2-H2O at 298K.

### Chemistry (How do I calculate)

Calculate the Molar Enthalpy of Neutralization (ΔHn) in kJ/mol of the reaction between a monoprotic acid and a monoprotic base, given the following information: The temperature change equals 6.92°C, 50.0 mL of 1.00 M concentration of Acid 50.0 mL of 1.00 M concentration ...

### chemistry

divide eq 2 by 2: 2H(g)........> H2(g) delta H= -104.2Kcal H(g) ........> 1/2 H2(g) delta H= -72.1Kcal Now reverse the reaction: 1/2H2(g).......>H(g) delta H=+72.1Kcal subtract this eq from eq 1 1/2H(g)+1/2I2(g).....>HI(g) delta H=-1.1kcal +-1/2H2(g)......>+-H(g...

### 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

I want to know the enthalpy change for this reaction which occurs in a blast furnace: Fe2O3(s) + 3C(s) --> 2Fe(l) + 3CO(g) You will need the heat of formation for CO, and ironIIIoxide, and the heatofmelting for iron. I suspect you have some temperature in mind also which ...

### Chemistry

i tried to do like dis plz chk is it rite or wrong. [2(4(327) + 495 ]- [ 2(4(327) + 523 ] = -28 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 to estimate the ...

### chemistry

From the following Information, calculate the standard change of enthalpy for the combustion of coal. SHOW WORK AND BALANCED REACTION!!! Compound DeltaHf (kj/mol) Coal 0.0 Carbon dioxide -393.5 Water (l) -285.9 Oxygen 0.0

### chemistry

From the following Information, calculate the standard change of enthalpy for the combustion of coal. SHOW WORK AND BALANCED REACTION!!! Compound DeltaHf (kj/mol) Coal 0.0 Carbon dioxide -393.5 Water (l) -285.9 Oxygen 0.0

### Chemistry

A calorimeter contains 30.0 mL of water at 15.0 C. When 1.50 g of X (a substance with a molar mas of 46.0g/ mol is added, it dissolves via the reaction X (s) + H2O (l) ----> X (aq) and the temperature of the solution increases to 26.5 C. Calculate the enthalpy change for ...

### Chemistry

Calculate the temperature change in the water upon complete melting of the ice. Hint: Determine how much heat is absorbed by the melting ice and then use q =mC*Delta T to calculate the temperature change of the 314 g of water. under the following conditions: A 14.7 g ice cube ...

### CHEMISTRY

The enthalpy of cimbustion for Octane vapor, C8H18, a component of gasoline, is -5512.0kJ/mol. a. Write the equation for the combustion of Octane, including the energy term. b. Calculate the energy change when 45g of Octane burn. c. Calculate the energy produced when 45g of ...

### Chemistry

Which of the following reactions are spontaneous (favorable)? A] 2Mg(s) + O2(g) -> 2MgO(s) Delta G = -1137 kJ/mol .. B] NH3(g) + HCl(g) -> NH4Cl(s) Delta G = -91.1 kJ/mol ... C] AgCl(s) -> Ag+(aq) + Cl-(aq) Delta G = 55.6 kJ/mol .. D] 2H2(g) + O2(g) -> 2H2O(g) ...

### Chemistry

3.25g of zinc was added to 50cm^3 of a 4.0 molar dm^-3 HCl. When the reaction was completed the temperature rose by 28 degrees celcius. (a) Is the reaction exothermic or endothermic? (b)All the zinc dissolve in this reaction. How many moles of zinc reacted? (c) How many moles ...

### chemistry

If heat of reaction, Ca(s) + 2H+(aq) Ca2+(aq) + H2(g) , is - 544 kJ/mol, heat of reaction, CaO(s) + 2H+(aq) Ca2+(aq) + H2O(l) , is -192 kJ/mol. and heat of formation of water is -286, what is heat of CaO? Ca(s) etc is equation 1. CaO + 2H^+ etc is equation 2. H2 + 1/2 O2 ==>...

### Chemistry 143

Write three thermochemical equation needed to calculate delta H for the following reaction: 2Mg(s) + O2(g) = 2MgO Include delta h values in kJ for each reaction. Please help!! I don't even know were to start!!

### Chemistry

The molar solubility of lead iodide is 1.45*10^-3M at 20 degrees C and 6.5*10^-3M at 80 degrees C . What are the values of delta H not and delta S not for dissolution of PbI2 ? PbI2(s) ---> Pb2+(aq) + 2I- (aq) You may assume that delta H and delta S are independent of ...

### science, chemistry

2Al(s)+ 3Cl2(g)=2AlCl3(s) For the above reaction calculate: A) delta H, then state whether the reaction is endothermic or exothermic B) delta s, then whether the reaction becomes more or less disorder. C) delta G, the state whether the reaction is spontaneous or non-spontaneous

### college chemistry

The chemical reaction representing production of water gas is as follows: C(s)+H2O(l)=CO(g)+H2(g) calculate the enthalpy change in the production of 200L(at 500mmHg and 65degree celcius) of hydrogen by this reaction.

### Thermodynamics

Consider a system consisting of 2.0 mol Carbon dioxide gas, inititially at 25 deg and 10 atm and confined to a cylinder of cross section 10.0square centimeters. lt is allowed to expand adiabatically against an external pressure of 1.0atm until the piston has moved outwards ...

### chemistry

You measure Ksp for borax and find it to be 6.2 x 10-3 at 22.8°C. If the standard enthalpy change, ΔH°, for the dissolution of borax is 58 kJ, calculate the standard entropy change, ΔS°, (in J/K) for the dissolution of borax at this temperature. (Assume ΔH° ...

### Chemistry 1150

Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin plastic divider. When the divider is broken, the ammonium nitrate dissolves according to the following endothermic reaction: NH4NO3(s)→NH+4(aq)+NO...

### Chemistry

using a coffee calorimeter, it is found that when an ice cube weighing 24.6g melts, it absorbs 8.19kJ of heat. calculate delta H for the phase change represented by the thermochemical equation: H2O(s) ->H2O(l)

### Chemistry

2CO(g) = 2C(s) + O2(g). A sample of 0.882g of carbon monoxide, CO(g), is completely decomposed in a calorimeter containing 325 g of water. The initial temperature is 17.60*C, and the final temperature is 74.21*C. Calculate the enthalpy change in J/mol of reactant. I hope that'...

### chemsitry

c. Use the enthalpy diagram provided above and apply Hess’s Law to determine the standard enthalpy of formation for C12O36H20N12 (s) using the results from part (a) and the following values: The standard enthalpy of formation of gaseous carbon dioxide is -393.5 kJ/mol The ...

### Chemistry

The delta G^o for a reaction : h2 (g) + i2 (g) = 2HI(g) Is 2.6 kj/moles. In one experiment the initial pressures are P h2 = 4.26 atm, P i2 = 0.024 atm, P hi = 0.23 atm. Calculate delta G

### Chemistry

Calculate the change in enthalpy for the following reaction: C25H52(g) + O2(g) → CO2(g) + H2O(l) I started off by balancing the equation: C25H52(g) + 38O2(g) → 25CO2(g) + 26H2O(l) Can someone help me with the rest.

### Chemistry

If 0.812g of calcium reacts in a coffee-cup calorimeter that contains 400.0g of water/ The initial temperature of the water is 17.9°C, the final temperature is 26.0°C. Calculate the standard molar enthalpy change for this reaction.

### chemistry

A scientist measures the standard enthalpy change for the following reaction to be -53.4 kJ : Ca(OH)2(aq) + 2 HCl(aq) CaCl2(s) + 2 H2O(l) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of H2O(l) is kJ/mol