Import Question JSON

Current Question (ID: 9114)

Question:

$\text{The incorrect statement about alkali metals is -}$

Options:

1. $\text{They have low density.}$
2. $\text{They have high ionization enthalpy.}$
3. $\text{They are highly reactive.}$
4. $\text{They show photoelectric effect.}$

Solution:

$\text{Hint: Alkali metals are most electropositive in nature.}$ $\text{EXPLANATION-}$ $\text{(1) They are quite soft and can be cut easily. Sodium metal can be easily cut using a knife.}$ $\text{(2) They are light coloured and are mostly silvery-white in appearance.}$ $\text{(3) They have low density because of the large atomic sizes. The density increases down the group from Li to Cs. The only exception to this is K, which has a lower density than Na.}$ $\text{(4) The metallic bonding present in alkali metals is quite weak. Therefore, they have low melting and boiling points.}$ $\text{(5) Alkali metals and their salts impart a characteristic color to flames. This is because the heat from the flame excites the electron present in the outermost orbital to a high energy level. When this excited electron reverts back to the ground state, it emits excess energy as radiation that falls in the visible region.}$ $\text{(6) They also display a photoelectric effect. When metals such as Cs and K are irradiated with light, they lose electrons.}$

Import JSON File

Upload a JSON file containing LaTeX/MathJax formatted question, options, and solution.

Expected JSON Format:

{
  "question": "The mass of carbon present in 0.5 mole of $\\mathrm{K}_4[\\mathrm{Fe(CN)}_6]$ is:",
  "options": [
    {
      "id": 1,
      "text": "1.8 g"
    },
    {
      "id": 2,
      "text": "18 g"
    },
    {
      "id": 3,
      "text": "3.6 g"
    },
    {
      "id": 4,
      "text": "36 g"
    }
  ],
  "solution": "\\begin{align}\n&\\text{Hint: Mole concept}\\\\\n&1 \\text{ mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6] = 6 \\text{ moles of carbon atom}\\\\\n&0.5 \\text{ mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6] = 6 \\times 0.5 \\text{ mol} = 3 \\text{ mol}\\\\\n&1 \\text{ mol of carbon} = 12 \\text{ g}\\\\\n&3 \\text{ mol carbon} = 12 \\times 3 = 36 \\text{ g}\\\\\n&\\text{Hence, 36 g mass of carbon present in 0.5 mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6].\n\\end{align}",
  "correct_answer": 4
}