State of Matter: Gases-MCQS Part II
Temperature & Conversions
- What is 25ยฐC in Kelvin?
A. 298 K
B. 273 K
C. 250 K
D. 300 K
Answer:ย A - The Kelvin temperature of a gas is directly used in gas laws because:
A. It avoids negative values
B. It correlates with kinetic energy
C. It simplifies calculations
D. All of the above
Answer:ย D
States of Matter & Volume
- Which state of matter has no definite volume?
A. Solid
B. Liquid
C. Gas
D. Plasma
Answer:ย C - 1 cmยณ is equivalent to:
A. 1 L
B. 1 mL
C. 10 mL
D. 0.1 L
Answer:ย B - Gas volume depends on:
A. Container size
B. Temperature
C. Pressure
D. All of the above
Answer:ย D
Pressure & Units
- Pressure is defined as:
A. Force ร Area
B. Force/Area
C. Volume/Temperature
D. Mass/Volume
Answer:ย B - 1 atm is equal to:
A. 760 mmHg
B. 700 torr
C. 100 kPa
D. 1 Pa
Answer:ย A - If a gasโs pressure increases, its volume (at constant temperature):
A. Increases
B. Decreases
C. Remains constant
D. Fluctuates
Answer:ย B
Manometers
- In a mercury manometer, if the gas pressure is greater than atmospheric pressure, the Hg level:
A. Rises on the gas side
B. Drops on the gas side
C. Remains equal
D. None of the above
Answer:ย B - A gas pressure measured as 800 mmHg corresponds to:
A. 1 atm + 40 mmHg
B. 2 atm
C. 0.5 atm
D. 1.05 atm
Answer:ย D
Ideal Gas Assumptions
- Ideal gases assume particles have:
A. Significant volume
B. Strong intermolecular forces
C. No intermolecular forces
D. Fixed positions
Answer:ย C - The assumption that gas particles have negligible volume is most valid at:
A. High pressure
B. Low pressure
C. High temperature
D. Low temperature
Answer:ย B - Average kinetic energy of gas particles depends on:
A. Pressure
B. Temperature
C. Volume
D. Number of moles
Answer:ย B
Gas Laws
- Boyleโs Law states:
A.ย PโTPโT
B.ย VโTVโT
C.ย Pโ1VPโV1โ
D.ย VโnVโn
Answer:ย C - Charlesโs Law relates:
A. Pressure and Volume
B. Volume and Temperature
C. Pressure and Temperature
D. Volume and Moles
Answer:ย B - Avogadroโs Law states that volume is proportional to:
A. Pressure
B. Moles of gas
C. Temperature
D. Density
Answer:ย B - Combined Gas Law formula is:
A.ย P1V1T1=P2V2T2T1โP1โV1โโ=T2โP2โV2โโ
B.ย PV=nRTPV=nRT
C.ย P1V1=P2V2P1โV1โ=P2โV2โ
D.ย VโTVโT
Answer:ย A
Ideal Gas Law
- The value ofย RRย is:
A. 8.314 J/molยทK
B. 0.0821 Lยทatm/molยทK
C. 62.36 Lยทtorr/molยทK
D. All of the above
Answer:ย D - At STP, 1 mole of gas occupies:
A. 22.4 L
B. 24 L
C. 20 L
D. 25 L
Answer:ย A - A gas at 2 atm, 5 L, 300 K has how many moles? (R=0.0821R=0.0821)
A. 0.4 mol
B. 2.4 mol
C. 4.0 mol
D. 0.2 mol
Answer:ย A
Gas Density
- Density of a gas is calculated by:
A.ย massvolumevolumemassโ
B.ย Pรmolarย massRTRTPรmolarย massโ
C. Both A and B
D.ย nVVnโ
Answer:ย C - A gas with molar mass 32 g/mol at 1 atm and 273 K has a density of:
A. 1.43 g/L
B. 0.089 g/L
C. 32 g/L
D. 22.4 g/L
Answer:ย A
Daltonโs Law
- Total pressure in a container is the sum of:
A. Partial pressures
B. Mole fractions
C. Kinetic energies
D. Volumes
Answer:ย A - Ifย Ptotal=10Ptotalโ=10ย atm andย moleย fractionย ofย CO2=0.2moleย fractionย ofย CO2โ=0.2,ย PCO2PCO2โโย is:
A. 2 atm
B. 5 atm
C. 0.5 atm
D. 10 atm
Answer:ย A
Grahamโs Law
- Effusion rate is inversely proportional to:
A. Temperature
B. Square root of molar mass
C. Pressure
D. Volume
Answer:ย B - He (4 g/mol) effuses ______ times faster than Oโ (32 g/mol):
A. 8
B. 2.8
C. 4
D. 16
Answer:ย B
Advanced Applications
- Heating a gas in a fixed container increases:
A. Volume
B. Pressure
C. Moles
D. Density
Answer:ย B - In the reactionย A+BโABA+BโAB, total moles decrease. If initial pressure was 1.5 atm, final pressure is:
A. Higher
B. Lower
C. Same
D. Depends on temperature
Answer:ย B
Kinetic Molecular Theory
- Collisions between ideal gas particles are:
A. Inelastic
B. Perfectly elastic
C. Endothermic
D. Exothermic
Answer:ย B - At the same temperature, He and Ne have the same:
A. Speed
B. Kinetic energy
C. Mass
D. Volume
Answer:ย B
