Physical Chemistry Answers

Three 1.0 liter flasks are filled with hydrogen, oxygen and Neon, respectively, at STP. Which of the following statements is true?
The density of each gas is the same.
The velocity of the gas molecules is the same in each flask.
Each flask has the same number of gas molecules.
There are twice as many oxygen and hydrogen molecules as Ne atoms.
12 A real gas most closely approaches the behavior of an ideal gas under conditions of:
high P and low T
low P and high T
low P and T
high P and T
13 ______________ is used for measuring the viscosity of a substance.
Potentiometer
Ostwald viscometer
Calorimeter
None of the above
14 ______________ is used to measure the strength of an acid or base.
PH meter
Potentiometer
PH scale
Acidometer
15 The S.I. unit for frequency is __________.
Hertz
Ohms
Freq
Joule
16 The formation of a solid from a solution is called __________
Precipitation
Sublimation
Crystallization
Distillation

According to the kinetic theory of gases, a gas can be compressed much more than a liquid or solid because
a gas is composed of very small particles.
the particles of a gas are very far apart.
gas particles move rapidly.
gas particles do not attract or repel one another.
6 For a gas, which pair of variables are inversely proportional to each other (if all other conditions remain constant)?
P, T
P, V
V, T
n, V
7 Which measurement describes the pressure of a gas?
315 K
1.2 g/L
725 mm Hg
2.5 L
8 Electrical resistance is measured in _____________.
Hertz
Rest
Joule
Ohms
9 The process of separating a pure solid from a solution is known as _______________.
Distillation
Sublimation
Fractionation
Crystallization
10 Standard temperature and pressure refers to:
0 atm and 273 K
1 atm and 273 K
101.325 kPa and 0 K
more than one of the above

The S.I unit of energy is __________.
Joule
Kilo
power
meter
2 Which of these is correct?
0.35 kg
0.35 Kg
0.35kg
0.35KG
3 An ideal gas differs from a real gas in that the molecules of an ideal gas __________.
have an average molecular mass
have no kinetic energy
have a molecular weight of zero
have no attraction for one another
4 An ideal gas is contained in a volume V at temperature T. If the volume is doubled at constant pressure, the temperature will be _____________.
unchanged
halved
doubled
None of the above

Which one following molecule will have different value of molar enthalpy of formation, one calculate using bond energy concept and other measured calorimetrically
1) C2H6
2) but-1,3-diene
3) 1, 4-cyclohexadiene
4) N2O

If 50 mL 0.1 M NaOH and 100 mL 0.1 M CH3COOH is mixed to make a buffer, what is the pH of this buffer? ka=1.8*10^-5. If 100 mL 0.6 M more NaOH is mixed with this buffer solution, what is the new pH?

If 150 mL 0.1 M NaOH and 100 mL 0.1 M CH3COOH is mixed to make a buffer, what is the pH of this buffer? ka=1.8*10^-5

10 mL 0.15 M NaOH and 10 mL 0.1 M HCl are mixed to make a buffer. ka=1.8*10^-5 . what is the pH of this buffer?

500 mL and 0.3 atm of N2 and 450 mL And 0.5 atm of H2 are mixed in a 1L pot.what is their partial pressure?
why we will use the final volume after mixing 1L? if we mix both solution in this pot the total volume should be 500+450=950 mL. so why we use 1 L?

For the reaction A+3B=2C+D, initial mole of A is twice that of B. If at equilibrium moles of B and C are equal, then percentage of B reacted is ?

In a closed system A(s)= 2B(g)+3C(g) if the partial pressure of C is doubled then partial pressure of B will be?