List of top Chemistry Questions

Which of the following elements is the most chemically similar to Na?
A student wished to produce only carbon from the dioxide and water vapour combustion of methane, CH\(_4\). To accomplish this the student should
Argon crystallises in fcc arrangement and the density of solid and liquid Ar is 1.59 g/cm\(^3\) and 1.42 g/cm\(^3\), respectively. The percentage of empty space in liquid Ar is
When the solids Ba(OH)2 and NH4SCN are mixed, a solution is produced and the temperature drops. \[ {Ba(OH)}_2(s) + 2{NH}_4{SCN}(s) \rightarrow {Ba(SCN)}_2(aq) + 2{NH}_3(g) + 2{H}_2{O}(l) \] Which statement about the energetics of this reaction is correct?
When the following 1.0 mol dm\(^{-3}\) aqueous solutions are arranged in order of increasing pH, which is the correct order?

I. Ammonium chloride
II. Ammonium ethanoate
III. Sodium ethanoate
Choose the one false statement.
The vapour pressure of pure water is 23.5 mm Hg. Then, the vapour pressure of an aqueous solution which contains 5 mass percent of urea is (Molar mass of urea is 60).
Ammonia reacts with water to form the ammonium ion and hydroxide ion. \[ {NH}_3 + {H}_2{O} \longrightarrow {NH}_4^+ + {OH}^- \] According to the Bronsted-Lowry definition of acids and bases, what is the conjugate acid of ammonia?
A balloon contains 2.0 g of hydrogen gas. A second balloon contains 4.0 g of helium gas. Both balloons are at the same temperature and pressure. Pick the false statement from the following list.
On combustion of x-g of ethanol in a bomb calorimeter, y-joules of heat energy is produced. The heat of combustion of ethanol (\(\Delta H_{{comb}}\)) is
The reaction below represents the Haber process for the industrial production of ammonia, \[ N_2(g) + 3H_2(g) \rightleftharpoons 2NH_3(g); \Delta H^\circ = -92 \, {kJ} \] The optimum conditions of temperature and pressure are chosen as a compromise between those that favour a high yield of ammonia and those that favour a fast rate of production. Economic considerations are also important. Which statement is correct?
An object experiences a greater buoyant force in seawater than in fresh water. The most likely reason for this is
Beryllium gives a compound X with the following percentage composition: Be = 6.1%, N = 37.8%, Cl = 48%, H = 8.1%. The molecular weight of X is 148 g/mol and that of Be is 9 g/mol. The molecular formula of the compound is:
Which of the following represents an ester?
Which of the following expressions represents the solubility product for Cu(OH)$_2$?
Given a molecule with the general formula AB, which one of the following would be the most useful in determining whether the molecule was bent or linear?
Among \( [\text{Ni(CN)}_4]^{2-} \), \( [\text{NiCl}_4]^{2-} \), and \( [\text{Ni(CO)}_4] \), which one has the following:
When 2.00 g of a certain volatile liquid is heated, the volume of the resulting vapour is 821 mL at a temperature of 127°C at standard pressure. The molecular mass of this substance is:
\(\text{NH}_3\) has a \( K_b \) of \( 1.8 \times 10^{-3} \). Which of the following has a \( 5.6 \times 10^{-10} \)?
All of the following may be true concerning catalysts and the reaction which catalyse except,
Among all the given compounds, which will have D-configuration?
Which of the following stereoisomers is a major image of itself?
Calculate the mass percent of 60 g H2SO4 dissolved in the solution of 180 mL of water.
What is the minimum power required for heat engine to lift a 80 kg mass 5 m in 20 s if it releases 1000 J of heat energy from its exhaust each second?
What happens when the temperature of a reaction increases?