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solong [7]
3 years ago
9

Hydrazine (N2H4) is used as a rocket fuel. The combustion products are nitrogen (N2) and water (H2O). Use the following informat

ion about bond energies to estimate the change in enthalpy associated with the combustion of 1 mol of hydrazine
Bond Bond Energy (kJ/mol)

N–N 163

N=N 418

N N 941 <- triple bond

N–H 388

O–O 146

O=O 495

O–H 463

a. −583 kJ/mol d. −358 kJ/mol b. +2,450 kJ/mol e. −1,970 kJ/mol c. −1,078 kJ/mol
Chemistry
1 answer:
kykrilka [37]3 years ago
7 0

Answer:

a. −583 kJ/mol

Explanation:

First we start with the balanced chemical equation

N2H4 + O2 ------> N2 + 2 H2O

Breaking bonds is endothermic, it requires energy whereas bond forming is exothermic, it expels energy. So the net energy change during this reaction can be calculated this way

ΔH = bond breaking energy - bond forming energy

     = (4*388+163 + 495) - (941+4*463)

    = -583 kJ/mol

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See explanation below

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6 0
3 years ago
Suppose a graduated cylinder were not correctly calibrated. how would this affect the results of a measurement? how would it aff
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The volume measurements won't be accurate and will be either less than or more than the anticipated figure if the graduated cylinder is accurately calibrated (depending on if the error in calibration is higher or lower). Depending on the calibration error, the calculated value may be higher or lower than the real value.

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Setting up an instrument so that it can generate findings for samples that fall within a tolerable range is part of the calibration process. A key component of instrumentation design is eliminating or reducing conditions that lead to faulty measurements.

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2 years ago
these elements are the least likely to become involved in chemical reaction a) alkali metals b) halogens c) noble gases d) trans
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3 years ago
Read 2 more answers
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