91Ó°ÊÓ

joule, a unit of work or energy in the International System of Units (SI); it is equivalent to the work done by a power of one newton acting through one meter.

given,

mass = $8.5g$

initial temperature = ${15}^{o}C$final temperature = ${36}^{0}C$

Specific heat of water $C_p$= $1\mathrm{Cal}/g^{∘}\mathrm{C}$

From the Specific heat formula,

$Q=m×\left(t_f−t_i\right)×C_p$

$$\begin{gathered} Q=8.5g×(36−15{)}^{∘}\mathrm{C}×1\mathrm{Cal}/g^{∘}\mathrm{C} \\ \mathrm{Q}=178.5\mathrm{cal} \end{gathered}$$

given,

mass =$25g$

initial temperature = ${86}^{o}C$final temperature = ${61}^{0}C$

Specific heat of water $=4.184J/g^{∘}\mathrm{C}$

from specific heat formula,

$\begin{array}{r}Q=m×\left(t_f−t_i\right)×C_p\\ Q=25g×(61−86{)}^{∘}\mathrm{C}×4.184\mathrm{J}/g^{∘}\mathrm{C}\end{array}$

$Q=-2615J$

given,

mass = $150g$

initial temperature =${15}^{o}C$final temperature =${77}^{o}C$

Specific heat of water $C_p=1\mathrm{Cal}/g^{∘}\mathrm{C}$

from the specific heat formula,

$Q=m×\left(t_f−t_i\right)×C_p$

$Q=150g×(77−15{)}^{∘}\mathrm{C}×1\mathrm{cal}/{\mathrm{g}}^{∘}\mathrm{C}$

$Q=9.3kcal$

given,

mass = $175g$

initial temperature = ${28}^{o}C$final temperature = ${188}^{o}C$

Specific heat of copper $C_p=0.385\mathrm{J}/g^{∘}\mathrm{C}$

From the specific heat formula,

$Q=m×\left(t_f−t_i\right)×C_p$

$Q=175g×(118−28{)}^{∘}\mathrm{C}×0.385\mathrm{J}/g^{∘}\mathrm{C}$

$Q=6.06375\mathrm{kJ}$