Number of S = O bonds in pyrosulphuric acid are

Options

A. Two
B. Four
C. Five
D. Six

Answer

To determine the number of S=O (sulfur double bond oxygen) bonds in pyrosulphuric acid (H₂S₂O₇), we can follow these steps:

### Step 1: Understand the Chemical Formula
The chemical formula for pyrosulphuric acid is H₂S₂O₇. This indicates that the compound contains two sulfur (S) atoms and seven oxygen (O) atoms.

**Hint:** Remember that the subscripts in a chemical formula indicate the number of each type of atom present in the molecule.

### Step 2: Draw the Structure of Pyrosulphuric Acid
To visualize the bonding, we need to draw the Lewis structure of H₂S₂O₇. The structure can be represented as follows:

- Start with the two sulfur atoms connected by a single bond (S-S).
- Each sulfur atom will be bonded to oxygen atoms.
- One sulfur atom will have two double bonds to oxygen (S=O) and one single bond to an OH group (O-H).
- The other sulfur atom will also have two double bonds to oxygen (S=O) and one single bond to another OH group.

The structure can be summarized as:
- S1: 2 double bonds to O and 1 single bond to OH
- S2: 2 double bonds to O and 1 single bond to OH

**Hint:** Drawing the structure helps in visualizing how the atoms are connected and how many bonds exist between them.

### Step 3: Count the S=O Bonds
Now, we can count the S=O bonds in the structure we have drawn:
- From the first sulfur atom (S1), there are 2 S=O bonds.
- From the second sulfur atom (S2), there are also 2 S=O bonds.

Adding these together gives us:
- Total S=O bonds = 2 (from S1) + 2 (from S2) = 4 S=O bonds.

**Hint:** Make sure to recount the bonds to ensure accuracy.

### Conclusion
Thus, the total number of S=O bonds in pyrosulphuric acid (H₂S₂O₇) is **4**.

**Final Answer:** There are 4 S=O bonds in pyrosulphuric acid.