Chapter U5.4, Problem 5E

(a)

Interpretation Introduction

Interpretation:

The heat transferred in the various trials is to be compared.

Concept introduction:

Whenever a hot body comes in contact with cold body, there is transfer of heat from hot body to cold body until temperature of both bodies become equal.

Heat transfer in a process can be calculated by formula:

  $\begin{array}{l}q=mc\Delta T\\ whereqisquantityofheatabsorbed\\ m=givenmass\\ \Delta T=riseintemperature\\ cisspecificheat\end{array}$

Answer to Problem 5E

Heat transferred to sample-I is equal to heat transferred from sample-II.

Explanation of Solution

Trial-I:

  $\begin{array}{l}c=1cal/g-°C\\ m_I=100g\\ m_{II}=100g\\ T_I=20°C\\ T_{II}=80°C\\ T_f=50°C\end{array}$

  $\begin{array}{c}\Delta T_I=50-20\\ =30°C\\ \Delta T_{II}=80-50\\ =30°C\end{array}$

  $\begin{array}{c}{q}_I=100\times 1\times 30\\ =3000cal\\ q_{II}=100\times 1\times 30\\ =3000cal\end{array}$

Trial-II:

  $\begin{array}{l}c=1cal/g-°C\\ m_I=100g\\ m_{II}=100g\\ T_I=20°C\\ T_{II}=70°C\\ T_f=45°C\end{array}$

  $\begin{array}{c}\Delta T_I=45-20\\ =25°C\\ \Delta T_{II}=70-45\\ =25°C\end{array}$

  $\begin{array}{c}{q}_I=100\times 1\times 25\\ =2500cal\\ q_{II}=100\times 1\times 25\\ =2500cal\end{array}$

Trial-III:

  $\begin{array}{l}c=1cal/g-°C\\ m_I=100g\\ m_{II}=300g\\ T_I=20°C\\ T_{II}=80°C\\ T_f=65°C\end{array}$

  $\begin{array}{c}\Delta T_I=65-20\\ =45°C\\ \Delta T_{II}=80-65\\ =15°C\end{array}$

  $\begin{array}{c}{q}_I=100\times 1\times 45\\ =4500cal\\ q_{II}=300\times 1\times 15\\ =4500cal\end{array}$

Trial-IV:

  $\begin{array}{l}c=1cal/g-°C\\ m_I=200g\\ m_{II}=100g\\ T_I=20°C\\ T_{II}=80°C\\ T_f=40°C\end{array}$

  $\begin{array}{c}\Delta T_I=40-20\\ =20°C\\ \Delta T_{II}=80-40\\ =40°C\end{array}$

  $\begin{array}{c}{q}_I=200\times 1\times 20\\ =4000cal\\ q_{II}=100\times 1\times 40\\ =4000cal\end{array}$

The given table is filled using the above formula:

	Sample-I Mass(g)	Sample-I Temperature (°C)	Sample-II Mass(g)	Sample-II Temperature (°C)	Final temperature (°C)	Heat transferred to sample-I (cal)	Heat transferred from sample-II (cal)
Trial- I	100	20	100	80	50	3000	3000
Trial- II	100	20	100	70	45	2500	2500
Trial- III	100	20	300	80	65	4500	4500
Trial- IV	200	20	100	80	40	4000	4000

(b)

Interpretation Introduction

Interpretation:

The effect of change in temperature on heat transferred in the various trials is to be compared.

Concept introduction:

Whenever a hot body comes in contact with cold body, there is transfer of heat from hot body to cold body until temperature of both bodies become equal.

Heat transfer in a process can be calculated by formula:

  $\begin{array}{l}q=mc\Delta T\\ whereqisquantityofheatabsorbed\\ m=givenmass\\ \Delta T=riseintemperature\\ cisspecificheat\end{array}$

Answer to Problem 5E

Heat transferred to sample-I is more when the change in temperature is more.

Explanation of Solution

	Sample-I Mass(g)	Sample-I Temperature (°C)	Sample-II Mass(g)	Sample-II Temperature (°C)	Final temperature (°C)	Heat transferred to sample-I (cal)	Heat transferred from sample-II (cal)
Trial- I	100	20	100	80	50	3000	3000
Trial- II	100	20	100	70	45	2500	2500
Trial- III	100	20	300	80	65	4500	4500
Trial- IV	200	20	100	80	40	4000	4000

The table shows heat transfer is maximum in which change temperature is more than rest trials keeping the mass fixed.

(c)

Interpretation Introduction

Interpretation:

The effect of mass on heat transferred in the various trials is to be compared.

Concept introduction:

Whenever a hot body comes in contact with cold body, there is transfer of heat from hot body to cold body until temperature of both bodies become equal.

Heat transfer in a process can be calculated by formula:

  $\begin{array}{l}q=mc\Delta T\\ whereqisquantityofheatabsorbed\\ m=givenmass\\ \Delta T=riseintemperature\\ cisspecificheat\end{array}$

Answer to Problem 5E

Heat transferred to sample-I is more when the change in temperature is more.

Explanation of Solution

	Sample-I Mass(g)	Sample-I Temperature (°C)	Sample-II Mass(g)	Sample-II Temperature (°C)	Final temperature (°C)	Heat transferred to sample-I (cal)	Heat transferred from sample-II (cal)
Trial- I	100	20	100	80	50	3000	3000
Trial- II	100	20	100	70	45	2500	2500
Trial- III	100	20	300	80	65	4500	4500
Trial- IV	200	20	100	80	40	4000	4000

Comparing the trials- I and IV, the table shows heat transfer is maximum in which mass of sample is more than other trial keeping temperature of samples fixed.