Chemistry, 10.03.2020 00:25, skylar7192

Calculate ΔHrxn for the following reaction: Fe2O3(s)+3CO(g)→2Fe(s)+3CO2(g) Use the following reactions and given ΔH values: 2Fe(s)+32O2(g)→Fe2O3(s),ΔH CO(g)+12O2(g)→CO2(g),ΔH==−824.2kJ−2 82.7kJ

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answered: janicemaxwell123

Answer : The value of $\Delta H_{rxn}$ is, -23.9 kJ

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

The main reaction is,

$Fe_2O_3(s)+3CO(g)\rightarrow 2Fe(s)+3CO_2(g)$ $\Delta H=?$

The intermediate balanced chemical reaction will be,

(1) $2Fe(s)+\frac{3}{2}O_2(g)\rightarrow Fe_2O_3(s)$ $\Delta H_1=-824.2kJ$

(2) $CO(g)+\frac{1}{2}O_2(g)\rightarrow CO_2(g)$ $\Delta H_2=-282.7kJ$

We are reversing reaction 1 and multiplying reaction 2 by 3 and then adding all the equations, we get :

(1) $Fe_2O_3(s)\rightarrow 2Fe(s)+\frac{3}{2}O_2(g)$ $\Delta H_1=824.2kJ$

(2) $3CO(g)+\frac{3}{2}O_2(g)\rightarrow 3CO_2(g)$ $\Delta H_2=3\times (-282.7kJ)=-848.1kJ$

The expression for enthalpy of the reaction is:

$\Delta H=\Delta H_1+\Delta H_2$

$\Delta H=(824.2kJ)+(-848.1kJ)$

$\Delta H=-23.9kJ$

Therefore, the value of $\Delta H_{rxn}$ is, -23.9 kJ

answered: Guest

Atomicity occurs to prevent updates of the database occurring only partially, which can cause greater problems than rejecting the whole series outright.some are monatomic, diatomic, triatomic etc because it shows the number of atoms. for example, monatomic means it contains only one atom.

answered: Guest

Answer: abeexplanation:

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

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Calculate ΔHrxn for the following reaction: Fe2O3(s)+3CO(g)→2Fe(s)+3CO2(g) Use the following reactio...