Question

Which of the following substances would show the smallest temperature change upon absorbing 2.35 kJ of heat? (MTS 2/10/2018) 27 g Fe ; cFe = 0.449 J/goC 27 g H2O ; cH2O = 4.18 J/goC 27 g ethanol ; cethanol = 2.42 J/goC

Answer 1

Answer:

Water.

Explanation:

Hello,

Based on the formula:

$Q=mCp$Δ$T$

Solving for Δ$T$, we state that:

$Δ[tex]T$=\frac{Q}{mCp}[/tex]

Now, for each substance we get:

Δ$T_{Fe}=\frac{2350J}{27g*0.449J/g^0C} =193.85^0C$

Δ$T_{H_2O}=\frac{2350J}{27g*4.18J/g^0C} =20.82^0C$

Δ$T_{EtOH}=\frac{2350J}{27g*2.42J/g^0C} =35.97^0C$

We sum up that the water shows the smallest temperature change. This could be also stated by know that the iron has the highest heat capacity.

Best regards.