List of top Chemistry Questions asked in AP EAPCET

How many moles of $\mathrm{CO_2}$ are produced when 4 moles of $\mathrm{C_2H_6}$ (ethane) combust completely?
Given reaction: \[ 2 \mathrm{C_2H_6} + 7 \mathrm{O_2} \rightarrow 4 \mathrm{CO_2} + 6 \mathrm{H_2O} \]

The number of extensive and intensive properties in the list given below is respectively: % List - Density, enthalpy, mass, temperature, volume, pressure

1 mole of an ideal gas is allowed to expand isothermally and reversibly from 1L to 5L at 300 K. The change in enthalpy (in kJ) is
(R = 8.3 J K$^{-1}$ mol$^{-1}$)

For which reaction $ \Delta H \neq \Delta U $?

Consider the following reaction A(g) + 3B(g) $ \longrightarrow $ 2C(g); $ \Delta H^\ominus = -24 $ kJ. At $25 \, ^\circ\text{C}$ if $ \Delta G^\ominus $ of the reaction is -9 kJ, the standard entropy change (in JK$^{-1}$) of the same reaction at same temperature is

For a first-order reaction, the rate constant $ k $ is $ 1.386 \times 10^{-3} \, \text{s}^{-1} $. What is the half-life $ t_{1/2} $ of the reaction? (Use $ \ln 2 = 0.693 $)

The rate constant for a first-order reaction is $ 0.0693 \, \text{min}^{-1} $. What is the half-life of the reaction?

For a first-order reaction, the ratio between the time taken to complete $\frac{3}{4}$th of the reaction and time taken to complete half of the reaction is

A → P is a first order reaction. At T(K), the concentration of reactant (A) after 10 min of the reaction is $x$ mol L$^{-1}$. After 20 min, the concentration of A is $y$ mol L$^{-1}$. What is its rate constant (in min$^{-1}$)?

The following equation is obtained for a first order reaction at 300 K.
$\log_{10} \frac{k}{A} = 0.00174$ What is the activation energy (in J mol$^{-1}$) of the reaction ?
(R = 8.314 J mol$^{-1}$ K$^{-1}$)

The decomposition of AB$_3$(g) is a zero order reaction. At 300 K, the rate constant of the reaction is $2.5 \times 10^{-4}$ mol L$^{-1}$ s$^{-1}$. What is the rate of reaction (in mol L$^{-1}$ s$^{-1}$) when the concentration of AB$_3$(g) is taken as 10$^{-1}$ mol L$^{-1}$ at 300 K?

$R \to P$ is a first-order reaction. The concentration of R changed from 0.04 to 0.03 mol L$^{-1}$ in 40 minutes. What is the average velocity of the reaction in mol L$^{-1}$ s$^{-1}$?

The time required for 100% completion of a zero order reaction is
[$R$]$_0$ = Initial concentration of reactant, R

A → P is a first order reaction. The reaction was started at 10.00 AM. At 10.10 AM, the concentration of A was x mol L^-1. At 10.20 AM, the concentration of A was y mol L^-1. The half life (in min) of the reaction is equal to:

At T(K), the following equation is obtained for a first order reaction.
\[ \log \frac{k}{A} = -\frac{x}{T} \] The activation energy for this reaction is equal to (R = gas constant)

For the reaction $ \text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g) $ at 298 K, the enthalpy change $ \Delta H = -92.4 \, \text{kJ/mol} $. What happens to the equilibrium when temperature is increased?

At 700 K, the equilibrium constant $K_e$ for the reaction $ \text{N}_2(g) + 3\text{H}_2(g) \rightleftharpoons 2\text{NH}_3(g) $ is 0.2 mol L$^{-2}$. What is the value of $K$ for the reverse reaction?

At T(K), consider the following gaseous reaction, which is in equilibrium: N$_2$O$_5 \rightleftharpoons 2$NO$_2 + \frac{1}{2}$O$_2$. What is the fraction of N$_2$O$_5$ decomposed at constant volume and temperature, if the initial pressure is 300 mm Hg and pressure at equilibrium is 480 mm Hg? (Assume all gases as ideal)

At 298 K, the value of K$_p$ for N$_2$O$_4$(g) $\rightleftharpoons$ 2NO$_2$(g) is 0.113 atm. The partial pressure of N$_2$O$_4$ at equilibrium is 0.2 atm. What is the partial pressure (in atm) of NO$_2$ at equilibrium ?

At 298 K, the value of $K_c$ for the reaction A$_2$O$_4$(g) $\rightleftharpoons$ 2AO$_2$(g) is $x$ mol L$^{-1}$. What is the approximate $K_p$ value for this reaction?
Given: $R = 0.082$ L atm mol$^{-1}$ K$^{-1}$

The following equilibrium is established at STP:
\[ B_2 (g) \rightleftharpoons 2B(g) \] Atoms of B occupy 20% of total volume at STP. The total pressure of the system is 1 bar. What is its $K_p$? (STP volume = 22.7 L)

At T(K), the equilibrium constant for the reaction \[ {N}_2(g) + 3{H}_2(g) \rightleftharpoons 2{NH}_3(g) \] is $6 \times 10^{-2}$. At equilibrium, if the molar concentrations of ${H}_2$ and ${NH}_3$ are 0.25 M and 0.06 M respectively, the equilibrium concentration of dinitrogen (in mol L$^{-1}$) is:

At T(K), $ K_c $ value for the dissociation of $ \text{PCl}_5 $ is 0.04.
\[ \text{PCl}_5(g) \rightleftharpoons \text{PCl}_3(g) + \text{Cl}_2(g) \] The number of moles of $ \text{PCl}_5 $ to be added to a 3.0 L flask to get chlorine concentration of 0.15 mol L$^{-1}$ is (approximately)?

At temperature $ T(K) $, the equilibrium constant $ K_c $ for the reaction: $$ \mathrm{AO_2(g) + BO_2(g) \rightleftharpoons AO_3(g) + BO(g)} $$ is 16. In a 1 L flask, one mole each of $\mathrm{AO_2}$, $\mathrm{BO_2}$, $\mathrm{AO_3}$, and $\mathrm{BO}$ are taken and heated to $ T(K) $. Identify the correct statements:

Total number of moles at equilibrium is 4
At equilibrium, the ratio of moles of $\mathrm{AO_2}$ and $\mathrm{AO_3}$ is 1:4
Total number of moles of $\mathrm{AO_2}$ and $\mathrm{BO_2}$ at equilibrium is 0.8

At 25 $^{\circ}$C, $ K_a $ of acetic acid is $ 1.8 \times 10^{-5} $. What is the percentage of ionization of 0.02 M acetic acid at this temperature?