266 MECHANICAL ENGINEERING PRINCIPLES
- A gas at a temperature of 27°C occupies
a volume of 5 m^3. The volume of the
same mass of gas at the same pressure
but at a temperature of 57°Cis:
(a) 10.56 m^3 (b) 5.50 m^3
(c) 4.55 m^3 (d) 2.37 m^3 - Which of the following statements is
false?
(a) An ideal gas is one that completely
obeys the gas laws.
(b) Isothermal changes are those that
occur at constant volume.
(c) The volume of a gas increases
when the temperature increases at
constant pressure.
(d) Changes that occur at constant pre-
ssure are called isobaric changes.
A gas has a volume of 0.4 m^3 when its pres-
sure is 250 kPa and its temperature is 400 K.
Use this data in questions 5 and 6. - The temperature when the pressure is
increased to 400 kPa and the volume is
increased to 0.8 m^3 is:
(a) 400 K (b) 80 K
(c) 1280 K (d) 320 K - The pressure when the temperature is
raised to 600 K and the volume is
reduced to 0.2 m^3 is:
(a) 187.5 kPa (b) 250 kPa
(c) 333.3 kPa (d) 750 kPa- A gas has a volume of 3 m^3 at a tem-
perature of 546 K and a pressure of
101.325 kPa. The volume it occupies at
STP is:
(a) 3 m^3 (b) 1.5 m^3 (c) 6 m^3- Which of the following statements is
false?
(a) A characteristic gas constant has
units of J/(kg K).(b) STP conditions are 273 K and
101.325 kPa.(c) All gases are ideal gases.(d) An ideal gas is one that obeys the
gas laws.A mass of 5 kg of air is pumped into a con-
tainer of volume 2.87 m^3. The characteristic
gas constant for air is 287 J/(kg K). Use this
data in questions 9 and 10.- The pressure when the temperature is
27 °Cis:
(a) 1.6 kPa (b) 6 kPa
(c) 150 kPa (d) 15 kPa- The temperature when the pressure is
200 kPa is:
(a) 400°C (b) 127°C
(c) 127 K (d) 283 K