Question

If the temperature of 34.4 g of ethanol increases from 25 °C to 78.8 °C, how much heat has been absorbed by the ethanol? The specific heat of ethanol is 2.44 J/(gC)?

Answer 1

The ethanol has absorbed `"4500 J"`.

Explanation:

Use the following formula:

`q=mcDeltat`,

where `q` is energy in Joules, `m` is mass, `c` is specific heat capacity, and `Deltat` is change in temperature: `Deltat=(T_"final"-T_"initial")`

Organize your data:

Known

`m="34.4 g"`

`c=("2.44 J")/("g"*"C"^@")`

`T_"initial"="25"^@"C"`

`T_"final"="78.8"^@"C"`

`Deltat=78.8^@"C"-25^@"C"="54"^@"C"`

Unknown

`q`

Insert you data into the formula and solve.

`q=(34.4color(red)cancel(color(black)("g")))xx((2.44"J")/(color(red)cancel(color(black)("g"))*""^@color(red)cancel(color(black)("C"))))xx(54^@color(red)cancel(color(black)("C")))="4500 J"` (rounded to two significant figures)