The relation between the volume and the temperature of the gas is given by Charles's law. The final temperature of the gas at 0.75 liters is -193.8°C.
<h3>What is Charles's law?</h3>
Charles's law was derived from the ideal gas equation and is used to state the relationship between the temperature and the volume of the gas. With a decrease in volume the temperature decreases.
If the pressure is kept constant then with an increase in temperature the volume of the gas expands. The law is given as,
V₁ ÷ T₁ = V₂ ÷ T₂
Given,
Initial volume (V₁) = 2.80 L
Initial temperature (T₁) = 23 °C = 296.15 K
Final volume (V₂) = 0.75 L
Final temperature = T₂
Substituting the values above as:
T₂ = (V₂ × T₁) ÷ V₁
= 0.75 × 296.15 ÷ 2.80
= 79.325 K
Kelvin is converted as, 79.325K − 273.15 = -193.8°C
Therefore, the final temperature is -193.8°C.
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Answer:
Option D. 230 J
Explanation:
We'll begin by calculating the temperature change of the iron. This can be obtained as follow:
Initial temperature (T₁) = 50 °C
Final temperature (T₂) = 75 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = 75 – 50
ΔT = 25 °C
Thus, the temperature change of the iron is 25 °C.
Finally, we shall determine the amount of heat energy used. This can be obtained as follow:
Mass (M) = 20 g
Change in temperature (ΔT) = 25 °C
Specific heat capacity (C) = 0.46 J/gºC
Heat (Q) =?
Q = MCΔT
Q = 20 × 0.46 × 25
Q = 230 J
Thus, the amount of heat used was 230 J
The gram formula mass of P2O5 is 31*2 + 16*5 =142. The mole number of P2O5 is 0.380/142=0.00268 mol. There is 7 atom in one P2O5 molecule. And there is 6.02 * 10^23 molecule per mol. So the answer is 1.13*10^22 atoms.
