Which among the following are, respectively, the correct oxidation numbers of chloride ion in Cl2O7, Cl2O, ClO3- and ClO2-?
+7, +1, +5, +3
Oxygen is assigned an oxidation number of -2 in each species, and the sum of oxidation numbers must equal the overall charge (0 for a neutral molecule, -1 for a singly charged anion).
In \(Cl_2O_7\): \(2x + 7(-2) = 0 \Rightarrow 2x = 14 \Rightarrow x = +7\).
In \(Cl_2O\): \(2x + 1(-2) = 0 \Rightarrow 2x = 2 \Rightarrow x = +1\).
In \(ClO_3^-\): \(x + 3(-2) = -1 \Rightarrow x = -1 + 6 = +5\).
In \(ClO_2^-\): \(x + 2(-2) = -1 \Rightarrow x = -1 + 4 = +3\).
Hence, the respective oxidation numbers of chlorine are +7, +1, +5, +3.
Match List-I with List-II and select the correct answer using the code given below the Lists :
| List-I (Constituent of Paint) | List-II (Example) | ||
|---|---|---|---|
| A. | Pigment | 1. | Zinc oxide |
| B. | Extender | 2. | China clay |
| C. | Thinner | 3. | Naphthenate |
| D. | Drier | 4. | Turpentine |
With reference to fossil fuels, consider the following statements :
1. Coal is the most abundant fossil fuel and has high specific energy and energy density.
2. The action of heat and pressure changes plant matter in stages from anthracite to bituminous to lignite coal.
Which of the statements given above is/are correct?
Which one of the following statements is correct?
Which of the following pair is correct?
I. Isotopes – different mass numbers
II. Isobars – different atomic numbers
Which of the following is a zone of a flame?
I. Dark
II. Luminous
III. Non-Luminous
The volume of CO 2liberated at STP when 10 gm of 90% pure limestone strongly heated is
Water can dissolve more substances than any other liquid because
An alloy is: