Chemistry, 19.05.2020 03:17 Redhead667

1.What mass of oxygen gas, O2, from the air is consumed in the combustion of 702g of octane, C8H18, one of the principal components of gasoline? 2C8H18 + 25O2 -> 16CO2 + 18H2O.

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Answer from: rhettperkins

Approximately $2.46\times 10^3\; \rm g$ .

Explanation:

Molar mass of C₈H₁₈ and O₂

Look up the following relative atomic mass values on a modern periodic table:

$\rm C$ :

. $\rm H$ : 1.008

. $\rm O$ : 15.999

Calculate the molar mass of octane, $\rm C_8 H_{18}$ :

$M(\rm C_8 H_{18}) = 8 \times 12.011 + 18 \times 1.008 = 114.232\; \rm g \cdot mol^{-1}$ .

Similarly, calculate the molar mass of $\rm O_2$ :

$M(\mathrm{O_2}) = 2 \times 15.999 = 31.998 \; \rm g \cdot mol^{-1}$ .

Number of moles of octane molecules

How many moles of molecules in $702\; \rm g$ of octane, $\rm C_8 H_{18}$ ?

$\displaystyle n({\rm C_8 H_{18}}) = \frac{m({\rm C_8 H_{18}})}{M({\rm C_8 H_{18}})} = \frac{702\; \rm g}{114.232\; \rm g \cdot mol^{-1}}\approx 6.1454\; \rm mol$ .

Number of moles of O₂ required

Make sure that the chemical equation here is balanced.

In this equation,

The coefficient of $\rm O_2$ is

, whileThe coefficient of $\rm C_8 H_{18}$ is

Ratio between the two coefficients:

$\displaystyle \frac{\text{Coefficient of $\mathrm{O_2}$}}{\text{Coefficient of $\mathrm{C_8H_{18}}$}} = \frac{25}{2}$ .

Therefore:

$\displaystyle \frac{n(\mathrm{O_2},\, \text{consumed})}{n(\mathrm{C_8H_{18}},\, \text{consumed})} = \frac{25}{2}$ .

Rearrange to obtain:

$\displaystyle n(\mathrm{O_2},\, \text{consumed}) = \frac{25}{2}\times n(\mathrm{C_8H_{18}},\, \text{consumed})$ .

It is already determined that $\displaystyle n({\rm C_8 H_{18}})\approx 6.1454\; \rm mol$ . Hence, the number of moles of oxygen gas required will be:

$\begin{aligned}& \frac{25}{2}\times n(\mathrm{C_8H_{18}}) \approx \frac{25}{2}\times 6.1454\; \rm mol \approx 76.817\; \rm mol\end{aligned}$ .

Mass of O₂ required

What would be the mass of that $76.817\; \rm mol$ of $\rm O_2$ ?

$\begin{aligned}&m({\rm O_2}) \\ &= n({\rm O_2}) \cdot M({\rm O_2})\\ &\approx 76.817\; \rm mol \times 31.998\; \rm g \cdot mol^{-1} \\ &\approx 2.46\times 10^3\; \rm g\end{aligned}$ .

Answer from: Quest

when—without warning—something provokes your anger, you may struggle not to succumb to it. since what typically makes you mad is feeling powerless in the face of what seems unfair, your anger is mostly an attempt at a “quick fix” to right the balance. it’s as though you’re raising a fist in protest, proclaiming that you’re not going to capitulate to such injustice.

there are, however, a multitude of problems related to this immediate, push-back reaction of anger. and probably the key one is that almost never does it resolve the issue that gave rise to it. such reactive anger is probably best understood as self-defeating. as david burns, the author of the seminal self- book feeling good, observes: if realistically, acting on your anger is to make any sense, it needs to meet two criteria—which, in almost every case, is frankly impossible. that is, your anger must:

be directed toward a person who has intentionally (and needlessly) behaved in a hurtful way toward you; and

be beneficial or advantageous to you (i.e., assist you in achieving a desired goal).

i think you’ll agree that only rarely can you claim that your anger is both warranted and , whether to yourself or the relationship.

so let me offer you a two-step alternative to abandoning your better judgment and giving in to the temptation of anger—one that should neutralize your anger in seconds. or, when you’re really angry, in minutes.

but keep in mind that you must really want to execute these steps, be sufficiently motivated to perform them. which means overcoming more unconscious resistance than you might ever have imagined. because there are many immediate “advantages” of anger that can interfere with your resolve, i’ll suggest a few of them that might interfere with your employing this powerful method to rid yourself of counter-productive anger.

explanation:

Answer from: Quest

the food using pesticides in the future will harm you by giving you diseases like cancer or something since they have things that we should not eat in it like chemicals or pesticides. that is why organic food is more expensive because they take the time to make it right and healthy for you to eat.

explanation:

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