Hard water contains high levels of minerals such as magnesium and calcium and can be a real pain to remove if left untreated. When hard water is boiled in an electric kettle, these minerals do not evaporate like the water does but instead remains in the kettle.
By law of conservation of energy, the amount of heat lost
by the metal should be equal to the amount of heat gained by water. That is,
the change in energy (expressed in enthalpies) should be equal:
- (ΔH)metal = (ΔH)water
Take note of the negative sign in front of (ΔH)metal, this
means that heat is lost by this metal.
Where ΔH or change in enthalpy is:
ΔH = m Cp (T2 – T1)
So,
- 15 g (Cp) (23 °C – 99 °C) = 75 g (4.18 J/g * °C) (26 °C –
23 °C)
1,140 Cp = 940.5
<span>Cp = 0.825 J/g * °C (ANSWER)</span>
Chemistry is a major part of science that discusses the elements and basic substances of forms of life. It helps investigate how things grow and change and how they react over time.
What is the question that needs an answer?