how much heat is required to melt completely 20g ice at 0° C to water at 0°C?
Answers
Answer:
The energy to convert 20 g of ice at 0 degree Celsius to 20 g of water at 0 degree Celsius is;
E
m
=
m
L
f
Here
E
m
is the energy for melting the ice into water, m =20 g is the mass of the ice (water) and
L
f
=
80
cal/g
is the latent heat of fusion of water.
Thus,
E
m
=
20
g
×
80
c
a
l
/
g
E
m
=
1600
c
a
l
=
1600
×
4.184
J
E
m
=
6694
J
From 0 degree to 50 degree Celsius water, we need the heat energy of
Q
w
Q
w
=
c
w
m
Δ
T
Q
w
=
4.18
J/g
⋅
C
×
20
g
×
50
∘
Q
w
=
4180
J
Here,
c
w
=
4.18
J/g
⋅
C
is the heat capacity of water,
Δ
T
=
50
∘
is the temperature change.
Thus, the energy required to melt 20 g of ice and heat it to 50 degree Celsius is;
Q
=
E
m
+
Q
w
Q
=
6694
+
4180
Q
=
10874
J
Answer:
Heat for fusion is defined as the energy required to melt 1.0 kg of a substance from solid to liquid. It is expressed as follows;
We are given:
Mass of the ice is
20.0 - 0.020 kg ,Latent heat of fusion is L f 80 kal/kg