Quick Review Flashcards - Click to flip and test your knowledge!
Question
How does the intermolecular space in gases compare to that in solids?
Answer
Intermolecular space is maximum in gases and minimum in solids.
Question
What is the relative strength of the force of attraction between particles in a liquid compared to a solid?
Answer
The force of attraction is less in liquids than in solids.
Question
In which state of matter is the force of attraction between particles considered negligible?
Answer
Gases.
Question
How do solids and liquids differ regarding the direction of the pressure they exert?
Answer
Solids and liquids exert pressure only partially downwards, whereas gases exert pressure on all walls of the container.
Question
Which state of matter is characterised by having the least number of particles per unit area?
Answer
Gases.
Question
What is the miscibility characteristic of particles in a gaseous state?
Answer
Gases have high miscibility as particles rapidly diffuse with particles of other gases.
Question
In the context of gas laws, what does temperature indicate at a molecular level?
Answer
Temperature is an indicator of the average kinetic energy possessed by a molecule.
Question
Define 'Pressure' in the context of gas behaviour.
Answer
Pressure is the average force exerted by gas molecules on the walls of a container per unit area.
Question
What is the volume of a gas defined as?
Answer
The space occupied by a fixed mass of gas.
Question
Convert $0^{\circ}C$ to the Kelvin scale.
Answer
$273 K$.
Question
What is the value of $1$ Atmosphere in millimetres of Mercury ($mm$ $Hg$)?
Answer
$760 mm$ $Hg$.
Question
How many cubic centimetres ($cm^3$) are equivalent to $1$ litre?
Answer
$1000 cm^3$.
Question
State Boyle's Law regarding the relationship between volume ($V$) and pressure ($P$).
Answer
At constant temperature, the volume of a given mass of dry gas is inversely proportional to its pressure ($V \propto \frac{1}{P}$).
Question
State Charles' Law regarding the relationship between volume ($V$) and absolute temperature ($T$).
Answer
At constant pressure, the volume of a given mass of dry gas is directly proportional to its absolute temperature ($V \propto T$).
Question
What is the mathematical expression for the Gas Equation derived from Boyle's and Charles' Laws?
Answer
$\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2} = K$.
Question
What are the standard values for temperature and pressure at S.T.P.?
Answer
$273 K$ ($0^{\circ}C$) and $760 mm$ $Hg$ ($1$ atmosphere).
Question
State Gay Lussac's Law of combining volumes of gases.
Answer
When gases react, they do so in volumes which bear a simple whole number ratio to one another and to the gaseous products, provided temperature and pressure remain constant.
Question
According to Gay Lussac's Law, what is the volume ratio of Hydrogen to Oxygen to Steam in the reaction $2H_2 + O_2 \rightarrow 2H_2O$?
Answer
$2 : 1 : 2$.
Question
In the formation of Ammonia ($N_2 + 3H_2 \rightarrow 2NH_3$), what is the volume ratio of Nitrogen to Hydrogen?
Answer
$1 : 3$.
Question
According to Avogadro's Law, what is true of equal volumes of all gases under the same conditions of temperature and pressure?
Answer
They contain the same number of molecules.
Question
How did Avogadro distinguish an atom from a molecule?
Answer
An atom is the smallest particle that takes part in a chemical reaction, while a molecule is the smallest particle that can exist by itself.
Question
Term: Atomicity
Answer
Definition: The number of atoms present in one molecule of an element.
Question
If $1$ litre of oxygen contains '$n$' molecules, how many molecules are in $1$ litre of nitrogen at the same temperature and pressure?
Answer
'$n$' molecules.
Question
Define Relative Atomic Mass ($RAM$).
Answer
The number of times one atom of an element is heavier than $\frac{1}{12}$ the mass of an atom of carbon [$C^{12}$].
Question
What is the formula for calculating Relative Molecular Mass ($RMM$)?
Answer
$RMM = \frac{\text{Mass of one molecule of the substance}}{\frac{1}{12} \text{ Mass of an atom of carbon } [C^{12}]}$.
Question
Define 'Gram Atomic Mass'.
Answer
The relative atomic mass of an element expressed in grams.
Question
What is the Gram Molecular Mass of Oxygen ($O_2$) if its relative molecular mass is $32$?
Answer
$32 g$.
Question
Why are atomic weights usually not whole numbers?
Answer
Natural elements are mixtures of two or more isotopes with constant composition, making the weight a weighted average.
Question
What is the standard unit used to express atomic weights?
Answer
Atomic mass unit ($a.m.u.$).
Question
Define a 'Mole' in terms of Carbon-12.
Answer
The amount of substance containing the same number of units as there are atoms in $12.000 g$ of carbon-12.
