Question

A 300 g glass thermometer initially at 23 ◦C is put into 236 cm3 of hot water at 87 ◦C. Find the final temperature of the thermometer, assuming no heat flows to the surroundings. The specific heat of glass is 0.2 cal/g · ◦ C and of water 1 cal/g · ◦ C.

Answer 1

`74^(\circ) C`

Step-by-step explanation:

We are given that

Mass of glass,
`m=300 g`

`T_1=23^(\circ)`

Volume,
`V=236cm^3`

Mass of water=
`density* volume=1* 236=236 g`

Density of water=
`1g/cm^3`

Temperature of hot water,
`T=87^(\circ)`

Specific heat of glass,
`C_g=0.2cal/g^(\circ)C`

Specific heat of water,
`C_w=1 cal/g^(\circ)C`

`Q_(glass)=m_gC_g(T_f-T_1)=300* 0.2(T_f-23)`

`Q_(water)=m_wC_w(T_f-T)=236* 1(T_f-87)`

`Q_(glass)+Q_(water)=0`

`300* 0.2(T_f-23)+236* 1(T_f-87)`

`60T_f-1380+236T_f-20532=0`

`296T_f=20532+1380=21912`

`T_f=(21912)/(296)=74^(\circ) C`