Question

round to two significant figures.
how much energy must be transferred to lower the temperature of 5.1 g of water from 201 k to 125 k
is energy absorbed or released?

Explanation:

Step1: Recall heat transfer formula

The formula for heat transfer is $q = mc\Delta T$, where $m$ is mass, $c$ is specific heat capacity of water ($4.184\ \text{J/g·K}$), and $\Delta T = T_{\text{final}} - T_{\text{initial}}$.

Step2: Calculate temperature change

$\Delta T = 125\ \text{K} - 201\ \text{K} = -76\ \text{K}$

Step3: Compute heat energy

$q = 5.1\ \text{g} \times 4.184\ \text{J/g·K} \times (-76\ \text{K}) \approx -1630\ \text{J}$

Step4: Round to 2 significant figures

$-1630\ \text{J} \approx -1600\ \text{J}$ (or $-1.6 \times 10^3\ \text{J}$). Negative sign means energy is released.

Answer:

Energy transferred: $-1.6 \times 10^3\ \text{J}$; Energy released.