Answer:
The empirical formula is PCl3
Explanation:
Mass of P is 30.97 g, thus 1.523 g of P equivalent to 0.05 moles of P
Mass of Cl is 35.45 g, thus 5.228 g of Cl equivalent to 0.15 moles of Cl
Therefore moles of P : moles of Cl = 0.05:0.15 = 1:3
Therefore the empirical formula, PCl3
Explanation:
A substance burning in the presence of oxygen and leads to the formation of heat and light is called combustion.
Some important points about combustion are as follows:
- Fuel should be present for burning.
- Air should be present for the supply of oxygen.
- There should be heat (or ignition temperature) to initiate the chemical reaction.
The heat from the hotter water will go into the colder water untl equilibrium is reached. Equilibrium is same temperature!
Now, the heat is proportional to the mass, the specific heat and the temperature difference. The specific heat does not matter since all is water, it will cancel out:
m_1 * c_H20 * ( T_final - T_1 ) = -m_2 * c_H20 * ( T_final - T_2)
Notice the minus, because one wins the heat of the one who loses it. In this way both sides have the same sign:
m_1*(T_final - T_1)=-m_2*(T_final-T_2), or after some simple algebra:
T_final = (m_1 * T_1 + m_2 * T_2 )/(m_1+m_2),
which looks like an arithmetic mean, and one could have gone for this, but the above shows all the work. Notice that if T_1=T_2, T_final=T_1 always, which makes sense.
Now you can convert volume to mass with the density, but since mass = density*volume and it is all water, the density will cancel out and you can work with volumes. If you prefer just say: 120 ml->120 g , etc ...
T_final = (120*95+320*25)/(320+120)=44.0909 degrees Celsius, or ~ 44.09 degrees with two decimal precision as your statement (beware of precision always!).
