This is a bit of a tricky question, as it depends on what you mean by "soft rock" and "boiling point".

Here's a breakdown:

* "Soft rock" is a subjective term. It could refer to rocks that are easily broken, like sedimentary rocks like limestone or sandstone. It could also refer to rocks that are relatively low in density, like pumice.

* Rocks don't have a single "boiling point". They are made of different minerals, each with its own melting point. When a rock is heated, different minerals will melt at different temperatures, eventually forming a liquid called magma.

So, what happens to a soft rock heated almost to its boiling point?

* It will likely melt and deform. Different minerals will start to melt at different temperatures, causing the rock to weaken and change shape.

* The exact change depends on the rock's composition. A rock with a lot of quartz will be harder to melt than a rock with a lot of feldspar.

* It won't necessarily "boil" like water. There isn't a single boiling point for rocks, and they don't turn into a gas like water does.

In summary, a "soft rock" heated almost to its boiling point will likely melt and deform, but the specific changes will depend on the rock's composition.