Question

For many purposes we can treat ammonia (NH) as an ideal gas at temperatures above its boiling point of -33.C. Suppose the temperature of a sample of ammonia gas is raised from -21.0°C to 23.0°C, and at the same time the pressure is changed. If the initial pressure was 4.6 atm and the volume decreased by 50.0%, what is the final pressure? Round your answer to 2 significant digits. atm OP x 5 ?

Answer 1

The final pressure of the ammonia gas, given that the the volume decreased by 50.0%, is 11 atm

How to calculate the final pressure f the ammonia gas?

To solve this question in the most simplified way, we shall begin by listing out the given data from the question. This is shown below:

• Initial temperature of ammonia gas (T₁) = -21 °C = -21 + 273 = 252 K
• Final temperature of ammonia gas (T₂) = 23 °C = 23 + 273 = 296 K
• Initial volume of ammonia gas (V₁) = V
• Initial pressure of ammonia gas (P₁) = 4.6 atm
• Final volume of ammonia gas (V₂) = 50% of V₁ = 0.5V
• Final pressure of ammonia gas (P₂) = ?

The final pressure of the ammonia gas can be calculated as shown below:

`(P_1V_1)/(T_1) = (P_2V_2)/(T_2)\\\\(4.6\ *\ V)/(252) = (P_2\ *\ 0.5V)/(296)\\\\252\ *\ P_2\ *\ 0.5V = 4.6\ *\ V\ *\ 296\\\\P_2 = (4.6\ *\ V\ *\ 296)/(252\ *\ 0.5V) \\\\P_2 = 11\ atm`

Thus, the final pressure is 11 atm

Answer 2

In homeothermic (“warm-blooded”) animals, body temperature is carefully

regulated. The hypothalamus, located in the brain, acts as the master ther-

mostat to keep body temperature constant to within a fraction of a degree

Celsius in a healthy animal. If the body temperature starts to deviate much

from the desired constant level, the hypothalamus causes changes in blood

flow and initiates other processes, such as shivering or perspiration, to bring

the temperature back to normal. What evolutionary advantage does a con-

stant body temperature give the homeotherms (e.g., birds and mammals)

over the poikilotherms (e.g., reptiles and insects), whose body temperatures

are not kept constant? What are the disadvantages?

Explanation: Basic chemical understanding as revealed upwards