1. When using the equation P1/T1= P2/T2to relate temperature and pressure of a gas, what must be held constant?2.A sample of gas is held in a capped flask. At 25 °C the pressure is 693 mmHg. What is the pressure of the gas at 37 °C?3.If the heat of vaporization of water is 40.7 kJ/mol, how much energy is required to vaporize 5.0 g of liquid water at 100 °C?4.Would you expect most of the components in a perfume to have a low or high vapor pressure? Explain

Explanation:

1.

P1/T1 = P2/T2

Charles' law states that the pressure of a gas on its containing vessel must be directly proportional to the absolute temperature at constant volume STP.

2.

Using P1/T1 = P2/T2

T1 = 25 °C

= 273 + 25

= 298 K

P1 = 693 mmHg

T2 = 37 °C

= 273 + 37

= 310 K

P2 = (693 * 310)/298

= 720.9 mmHg.

3.

q = n * Hvap

Where,

q = heat required

n = number of moles

Hvap = heat of vapourisation

Molar mass of H2O = (1*2) + 16

= 18 g/mol

Number of moles = mass/molar mass

= 5/18

= 0.28 mol.

q = 0.28 * 40.7

= 11.3 kJ.

4.

Volatility is defined as a property of a substance which describes how readily a substance vaporizes. At a particular temperature and pressure, a substance with high volatility (high vapour pressure) is more likely to exist as a vapor, while a substance with low volatility (low vapour pressure) is more likely to be a liquid or solid.

Most perfume components exist individually as gas so they have high vapour pressure.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

a boiling water reactor does not boil the water. a pressurized water reactor boils the water faster. a pressurized water reactor is heated directly by the core. a pressurized water reactor does not use fission.