PLEASE HELP ME WITH THIS CHEM WORK!!!
I’LL GIVE A BRAINIEST TO WHOEVER GETS IT RIGHT:)


1.) 50.0 grams of water at 100 degrees Celsius evaporated to water vapor 2 points
at 100 degrees Celsius. Calculate the amount of heat required for this
conversion.

2.) A student measured 15.0 grams of ice in a beaker. The beaker was then
placed on a hot plate where it was heated uniformly for a certain amount
of time. During the melting process of the ice, the student noted that the
temperature was at 0 degree Celsius. When all the ice converted to water,
the final temperature was also at 0 degree Celsius. How much heat was
used to melt the ice?

Respuesta :

1. Q = 112.8 kJ

2. Q = 5.01 kJ

Further explanation

The heat to change the phase can be formulated :

Q = mLf (melting/freezing)

Q = mLv (vaporization/condensation)

Lf=latent heat of fusion

Lv=latent heat of vaporization

1. m=50 g=0.05 kg

Lv for water = 2256 kJ/kg

[tex]\tt Q=m.L_v\\\\Q=0.05\times 2256\\\\Q=\boxed{\bold{112.8~kJ}}[/tex]

2. m=15 g=0.015 kg

Lf for water = 334 kj/kg

[tex]\tt Q=m.L_f\\\\Q=0.015\times 334\\\\Q=\boxed{\bold{5.01~kJ}}[/tex]