Question
What is the numerical value of Avogadro's Number?
Answer
$6.023 \times 10^{23}$.
Question
How many atoms are present in $1$ mole of Calcium atoms?
Answer
$6.023 \times 10^{23}$ atoms.
Question
What is the mass of $1$ mole of water ($H_2O$) molecules?
Answer
$18 g$.
Question
What volume does $1$ mole of any gas occupy at S.T.P.?
Answer
$22.4$ litres (or $22.4 dm^3$).
Question
How many Oxygen atoms are in $1$ mole of Carbon dioxide ($CO_2$)?
Answer
$2 \times 6.023 \times 10^{23}$ atoms.
Question
Calculate the number of molecules in $1$ mole of Ammonia ($NH_3$).
Answer
$6.023 \times 10^{23}$ molecules.
Question
What is the total number of atoms in one molecule of Sulphuric acid ($H_2SO_4$)?
Answer
$7$ atoms.
Question
Define 'Vapour Density'.
Answer
The ratio of the mass of a certain volume of gas to the mass of the same volume of hydrogen under identical conditions.
Question
What is the mathematical relationship between Relative Molecular Mass and Vapour Density?
Answer
$\text{Molecular weight} = 2 \times \text{Vapour density}$.
Question
Term: Monoatomic element
Answer
Definition: Elements which have only one atom in their molecules, such as Helium or Neon.
Question
Which law explains Gay Lussac's Law by stating that equal volumes of gases contain equal numbers of molecules?
Answer
Avogadro's Law.
Question
Define 'Molar Volume'.
Answer
The volume occupied by $1$ gram molecular weight of a gas at S.T.P., which is $22.4$ litres.
Question
What is the formula for 'Gram Molecules'?
Answer
$\text{Gram molecules} = \frac{\text{Mass in grams of substance}}{\text{Relative molecular mass [Mol. Wt.]}}$.
Question
How many moles are in $7 g$ of Nitrogen gas ($N_2$)?
Answer
$0.25$ moles.
Question
Calculate the mass of $50 cm^3$ of Carbon monoxide ($CO$) at S.T.P. ($C=12, O=16$).
Answer
$0.0625 g$.
Question
What is the atomicity of a gas if $1 g$ of it occupies $11,200 cm^3$ at S.T.P. and its atomic weight is $1$?
Answer
$2$.
Question
Calculate the number of gram atoms in $8 g$ of Oxygen ($O=16$).
Answer
$0.5$ gram atoms.
Question
If a gas cylinder holds $50 g$ of Hydrogen, how many grams of gas A ($V.D. = 4$) would it hold under the same conditions?
Answer
$200 g$.
Question
If the Vapour Density of $CO_2$ is $22$, what is its Relative Molecular Mass?
Answer
$44$.
Question
In the reaction $2CO + O_2 \rightarrow 2CO_2$, if $450 cm^3$ of $CO$ reacts with $200 cm^3$ of $O_2$, which reactant is in excess?
Answer
Carbon monoxide ($CO$).
Question
How much $CO_2$ is formed when $200 cm^3$ of $O_2$ reacts completely with $400 cm^3$ of $CO$?
Answer
$400 cm^3$.
Question
According to the source, what is the weight of $1$ litre of Hydrogen gas at S.T.P.?
Answer
$0.09 g$.
Question
What is the relationship between '$1$ mole' and the number of particles it contains?
Answer
$1$ mole contains $6.023 \times 10^{23}$ particles (atoms, molecules, or ions).
Question
If $100 cc$ of gas A contains $Y$ molecules, how many molecules are in $50 cc$ of gas B at the same temperature and pressure?
Answer
$\frac{Y}{2}$ molecules.
Question
According to Avogadro's Law, the molecules of Oxygen gas ($O_2$) and Hydrogen gas ($H_2$) occupy _____ volume under the same conditions.
Answer
The same.
Question
Which isotope of carbon is used as the standard for atomic and molecular mass comparison?
Answer
Carbon-12 ($C^{12}$).
Question
Calculate the Relative Molecular Mass of Sulphuric acid ($H_2SO_4$) given $H=1, S=32, O=16$.
Answer
$98$.
Question
What is the volume occupied by $6.023 \times 10^{22}$ molecules of a gas at S.T.P.?
Answer
$2.24$ litres.
Question
How many Hydrogen atoms are present in $1$ mole of Sulphuric acid ($H_2SO_4$)?
Answer
$2 \times 6.023 \times 10^{23}$ atoms.
Question
In a mixture of $10 cm^3$ of $CO$ and $5 cm^3$ of $O_2$, what volume of $CO_2$ is produced upon ignition?
Answer
$10 cm^3$.