compare the boiling point of water at sea leavel to the boiling point in denver (altitude = 1 mile) Explain
1 answer:
You might be interested in
Answer:
2.104 L fuel
Explanation:
Given that:
Volume of water = 35 L = 35 × 10³ mL
initial temperature of water = 25.0 ° C
The amount of heat needed to boil water at this temperature can be calculated by using the formula:
where
specific heat of water c= 4.18 J/g° C
Also; Assume that the fuel has an average formula of C7 H16 and 15% of the heat generated from combustion goes to heat the water;
thus the heat of combustion can be determined via the expression
For heptane; the equation for its combustion reaction can be written as:
The standard enthalpies of the products and the reactants are:
Therefore; the standard enthalpy for this combustion reaction is:
This simply implies that the amount of heat released from 1 mol of C7H16 = 4466.1 kJ
However the number of moles of fuel required to burn heat released is:
Since number of moles = mass/molar mass
The mass of the fuel is:
Given that the density of the fuel is = 0.78 g/mL
and we know that :
density = mass/volume
therefore making volume the subject of the formula in order to determine the volume of the fuel ; we have
volume of the fuel = mass of the fuel / density of the fuel
volume of the fuel =
volume of the fuel = 2.104 L fuel
To answer this question, you need to know the concept of half-life, which is how a radioactive material decreases in mass over time.
The half life of U-235 is 703.8 million years. The first part of this problem is to find the scale factor. To do this, divide the time that has past by the half life, like this:
Now, take this scale factor and multiply it by the current mass, like this:
This number is what you add to the current mass to get the original mass. That is because the scale factor showed us that it was just over one half life. Since after one half life, the mass is cut in half, and this is over one half life, when we add to the original it will be a little over double. This equation illustrates the final addition:
I hope this helped you. Fell free to ask any further questions.
The half life of U-235 is 703.8 million years. The first part of this problem is to find the scale factor. To do this, divide the time that has past by the half life, like this:
Now, take this scale factor and multiply it by the current mass, like this:
This number is what you add to the current mass to get the original mass. That is because the scale factor showed us that it was just over one half life. Since after one half life, the mass is cut in half, and this is over one half life, when we add to the original it will be a little over double. This equation illustrates the final addition:
I hope this helped you. Fell free to ask any further questions.