Question

Using the equations and enthalpy values provided, which mathematical expression can be used to determine the unknown enthalpy change represented by x?

3 C + 3 O2 3 CO2 H = -1182 kJ

4 H2 + 2 O2 4 H2O H =-1144 kJ

C3H8 + 5 O2 3 CO2 + 4 H2O H = x

C3H8 3 C + 4 H2 H = 104 kJ

104 = (-1182) + (-1144) + x

104 = x + (-1182) - (-1144)

104 = x - [(-1182) + (-1144)]

104 = (-1182) - [x + (-1144)]

Answer 1

@Abhisar could you explain this to me ? :)

Answer 2

It's easy one honey !

Answer 3

haha really ?⊙.☉

Answer 4

All the terms which are common to both LHS and RHS will get cancelled out
\(\color{blue}{\text{Originally Posted by}}\) @Abhisar
\(\large \sf \cancel{3 C} + 3 O_2-->3 CO_2 ~~~~~~~~H = -1182 kJ\\

\large \cancel{4 H_2} + 2 O_2-->4 H_2O ~~~~~~~~H =-1144 kJ\\

\large C3H8-->\cancel{3 C} + \cancel{4 H2}~~~~~~~H = 104 kJ\)

Now we will have to simply add these equations
\(\color{blue}{\text{End of Quote}}\)

Answer 5

Getting it ?

Answer 6

LHS=left hand side and RHS=Right hand side

Answer 7

ok so far ?

Answer 8

wait what are you crossing out ?

Answer 9

Those are common terms on both sides of the equation.

Answer 10

Like 3C is on both the sides.

Answer 11

i see !

Answer 12

so shall we proceed ?

Answer 13

yes

Answer 14

Now let's see what is left

Answer 15

\(\sf \large C_3H_8 + 5 O_2-->3 CO_2 + 4 H_2O\)...ok ?

Answer 16

yes i am following

Answer 17

NOTE: we simply added all the three equation which gave us the fourth one

Answer 18

No let's see on whole



\(\large \sf \cancel{3 C} + 3 O_2-->3 CO_2 ~~~~~~~~H = -1182 kJ\\

\large \cancel{4 H_2} + 2 O_2-->4 H_2O ~~~~~~~~H =-1144 kJ\\

\large C3H8-->\cancel{3 C} + \cancel{4 H2}~~~~~~~H = 104 kJ\)
____________________________________________________________________________

\(\sf \large C_3H_8 + 5 O_2-->3 CO_2 + 4 H_2O\)~~~H=[-1182+(-1144)+(-104)]

Answer 19

ok ?

Answer 20

o yes

Answer 21

so x = ?

Answer 22

do i have to add them ?

Answer 23

YAS

Answer 24

-1182+(-1144)+(-104) = -2430

Answer 25

\(\color{blue}{\text{Originally Posted by}}\) @Abhisar
No let's see on whole



\(\large \sf \cancel{3 C} + 3 O_2-->3 CO_2 ~~~~~~~~H = -1182 kJ\\

\large \cancel{4 H_2} + 2 O_2-->4 H_2O ~~~~~~~~H =-1144 kJ\\

\large C3H8-->\cancel{3 C} + \cancel{4 H2}~~~~~~~H = 104 kJ\)
____________________________________________________________________________

\(\sf \large C_3H_8 + 5 O_2-->3 CO_2 + 4 H_2O\)~~~H=[-1182+(-1144)+(104)]
\(\color{blue}{\text{End of Quote}}\)

Answer 26

sorry i just realised....104 is positive

Answer 27

yup

Answer 28

so x = -1182-1144+104=2222

Answer 29

got it ?

Answer 30

yea

Answer 31

so what is next ? ;)

Answer 32

It's the answer.....x=2222

Answer 33

oooh that all ?!? thank you =)

Answer 34

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\(~~~~~~~~~~~~~~~~~~~~~~~~~~~\color{green}{\huge\ddot\smile}\color{blue}{\huge\ddot\smile}\color{pink}{\huge\ddot\smile}\color{red}{\huge\ddot\smile}\color{yellow}{\huge\ddot\smile}\)

Answer 35

i found this poem that describes you!! :)

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I appreciate everything that you do,
Very helpful and thoughtful too.
From the beginning, you've been there for me,
When I was down, you were strong like a tree.
You offer so much, a heart that is kind,
Thinking to help others, in your beautiful mind.
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Everything you do, I respect and praise,
You're a wonderful person, you always amaze.
Wish to say thank you, deep in my heart,
For so many lives, you're a big part.

Answer 36

Awee sho shweet
*touched

Answer 37

Thank you very much
\(\Huge{\overset{\frown}{\normalsize
\left(
\begin{matrix}
\Large\cdot \quad \cdot\\
\cdot\\
\huge \smile
\end{matrix}
\right)}}\normalsize
\\
\;/\quad \;\;\quad \backslash\)

Answer 38

yes of course!

Answer 39

The poem is really cute.

Answer 40

I know <3

Answer 41

\(\color{green}{\huge\ddot\smile}\)

Answer 42

could i ask some more questions ? :)

Answer 43

YAS..Go ahead !