Question

How much energy is released when 16.5 g of steam is condensed at 100°C if the heat of vaporization is 2260 J/g?

Answer 1

Approx. `37*kJ`........

Explanation:

We are given data for water's vaporization......

`H_2O(l) + Delta_1rarrH_2O(g)`

Where `Delta_1=2260*kJ*g^-1`........

Note that by convention, EXOTHERMIC REACTIONS are reported with a negative sign, whereas, as here, ENDOTHERMIC reactions are reported with a positive sign.

Now we interrogate the physical reaction......

`H_2O(g) rarr H_2O(l) + Delta_1`

And a `16.5*g` mass of steam condenses, and so we take the product.......

`16.5*gxx-2260*kJ*g^-1=??*kJ`.