Answer:
120 g water is added.
Explanation:
The amount of heat energy given by a warm substance is the same as the amount of heat energy received by cooler substance in a closed system.
[tex]\boxed{Q_{received}=Q_{released}}[/tex], where [tex]\boxed{Q=m\cdot c\cdot \Delta T}[/tex]
Q = heat energy
m = mas
c = specific heat capacity
ΔT = temperature difference
Given:
m₁ = 300 g
T₁ = 30°C
T₂ = 100°C
T = 50°C
c = 4.2 J/g°C
Q₁ = Q₂
m₁ · c · (T - T₁) = m₂ · c · (T₂ - T)
300 × 4.2 × (50 - 30) = m₂ × 4.2 × (100 - 50)
300 × 20 = m₂ × 50
m₂ = 120 g
