<u>We are given:</u>
P1 = 3 atm T1 = 623 K <em>(350 + 273)</em>
P2 = x atm T2 = 523 K <em>(250 + 273)</em>
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<u>Solving for x:</u>
From the idea gas equation:
PV = nRT
since number of moles (n) , Volume (V) and the Universal Gas constant(R) are constants;
P / T = k (where k is a constant)
the value of k will be the same for a gas with variable pressure and temperature and constant moles and volume
Hence, we can say that:
P1 / T1 = P2 / T2
3 / 623 = x / 523
x = 523 * 3 / 623
x = 2.5 atm (approx)
Therefore, the final pressure is 2.5 atm
Radioactive decay => C = Co { e ^ (- kt) |
Data:
Co = 2.00 mg
C = 0.25 mg
t = 4 hr 39 min
Time conversion: 4 hr 39 min = 4.65 hr
1) Replace the data in the equation to find k
C = Co { e ^ (-kt) } => C / Co = e ^ (-kt) => -kt = ln { C / Co} => kt = ln {Co / C}
=> k = ln {Co / C} / t = ln {2.00mg / 0.25mg} / 4.65 hr = 0.44719
2) Use C / Co = 1/2 to find the hallf-life
C / Co = e ^ (-kt) => -kt = ln (C / Co)
=> -kt = ln (1/2) => kt = ln(2) => t = ln (2) / k
t = ln(2) / 0.44719 = 1.55 hr.
Answer: 1.55 hr
Answer:
coordination number
Explanation:
Coordination number -
In a crystal lattice , the number of atoms that are surrounded to a particular atom , is referred to as the coordination number of the crystal.
In the field of crystallography and chemistry , it is also called the ligancy.
In coordination chemistry , the number of ligands attached to the central metal atom is also known as the coordination number of the coordination compound.
Hence, from the given statement of the question,
The correct term is coordination number.
Answer : The internal energy change is -2805.8 kJ/mol
Explanation :
First we have to calculate the heat gained by the calorimeter.
where,
q = heat gained = ?
c = specific heat = 
= final temperature = 
= initial temperature = 
Now put all the given values in the above formula, we get:
Now we have to calculate the enthalpy change during the reaction.
where,
= enthalpy change = ?
q = heat gained = 23.4 kJ
n = number of moles fructose = 
Therefore, the enthalpy change during the reaction is -2805.8 kJ/mole
Now we have to calculate the internal energy change for the combustion of 1.501 g of fructose.
Formula used :
or,
where,
= change in enthalpy = 
= change in internal energy = ?
= change in moles = 0 (from the reaction)
R = gas constant = 8.314 J/mol.K
T = temperature = 
Now put all the given values in the above formula, we get:
Therefore, the internal energy change is -2805.8 kJ/mol
