Clarify the cause of selecting dil. HCl instead of dil. H$_2$SO$_4$ during laboratory preparation of

In the lab preparation of carbon dioxide ($\rm CO_{2}$), dilute hydrochloric acid ($\rm HCl $) is chosen over dilute sulphuric acid ($\rm H_{2}SO_{4} $) because $\rm H_{2}SO_{4} $ can form an insoluble layer of calcium sulphate ($\rm CaSO_{4} $) when it reacts with calcium carbonate ($\rm CaCO_{3} $). This layer stops the reaction, limiting $\rm CO_{2}$ production. Dilute $\rm HCl $ , however, reacts smoothly with $\rm CaCO_{3} $ to produce a steady release of $\rm CO_{2}$ gas without forming any obstructive by-products.

The tests needed to be performed before entering into well to prevent from the suffocation are:

Oxygen Test: Lower a burning candle or flame into the well to check for oxygen. If the flame extinguishes quickly, it indicates a lack of oxygen, which could lead to suffocation.
$\rm CO_{2}$ Test: Lower a container with limewater into the well. If the limewater turns milky, it shows high $\rm CO_{2}$ levels, which could be dangerous for breathing.

These tests are essential for safety to avoid suffocation risks due to low oxygen or high $\rm CO_{2}$ levels in confined spaces like wells.

Clarify the cause of selecting dil. HCl instead of dil. H$_2$SO$_4$ during laboratory preparation of carbon dioxide. What tests do you need to perform before entering into well to prevent from the suffocation?