A 34 g glass thermometer reads 21.6°C before it is placed in 135 mL of water. When the water and thermometer come to equilibrium, the thermometer reads 38.7°C. What was the original temperature of the water?
I need help on this please could someone please help out.Thank you!
Physics - bobpursley, Tuesday, April 24, 2012 at 5:53pm
the sum of heats gained is zero.
massglass*specheatglass*(21.6-38.7)+135*specheatwater*(Ti-38.6)=0
solve for Ti
Physics - Akbar, Tuesday, April 24, 2012 at 6:58pm
I got 15.43 degree Celsius but its wrong. I don't know why please help. Thank you!
To solve this problem, we can use the principle of heat exchange. The heat gained by the glass thermometer is equal to the heat lost by the water when they come to equilibrium. We can express this as an equation:
Heat gained by thermometer = Heat lost by water
The heat gained by the thermometer can be calculated using the specific heat capacity of glass, the mass of the thermometer, and the change in temperature. The heat lost by the water can be calculated using the specific heat capacity of water, the mass of water, and the change in temperature.
Let's label the original temperature of the water as "Ti".
Given:
Mass of the glass thermometer (m) = 34 g
Initial temperature of the thermometer (T_initial) = 21.6°C
Final temperature of the thermometer (T_final) = 38.7°C
Mass of water (m_water) = 135 mL = 135 g (since 1 mL of water has a mass of 1 g)
Specific heat capacity of glass (C_glass) = ?
Specific heat capacity of water (C_water) = 4.184 J/g°C (this is a standard value)
Using the equation mentioned earlier, we can write:
(m * C_glass * (T_initial - T_final)) + (m_water * C_water * (Ti - T_final)) = 0
Plugging in the known values:
(34 g * C_glass * (21.6°C - 38.7°C)) + (135 g * 4.184 J/g°C * (Ti - 38.7°C)) = 0
Solving this equation for Ti will give us the original temperature of the water.
You mentioned that you got an answer of 15.43°C, but it was incorrect. Here are a few things to double-check:
- Make sure you have the correct values for m, T_initial, T_final, and m_water.
- Double-check the value you used for the specific heat capacity of water (C_water). It should be 4.184 J/g°C.
- Check your calculations to ensure you didn't make any arithmetic errors.
If you recheck these steps and still can't figure out the problem, please let me know, and I can help you further.