Tag: chemistry

Quizzes (490) Questions (9892)

Questions Related to chemistry

Multiple choice chemistry combustion and flame structure of flame flame combustion

Substance which vaporize during burning gives ____________.

  1. sound

  2. flame

  3. combustion

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Substances which vaporize during burning gives flame. For example, combustion of kerosene oil produces a flame. On the other hand, certain substances like coal do not vaporize and hence does not produce a flame.

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

The stability of an ionic compound is mostly due to:

  1. ionization energy

  2. electron affinity

  3. lattice energy

  4. electronegativity
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lattice energy is a measure of energy released in ionic crystals when the ions are brought together from infinity. It measures the attraction between ions so that they are held in a position. Ionic compound stability is mostly due to lattice energy.

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

Decreasing order of lattice energy of $FeO, Fe _2O _3, NaCl$ is:

  1. $NaCl>FeO>Fe _2O _3$
  2. $Fe _2O _3>FeO>NaCl$
  3. $NaCl>FeO=Fe _2O _3$
  4. $Fe _2O _3>NaCl>FeO$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Lattice energy is directly proportional to the product of ionic charges and inversely proportional to the inter-ionic distance. Fe2O3 has the highest charge (+3, -2), followed by FeO (+2, -2), and NaCl has the lowest charge (+1, -1).

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

The magnitude of the lattice energy of a soild increases if:

  1. the ions are large

  2. the ions are small

  3. the ions are of equal size

  4. charges on the ions are small
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Lattice energy is directly proportional to the charge on the ions and inversely proportional to the size of the ions.  Smaller the size, greater is the lattice energy.

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

Maximum lattice enthalpy is present in

  1. $K _{2}O$
  2. $CaO$
  3. $Al _{2}O _{3}$
  4. $KCl$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Lattice enthalpy increases with higher ionic charges and smaller ionic radii according to Born-Landener type relationships. Al2O3 contains highly charged Al3+ and O2- ions compared to singly or doubly charged ions in the other choices, resulting in a much higher lattice enthalpy.

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

The melting point of a material with low binding energy is:

  1. high

  2. low

  3. infinity

  4. negative
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The melting point of a material with low binding energy is low. When, the binding energy is low, the attraction between the valence electron and the nucleus is low. This also means that the intermolecular attraction is low. Hence, the melting point is low.

Multiple choice chemistry lattice energy defining lattice energy ionic or electrovalent bond energy cycles

Which pair is not correct order of lattice energy?

  1. $KCI > MgO$
  2. $AlN > MgO$
  3. $BeCO _3 > MgCO _3$
  4. $KCI < MgO$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Lattice Energy is directly proportional to the charge on the ions and inversely proportional the size of the ions. As size decreases, lattice energy increases. So $MgO$ have higher lattice energy than $KCl$.