Class activity- Chapter 6 Name Dry ice is converted to a room temperature gas. q
ID: 2032486 • Letter: C
Question
Class activity- Chapter 6 Name Dry ice is converted to a room temperature gas. q for the roon is-435. what is the q for the dry ice? (-1 . 2. A chemical reaction produces 180J of heat and a gas which expands its container using 120 J. What is the ?? of the chemicals? Calculate the energy transferred when 518 g of PbO cools from 78°C to 50°C. (C-0.59J/(g K) 3. 4. 100 ml of 0.5M HCI was mixed with 100 ml of 0.5M NaOH in a coffee cup calorimeter The initial temperature of both solutions was 22.5 °C. After mixing the temperature of the solution was 25.86 °C. Calculate the ????. Assume the mixed solution has a density of 1.0 g/ml and a specific heat of 4.184J/g °C. The calorimeter has a heat capacity of 10J "CExplanation / Answer
Q1.
as there is no external sink or source,
heat lost by the room=heat gained by the dry ice
==>q for the dry ice=435 J
Q2.
using first law of thermodynamics,
heat supplied=change in internal energy+work done
==>180=120+change in internal energy
==>change in internal energy=180-120=60 J
Q3.
energy transferred=mass*specific heat*temperature difference
=518*0.59*(78-50)
=8557.4 J