Question

what is the change in heat of 11.2 grams of helium when its temperature decreases from 33°c to -29°c?
the specific heat of helium is 5.193 j/g°c.
round your answer to the correct number of significant figures.

joules
complete the sentence.
this process is because heat is by the helium as it cools.

Explanation:

Step1: Calculate the temperature change

$\Delta T=T_{final}-T_{initial}=- 29^{\circ}C - 33^{\circ}C=-62^{\circ}C$

Step2: Use the heat - change formula

The formula for heat change is $Q = mc\Delta T$, where $m = 11.2g$, $c = 5.193J/g^{\circ}C$, and $\Delta T=-62^{\circ}C$.
$Q=(11.2g)\times(5.193J/g^{\circ}C)\times(-62^{\circ}C)$
First, calculate $(11.2\times5.193)=58.1616$
Then, $Q = 58.1616\times(-62)J=-3606.0192J$
Rounding to three significant figures (since 11.2 has three significant figures), $Q=-3610J$

For the sentence:
When the temperature of a substance decreases, heat is released. An exothermic process is one in which heat is released.

Answer:

-3610 joules
This process is exothermic because heat is released by the helium as it cools.