Question

How much heat is required to raise the temperature of $150g$ of iron from ${20}^{\circ }C$ to ${25}^{\circ }C$?

• A. $350J$
• B. $345J$
• C. $360J$
• D. $330J$

Answer 1

Answer: (B)

$345J$

Given , $m=150g,{\theta }_1={20}^{0}C,{\theta }_2={25}^{0}C$

We have , specific heat of iron $c=0.46J/g{-}^{o}C$

Now , heat required to raise the temperature of iron is given by the definition of specific heat c ,

$Q=mc\Delta \theta =mc({\theta }_2-{\theta }_1)$

or $Q=150\times 0.46\times (25-20)=345J$