Answer : The final temperature of the mixture is ![29.6^oC](https://tex.z-dn.net/?f=29.6%5EoC)
Explanation :
In this problem we assumed that heat given by the hot body is equal to the heat taken by the cold body.
![q_1=-q_2](https://tex.z-dn.net/?f=q_1%3D-q_2)
![m_1\times c_1\times (T_f-T_1)=-m_2\times c_2\times (T_f-T_2)](https://tex.z-dn.net/?f=m_1%5Ctimes%20c_1%5Ctimes%20%28T_f-T_1%29%3D-m_2%5Ctimes%20c_2%5Ctimes%20%28T_f-T_2%29)
where,
= specific heat of iron = ![0.499J/g^oC](https://tex.z-dn.net/?f=0.499J%2Fg%5EoC)
= specific heat of water = ![4.18J/g^oC](https://tex.z-dn.net/?f=4.18J%2Fg%5EoC)
= mass of iron = 39.9 g
= mass of water = ![Density\times Volume=1g/mL\times 50.0mL=50.0g](https://tex.z-dn.net/?f=Density%5Ctimes%20Volume%3D1g%2FmL%5Ctimes%2050.0mL%3D50.0g)
= final temperature of mixture = ?
= initial temperature of iron = ![78.1^oC](https://tex.z-dn.net/?f=78.1%5EoC)
= initial temperature of water = ![25.0^oC](https://tex.z-dn.net/?f=25.0%5EoC)
Now put all the given values in the above formula, we get
![(39.9g)\times (0.499J/g^oC)\times (T_f-78.1)^oC=-(50.0g)\times 4.18J/g^oC\times (T_f-25.0)^oC](https://tex.z-dn.net/?f=%2839.9g%29%5Ctimes%20%280.499J%2Fg%5EoC%29%5Ctimes%20%28T_f-78.1%29%5EoC%3D-%2850.0g%29%5Ctimes%204.18J%2Fg%5EoC%5Ctimes%20%28T_f-25.0%29%5EoC)
![T_f=29.6^oC](https://tex.z-dn.net/?f=T_f%3D29.6%5EoC)
Therefore, the final temperature of the mixture is ![29.6^oC](https://tex.z-dn.net/?f=29.6%5EoC)
Potential energy and height; best guess;)
Answer:
50,849.25 Joules
Explanation:
The amount of heat, Q, required to raise the temperature of a body with mass, m, and specific heat capacity, c is given by:
Q = mcΔT, where ΔT represents the change in temperature.
In the case of the iron block:
m = 75 g
c = 0.449 J/g °C
ΔT = 1535 - 25 = 1510 °C
Therefore,
Q = 75 g x 0.449 J/g °C x 1510 °C
= 50,849.25 Joules
<em>Hence, </em><em>50,849.25 Joules </em><em> of heat must be added to a 75.0-g iron block with a specific heat of 0.449 J/g °C to increase its temperature from 25 °C to its melting temperature of 1535 °C</em>
Answer:
The answer is 6.25g.
Explanation:
First create your balanced equation. This will give you the stoich ratios needed to answer the question:
2C8H18 + 25O2 → 16CO2 + 18H2O
Remember, we need to work in terms of NUMBERS, but the question gives us MASS. Therefore the next step is to convert the mass of O2 into moles of O2 by dividing by the molar mass:
7.72 g / 16 g/mol = 0.482 mol
Now we can use the stoich ratio from the equation to determine how many moles of H2O are produced:
x mol H2O / 0.482 mol O2 = 18 H2O / 25 O2
x = 0.347 mol H2O
The question wants the mass of water, so convert moles back into mass by multiplying by the molar mass of water:
0.347 mol x 18 g/mol = 6.25g