# chemistry

Consider the hypothetical elements X and Y. Suppose the enthalpy of formation for the compound XY is ƒ{336 kJ/mol, the bond energy for X2 is 414 kJ/mol, and the bond energy for Y2 is 159 kJ/mol. Estimate the XY bond energy in units of kJ/mol.

1. 👍 0
2. 👎 0
3. 👁 166
1. X2 + Y2 => 2XY delta H format = 2*336 kJ.

X2 = 414 = bond energy = B.E.
Y2 = 159
(sum B.E.reactants-sum B.E. products) = delta H rxn.
(414+159)-(2*B.E. products)= -672
NOTE: It isn't clear to me what the sign is for delta Hf for XY. I have assumed you intended to type a - sign; however, whatever the sign is for delta Hf that goes in for the 672. I have multiplied by 2 since there are two moles involved.
You can work out the B.E. products as the only unknown in the equation. You can check the number by the following:
[(414/2)+(150/2)]-(B.E. product you calculate) = delta Hf.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### chemistry

Consider the hypothetical elements X and Y. Suppose the enthalpy of formation for the compound XY is -336 kJ/mol, the bond energy for X2 is 414 kJ/mol, and the bond energy for Y2 is 159 kJ/mol. Estimate the XY bond energy in units

asked by Jude on December 13, 2010
2. ### Chemistry (metals)

I had a problem in which I had to work out the standard enthalpy of formation for MgBr(s)…assuming it exits. I've done that using various bits of given data and got a value of –93.5kJmol^-1…not sure if the actual answer is

asked by Wx Girl on May 3, 2007
3. ### chemistry

The enthalpy of formation of C2H5OH is -238.7 kJ/mol. What information does this reveal about the bonds in the molecule? A. Bond formation in C2H5OH from its elements only occurs in cold temperatures. B. Bond formation in C2H5OH

asked by Morgan on December 9, 2014
4. ### AP Chemistry

Under what circumstances is the enthalpy of formation of a compound from its elements usually: - positive - negative

asked by Jesse on April 13, 2018
5. ### Chemistry

You wish to know the enthalpy change for the formation of liquid PCl3 from the elements shown below. P4(s) + 6 Cl2(g)--> 4 PCl3(l) ΔH°f = ? The enthalpy change for the formation of PCl5 from the elements can be determined

asked by Kat on May 1, 2011
6. ### 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

asked by Nora on October 23, 2010
7. ### chemistry

2.9 The standard enthalpy of formation of the metallocene bis(benzene)chromium was measured in a calorimeter. It was found for the reaction Cr(C6H6)2(s) → Cr(s) + 2 C6H6(g) that . Find the corresponding reaction enthalpy and

asked by girlgirl on June 18, 2011
8. ### 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

asked by alexandra on July 13, 2010
9. ### Chemistry

calculate the enthalpy change for: (enthalpy of formation of aqueous sodium hydroxide is -469.60 kJ/mol. enthalpy of formation of liquid water is -285.8 kJ/mol) 2Na + 2H2O = 2 NaOH + H2

asked by Annie on January 31, 2013
10. ### Chemistry

The enthalpy of formation for a substance corresponds to the enthalpy change for a reaction. Write the specific chemical reaction defining the enthalpy of formation of butane: Just checking to make sure this is correct: 4C + 5H2

asked by AJ on March 26, 2017

More Similar Questions