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Elena-2011 [213]
2 years ago
14

Study the reactions.

Chemistry
1 answer:
yulyashka [42]2 years ago
3 0

Answer:

\displaystyle \Delta H = -2426\text{ kJ}

Explanation:

To find the enthalpy change of the target reaction, we can use Hess's Law.

Reversing the third reaction yields:

\displaystyle \text{C$_3$H$_8$(g)} \longrightarrow 3\text{C(s)} + 4\text{H$_2$(g)}\;\;\;\;\;\Delta H = -106\text{ kJ}

Multiplying the first reaction by three yields:

\displaystyle 3\text{C(s)} + 3\text{O$_2$(g)} \longrightarrow 3\text{CO$_2$}(g)}\;\;\;\;\; \Delta H = -1.18\times 10^3\text{ kJ}

Multiplying the second reaction by four yields:

\displaystyle 4\text{H$_2$(g)} + 2\text{O$_2$(g)} \longrightarrow 4\text{H$_2$O($\ell$)} \;\;\;\;\;  \Delta H = -1.14\times 10^3 \text{ kJ}

Adding all equations yield:

\displaystyle \text{C$_3$H$_8$(g)} + 5\text{O$_2$(g)} \longrightarrow 3\text{CO$_2$(g)} + 4\text{H$_2$O($\ell$)} \;\;\;\;\; \Delta H = -2426\text{ kJ}

Hence, the enthalpy change of the target reaction is -2426 kJ.

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melisa1 [442]

Mass CoCl2 = 10.27 g
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3 years ago
How many kilograms of chlorine are in 21 kg of CF2Cl2
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Please help!! i need the answer ASAP!
nirvana33 [79]

Answer:

23.34 %.

Explanation:

  • The percentage of water must be calculated as a mass percent.
  • We need to find the mass of water, and the total mass in one mole of the compound. For that we need to use the atomic masses of each element and take in consideration the number of atoms of each element in the formula unit.
  • <em>Atomic masses of the elements:</em>

Cd: 112.411 g/mol, N: 14.0067 g/mol, O: 15.999 g/mol, and H: 1.008 g/mol.

  • <em>Mass of the formula unit:</em>

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  • <em> Mass of water in the formula unit:</em>

<em>mass of water</em> = (4 × 2 × 1.008 g/mol) + (4 × 15.999 g/mol) = 72.0 g/mol.

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