Sand is converted to pure silicon in a three step process. the third step is sicl4 (g) + 2mg (s) → 2mgcl2 (s) + si (s) δh = - 625.6 kj what is the enthalpy change when 25.0 mol of silicon tetrachloride is converted to elemental silicon? multiple choice - 7820 kj - 25.0 kj - 3.13 * 104 kj none of these choices are correct. - 1.56 * 104 kj

Question

Chemistry

Jacob Keith

12 March, 01:20

Sand is converted to pure silicon in a three step process. the third step is sicl4 (g) + 2mg (s) → 2mgcl2 (s) + si (s) δh = - 625.6 kj what is the enthalpy change when 25.0 mol of silicon tetrachloride is converted to elemental silicon? multiple choice - 7820 kj - 25.0 kj - 3.13 * 104 kj none of these choices are correct. - 1.56 * 104 kj

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Eliana Mcgee · Answer 1

The reaction is that,

1 mole is SiCL4 will produce 1 mole of Si (s) Since there is 1 to 1 relationship then we just multiply the enthalpy of reaction by the number of moles

Enthalpy = - 625.5 kJ/mole * 12.5 Moles

= - 7,818.75 KJ

= - 0.78 * 10⁴KJ