Answer to Question #317519 in General Chemistry for Mave

Question

Example:

Decomposition of mercuric oxide HgO to mercury Hg and oxygen O2 gas, requires

87.1kJ of heat,

HgO(s)  Hg(l) + O2(g) ΔH = + 87.1kJ (needs to absorb energy)

1. Combustion of hexane, C6H12 to carbon dioxide gas and water, releases 3923.9kJ

of heat.

2. Reaction between solid phosphorous, P4 and oxygen gas, produces P3O6 and

1640.1kJ of heat.

3. One mole ammonium nitrate (NH4NO3) dissolves in water to produce aqueous

ammonium ions and nitrate ions accompanied by the absorption of 28.1 kJ of heat.

4. Formation of carbon dioxide gas from carbon (graphite) and oxygen yields 393.5

kJ of heat.

Please solve it like this

1. Answer

2. Answer

3. Answer

4. Answer

Answer 1

1.  Combustion of hexane, C6H12 to carbon dioxide gas and water, releases 3923.9kJ

of heat.

$C_6H_{12} + 9O_2 \longrightarrow 6CO_2 + 6H_2O$ $\Delta H= -3923.9kJ$

2 . Reaction between solid phosphorous, P4 and oxygen gas, produces P3O6 and

1640.1kJ of heat.

$3P_4 + 12O_2 \longrightarrow 4P_3O_6$ $\Delta H= -1640.1kJ$

3 . One mole ammonium nitrate (NH4NO3) dissolves in water to produce aqueous

ammonium ions and nitrate ions accompanied by the absorption of 28.1 kJ of heat.

$NH_4NO_3\longrightarrow (NH_4)^+ +(NO_3)^{-1} , \Delta H= +28.1kJ$

4 . Formation of carbon dioxide gas from carbon (graphite) and oxygen yields 393.5

kJ of heat.

$C(s) + O_2(g) \longrightarrow CO_2(g), \Delta H= -393.5kJ$