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3 years ago

How is enthalpy used to predict whether a reaction is endothermic or exothermic?

1 answer:

8 0

If the enthalpy change is negative, then the reaction is exothermic because heat energy was lost to the surroundings.

If the enthalpy change was positive, then the reaction was endothermic because heat energy was gained from the surroundings!

Hope this helps!! x

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Carbon tetrachloride can be produced by the following reaction: Suppose 1.20 mol of and 3.60 mol of were placed in a 1.00-L flas

hjlf

The given question is incomplete. The complete question is :

Carbon tetrachloride can be produced by the following reaction:

$CS_2(g)+3Cl_2(g)\rightleftharpoons S_2Cl_2(g)+CCl_4(g)$

Suppose 1.20 mol $CS_2(g)$ of and 3.60 mol of $Cl_2(g)$ were placed in a 1.00-L flask at an unknown temperature. After equilibrium has been achieved, the mixture contains 0.72 mol of $CCl_4$ . Calculate equilibrium constant at the unknown temperature.

Answer: The equilibrium constant at unknown temperature is 0.36

Explanation:

Moles of $CS_2$ = 1.20 mole

Moles of $Cl_2$ = 3.60 mole

Volume of solution = 1.00 L

Initial concentration of $CS_2$ = $\frac{moles}{volume}=\frac{1.20mol}{1L}=1.20M$

Initial concentration of $Cl_2$ = $\frac{moles}{volume}=\frac{3.60mol}{1L}=3.60M$

The given balanced equilibrium reaction is,

$CS_2(g)+3Cl_2(g)\rightleftharpoons S_2Cl_2(g)+CCl_4(g)$

Initial conc. 1.20 M 3.60 M 0 0

At eqm. conc. (1.20-x) M (3.60-3x) M (x) M (x) M

The expression for equilibrium constant for this reaction will be,

$K_c=\frac{[S_2Cl_2]\times [CCl_4]}{[Cl_2]^3[CS_2]}$

Now put all the given values in this expression, we get :

$K_c=\frac{(x)\times (x)}{(3.60-3x)^3\times (1.20-x)}$

Given :Equilibrium concentration of $CCl_4$ , x = $\frac{moles}{volume}=\frac{0.72mol}{1L}=0.72M$

$K_c=\frac{(0.72)\times (0.72)}{(3.60-3\times 0.72)^3\times (1.20-0.72)}$

$K_c=0.36$

Thus equilibrium constant at unknown temperature is 0.36

4 0

2 years ago

On a cold morning, the smoke coming out of a chimney is observed to be in blue color. What could be the reason? Name the effect

nirvana33 [79]

Stack effect? I'm not totally sure about this...

Explanation:

Large amount of tiny particles of water droplets, dust and smoke are present on a misty day. These tiny particles in the air scatter blue colour of white light passing through it. When this scattered light reaches our eyes, the smoke appears blue.

6 0

3 years ago

Oxidation state of Nitrogen in N2O5

balandron [24]

Explanation:

Oxidation state of Nitrogen in N2O5 is +5

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1 year ago

What elements react the most? Like have the most reactivity.

Vera_Pavlovna [14]

If you mean what group of elements react the most, the answer is the alkali metals and the halogens because they both only either need to gain or lose one electron. If you mean the most reactive element, it would be fluorine because it has the most electronegativity.

4 0

3 years ago

What would scientist’s next steps be if his/her data supported his/her hypothesis?

Lady bird [3.3K]

To communicate the results in an organized report

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3 years ago

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