. How much heat does it take to melt 2.5 kg of lead when it is at its melting point (m.p. = 327.5°C; Hf = 2.04 × 104 J/kg)?
6.2 × 101 J
8.2 × 103 J
5.1 × 104 J
1.7 × 107 J
I DONT WANNA GO DOWN IN THE TUBE STATION AT MIDNIGHT!
To find out how much heat it takes to melt 2.5 kg of lead at its melting point, we can use the equation:
Q = m * Hf
where Q is the heat required, m is the mass, and Hf is the heat of fusion.
Here, the mass (m) is given as 2.5 kg, and the heat of fusion (Hf) for lead is given as 2.04 × 10^4 J/kg.
Substituting the values into the equation:
Q = 2.5 kg * 2.04 × 10^4 J/kg
Now, we can calculate the value of Q:
Q = 5.1 × 10^4 J
Therefore, the correct answer is 5.1 × 10^4 J.