Question

Lindsey is warming up a piece of lead for a calorimetry experiment. She has found the mass of her piece of lead to be 75 grams and its initial temperature is 40 degrees Celsius. Lindsey needs the lead to be at 80 degrees Celsius for her experiment. How much heat must the lead absorb so that Lindsey can do her experiment? Please round your answer to one digit after the decimal point. Include proper units (abbreviated) and the substance formula.

Answer 1

Answer

384 J

Explanation

Given:

The mass of her lead, m = 75 grams

The initial temperature, T₁ = 40 °C

The temperature needed for her experiment is the final temperature, T₂ = 80 °C

The specific heat of lead, c = 0.128 J/g°C

What to find:

The heat that the lead must absorb so that Lindsey can do her experiment.

Step-by-step solution:

The heat, Q that the lead must absorb so that Lindsey can do her experiment can be calculated using;

$Q=mc\Delta T$

But ΔT = Final temperature - Initial temperature

ΔT = T₂ - T₁

ΔT = 80 °C - 40 °C

ΔT = 40 °C

Therefore, putting m as 75 g, c as 0.128 J/g°C, and ΔT = 80 °C into the formula above, we have

$\begin{gathered} Q=75g\times0.128J\text{/}g°C\times40°C \\ \\ Q=384\text{ }J \end{gathered}$

Therefore, the heat that the lead must absorb so that Lindsey can do her experiment is 384 J