How much heat is released when 85.0 grams of liquid water freezes to ice, at 0 degrees celcius

To calculate the amount of heat entering or leaving a system, the equation Q=mcΔT is used.

m = mass (in grams)
c = specific heat capacity (J/g°C)
ΔT = change in temperature (°C)

Here, we will use the specific heat capacity for liquid water which is 4.19 J/g°C.

The mass given is 25.0 grams.

As for the change in temperature, I will assume that it start off at room temperature, 25°C.

25°C−0°C=25°C

Q=mcΔT

Q=25grams⋅4.19Jg°C⋅25°C

Q=2618.75J

Take into account significant figures and the answer should be

2.6⋅103J

the number of valence electrons for each molecule or ion is shown beneath the structure. remember hydrogen will not have more than two electrons. this hydrogen is part of a covalent bond (sharing two electrons). a double bond here would cause hydrogen to share four electrons with phosphorus.