What is the initial temperature of 50g of water that was raised to 50*C by the addition of 4.18kJ of heat energy? (2 sig fig)
1 answer:
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Answer:
The heat absorbed by the water is 228,948.48 J
Explanation:
Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.
In this way, between heat and temperature there is a direct proportional relationship (Two magnitudes are directly proportional when there is a constant so that when one of the magnitudes increases, the other also decreases; and the same happens when either of the two decreases .). The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat and the mass of the body. So, the equation that allows to calculate heat exchanges is:
Q = c * m * ΔT
where Q is the heat exchanged by a body of mass m, constituted by a substance of specific heat c and where ΔT is the variation in temperature.
In this case:
- c= 4.184
- m=855 g
- ΔT= Tfinal - Tinitial= 85 °C - 21°C= 64 °C
Replacing:
Q= 4.184 *855 g* 64 C
Solving:
Q= 228,948.48 J
<u><em>The heat absorbed by the water is 228,948.48 J</em></u>
Answer: Volume of CO2 is 89127 mL
Explanation: The reaction that takes place is: C2H2 + O2 --> CO2 + H2O
The amount of C2H2 that react allow us to predict the amount of CO2 that will be obtained
26g/1mol is molar mass of C2H2 and 2/4 is the molar relation between CO2 and C2H2 in this reaction. Canceling units, at the end mol of CO2 are obtained
Now with the moles of CO2 and the ideal gases equation is possible to calculate the volumen occupied by the gas.
PV = RnT where P: pressure, V: volume, R: ideal gas constant, n: moles and T: temperature expressed in K (add 273,15 to °C temperature: 37,4°C + 273,15 = 310,55K)
V= RnT/P
To express volume in mL multiply the L result by 1000 which equals 89127 mL