Question

ice cube (25g) is at -8.0°c. how much energy is required to completely melt it. heat (°c) for solid water is 2.10 j/g°c. hf = 334 j/g

Explanation:

Step1: Calculate heat to raise ice temperature to 0°C

Use formula \(Q = mc\Delta T\). Here, \(m = 25g\), \(c = 2.10J/g^{\circ}C\), \(\Delta T=0 - (- 8.0)=8.0^{\circ}C\).
\(Q_1=25\times2.10\times8.0\)
\(Q_1 = 420J\)

Step2: Calculate heat to melt ice

Use formula \(Q = mH_f\). Here, \(m = 25g\), \(H_f=334J/g\)
\(Q_2=25\times334\)
\(Q_2 = 8350J\)

Step3: Calculate total heat

\(Q_{total}=Q_1 + Q_2\)
\(Q_{total}=420 + 8350\)
\(Q_{total}=8770J\)

Answer:

\(8770J\)