Question

How much heat will be released when 6.44g of Sulfer reacts with excess O2 according to the following equation.2S +3O2 --> 2SO3 ∆H° = -791.4kJ

Answer 1

-79.14kJ

Step-by-step explanation:

1st) In the balanced reaction 791.4kJ are released when 2 moles of sulfur (S) react, so it is necessary to convert the 6.44g to moles, using the sulfur atomic mass (32g/mol):

`6.44g*(1mole)/(32g)=0.2moles`

So, in this case, only 0.2 moles of sulfur will react.

2nd) Now, with a mathematical rule of three we can calculate the heat that will be released using 0.2 moles of S:

`\begin{gathered} 2moles-791.4kJ \\ 0.2moles-x=(0.2moles*791.4kJ)/(2moles) \\ x=79.14kJ \end{gathered}`

Finally, 79.14kJ will be released when 6.44g of S react with O2.