Question

during the day water heats to a gas under the hot arizona sun, once the sun sets the water then cools down to a liquid that can be seen as dew on the grass. if 148g of gas is made by the sun measuring at a temp of 100°c cools down to a liquid that can liquid at night measured at a temp of 42°c, how much total energy is released during this phase and temperature change? specific heat of water is 4.184 j/g°c. hv = 2260 j/g. a -85347 j b 85347 j c 370395 j d -370395 j

Explanation:

Step1: Calculate heat released during phase change

Heat released during phase change \(Q_1=-m\times Hv\), where \(m = 148g\) and \(Hv=2260J/g\)
\(Q_1=-148\times2260=-334480J\)

Step2: Calculate heat released during temperature change

Heat released during temperature change \(Q_2 = m\times c\times\Delta T\), where \(m = 148g\), \(c = 4.184J/g^{\circ}C\), \(\Delta T=42 - 100=- 58^{\circ}C\)
\(Q_2=148\times4.184\times(-58)\)
\(Q_2=148\times(-242.672)=-36015.456J\)

Step3: Calculate total heat released

Total heat released \(Q = Q_1+Q_2\)
\(Q=-334480+(-36015.456)=-370495.456J\approx - 370395J\)

Answer:

D. -370395 J