A 100-g metal with a temperature of 97 oC is placed in a calorimeter with 75 mL water initially at 23 oC and the water rises to 27 oC. Calculate the total quantity of heat absorbed by the water in the calorimeter AND calculate the specific heat of the metal. Water has a specific heat of 4.18 J / g oC.
http://www.chemvideos.com/videos/24/calorimetry
Qwater = Qmetal
mcΔT(water) = mcΔT(metal)
m=mass c= specific heat ΔT= Ti - Tf (Initial temp - final temp)
Step 1 (75g)(4.18J/gDC)(27DC-23DC) = (100g)(c)(97DC-27DC)
Step 2 (313.5J/DC)(4DC) = (100g)(c)(70DC)
Step 3 (1254J) = (7000gDC)(c)
Step 4 0.179 J/gDC = c
Calculate the total quantity of heat absorbed by the water in the calorimeter = 1254J
Calculate the specific heat of the metal = 0.179 J/gDC
_______________________________________________________________________
Step 1) Just plug in the values from the question.
Step 2) Multiply (75g)(4.18J/gDC) which equals (313.5J/DC). The (g)s cancel out because multiplying is the opposite of division....(J/gDC) is division, so they cancel out. Then subtract (27DC-23DC) which equals (4DC).
On the other side of the problem subtract (97DC-27DC) which equals (70DC)
Step 3) Multiply (313.5J/DC)(4DC) which equals (1254J). The (DC) cancel out just like the (g)s from step 2.
On the right side multiply (1000g)(70DC) which gives you (7000gDC)
Step 4) Now (c) is the variable, so we have to isolate it. So Divide to get (7000gDC) to the left....(1254J) / (7000 gDC) equals (0.179J/gDC) .... The (gDC) is being divided into (J) so it comes out as (J/gDC) since nothing can cancel.
And your done.
Qwater = Qmetal
mcΔT(water) = mcΔT(metal)
m=mass c= specific heat ΔT= Ti - Tf (Initial temp - final temp)
Step 1 (75g)(4.18J/gDC)(27DC-23DC) = (100g)(c)(97DC-27DC)
Step 2 (313.5J/DC)(4DC) = (100g)(c)(70DC)
Step 3 (1254J) = (7000gDC)(c)
Step 4 0.179 J/gDC = c
Calculate the total quantity of heat absorbed by the water in the calorimeter = 1254J
Calculate the specific heat of the metal = 0.179 J/gDC
_______________________________________________________________________
Step 1) Just plug in the values from the question.
Step 2) Multiply (75g)(4.18J/gDC) which equals (313.5J/DC). The (g)s cancel out because multiplying is the opposite of division....(J/gDC) is division, so they cancel out. Then subtract (27DC-23DC) which equals (4DC).
On the other side of the problem subtract (97DC-27DC) which equals (70DC)
Step 3) Multiply (313.5J/DC)(4DC) which equals (1254J). The (DC) cancel out just like the (g)s from step 2.
On the right side multiply (1000g)(70DC) which gives you (7000gDC)
Step 4) Now (c) is the variable, so we have to isolate it. So Divide to get (7000gDC) to the left....(1254J) / (7000 gDC) equals (0.179J/gDC) .... The (gDC) is being divided into (J) so it comes out as (J/gDC) since nothing can cancel.
And your done.
- spam
- offensive
- disagree
- off topic
Like