Answer : The total pressure in the flask is 1.86 atm.
Explanation :
First we have to calculate the pressure of
gas.
Using ideal gas equation :
![PV=nRT\\\\P_{CO_2}=\frac{w}{M}\frac{RT}{V}](https://tex.z-dn.net/?f=PV%3DnRT%5C%5C%5C%5CP_%7BCO_2%7D%3D%5Cfrac%7Bw%7D%7BM%7D%5Cfrac%7BRT%7D%7BV%7D)
where,
P = Pressure of
gas = ?
V = Volume of
gas = 765 mL = 0.765 L (1 L = 1000 mL)
n = number of moles
w = mass of
gas = 1.25 g
M = molar mass of
gas = 44 g/mol
R = Gas constant = ![0.0821L.atm/mol.K](https://tex.z-dn.net/?f=0.0821L.atm%2Fmol.K)
T = Temperature of
gas = ![25.0^oC=273+25.0=298K](https://tex.z-dn.net/?f=25.0%5EoC%3D273%2B25.0%3D298K)
Putting values in above equation, we get:
![P_{CO_2}=\frac{w}{M}\frac{RT}{V}](https://tex.z-dn.net/?f=P_%7BCO_2%7D%3D%5Cfrac%7Bw%7D%7BM%7D%5Cfrac%7BRT%7D%7BV%7D)
![P_{CO_2}=\frac{1.25g}{44g/mol}\frac{(0.0821L.atm/mol.K)\times 298K}{0.765L}=0.909atm](https://tex.z-dn.net/?f=P_%7BCO_2%7D%3D%5Cfrac%7B1.25g%7D%7B44g%2Fmol%7D%5Cfrac%7B%280.0821L.atm%2Fmol.K%29%5Ctimes%20298K%7D%7B0.765L%7D%3D0.909atm)
Now we have to calculate the total pressure in the flask.
![P_T=P_{N_2}+P_{CO_2}](https://tex.z-dn.net/?f=P_T%3DP_%7BN_2%7D%2BP_%7BCO_2%7D)
Given :
![P_{CO_2}=0.909atm](https://tex.z-dn.net/?f=P_%7BCO_2%7D%3D0.909atm)
![P_{N_2}=725mmHg=\frac{725}{760}=0.954atm](https://tex.z-dn.net/?f=P_%7BN_2%7D%3D725mmHg%3D%5Cfrac%7B725%7D%7B760%7D%3D0.954atm)
conversion used : (1 atm = 760 mmHg)
Now put all the given values in the above expression, we get:
![P_T=0.954atm+0.909atm=1.86atm](https://tex.z-dn.net/?f=P_T%3D0.954atm%2B0.909atm%3D1.86atm)
Therefore, the total pressure in the flask is 1.86 atm.
Answer:
2.1 x 10^6 J
Explanation:
Long story short, just think of the units of every question and then think again which unit needs to be cancelled out inorder for you to get the one which is asked.
the formula to calculate heat energy is Q = mcT
T - change in temperature
m - mass of substance
c - specific heat capacity of substance
the change in temperature is already given but you will need to change it to kelvin inorder for it to get cancelled out with the unit under specific heat capacity which is J/k gram. Tk = Tc + 273 = 3.32 + 273.15 = 276.47K
now keep in mind that c varies from substance to substance.
in this case it is 4.18J/k.g for water.
you will also need to convert the mass from kilograms to grams so it can cancel out as well. so now let's multiply 1.82 kg by a 1000 so that we can convert it to grams. which is equivalent to 1820g
now it's all set...let's substitute the values we dag out in the Heat formula Q = mcT
=1820g x 4.18Jk.g x 276.47K = 2.1 x 10^6J
so this is out final answer for heat required to raise the temperature of water by the particularly given quantity.
peace to you.
Aluminum and copper because all of them have advantages and disadvantages over iron alloys.