List of top Chemistry Questions

Which of the following is the \(K_b\) for the conjugate base of carbonic acid?
A man straightens up his room. His action does not violate the second law of thermodynamics because
Which of the following groups contains only atoms that are paramagnetic in their ground state?
Aldehydes are readily oxidised to yield carboxylic acids but ketones are inert to oxidation. Which is the most likely explanation regarding this difference in reactivity?
Which of the following does not show hydrogen bonding?
H$_2$ can be added to ethylene in the presence of a heterogeneous catalyst such as solid. What might account for the initial attraction between the hydrogen molecules and the solid platinum?
Gas A decomposed according to the following reaction:
A(g) $\rightarrow$ B(g) + C(g)
A student conducted an experiment and determined that the equilibrium pressure of gas A was 0.20 P, where P was the total pressure of the system. What is the equilibrium constant $K_p$ for this reaction?
Which of the following changes to a reaction will always increase the rate constant for that reaction?
Which of the following is true for an acid-base concentration cell such as the one used by the pH meter?
Using the above information, determine the standard reduction potential for the following reaction,
\[ 2M(s) + 3Zn^{2+}(aq) \rightarrow 2M^{3+}(aq) + 3Zn(s); \quad E^\circ = 0.90V \] \[ Zn^{2+}(aq) + 2e^- \rightarrow Zn(s); \quad E^\circ = -0.76V \]
Which statement about the bonding between carbon atoms is correct?
What is the molality of a 10% (by weight) C$_6$H$_{12}$O solution (molecular weight = 90)?
Which of the following compound in its anionic form is aromatic.
A buffer is formed by adding 500 ml of 0.20 M correct to 500 mL of 0.10 M NaC H$_2$O$_2$. What would be the maximum amount of HCl that could be added to this solution without exceeding the capacity of the buffer?
Which of the following compounds will give racemic mixture on nucleophilic substitution by OH$^{-}$ ions?
The acid dissociation constant for \( HC_6H_7O_6 \) is \( 8.0 \times 10^{-5} \). If a solution contains equal concentrations of \( HC_6H_7O_6 \) and \( C_6H_7O_6^- \), what will be the pH of the solution?
Equal molar quantities of oxygen and hydrogen gas were placed in container A under high pressure. A small portion of the mixture was allowed to effuse for a very short time into the vacuum in container B. Which of the following is true concerning partial pressures of the gases at the end of the experiment?
The shortest bond would be present in which of the following substances?
Which molecular formula is also an empirical formula?
2CrO$_4^{2-}$ + 3SnO$_2^{2-}$ + H$_2$O → 2CrO$_2^{-}$ + 3SnO$_3^{2-}$ + 2OH$^{-}$
How many moles of OH$^{-}$ form when 50.0 mL of 0.100 M CrO$_4^{2-}$ is added to a flask containing 50.0 mL of 0.100 M SnO$_2^{2-}$?
An imaginary metal crystallises in a cubic lattice. The unit cell edge length is 100 pm, (1 pm = $10^{-12}$ m). The density of this metal is 200 g/cm\(^3\). The atomic mass of the metal is 60.2 g/mol. How many of these metal atoms are there within a unit cell?
NaCl dissolves spontaneously in water. Based upon the following reaction, NaCl(s) $\rightarrow$ Na$^{+}$(g) + Cl$^{-}$(g)
The values of all of the following are reversed when a reaction is reversed except
20 g of NaCl is poured into a coffee cup calorimeter containing 250 mL of water. If the temperature inside the calorimeter drops 1°C by the time, the NaCl is totally dissolved, what is the heat of solution for NaCl and water? (specific heat of water is 4.18 J/g°C)
What is the oxidation state of sulfur in HSO$_4^{-}$?