Question

Suppose you wanted to heat a rhug of water (136 mL) from room temperature 12 °C to78 °C to make a cup of tea. How much energy (in units of joules) would you need fromyour microwave? (Cwater 4.184 J/g°C)Is 37,556.584 correct?

Answer 1

37,555.584 Joules

Explanations

The formula for calculating the amount of energy needed is expressed as:

`Q=mc\triangle t`

where:

• m is the ,mass, of water = 136grams

,

• c is the ,specific heat, capacity of water = 4.184 J/g°C

,

• △t is the change in ,temperature, = 78 - 12 = 66°C

Substitute

`\begin{gathered} Q=136g*(4.184J)/(g^oC)*66^0C \\ Q=37,555.584Joules \end{gathered}`

Hence the amount of energy that is needed is 37,555.584 Joules