When a gas bubbles through water, small droplets of water are usually picked up along for the ride and are mixed in with the gas above the water inside the eudiometer tube. The water vapor takes up room, but isn't the important gas that you need to measure. The table of water vapor is needed to subtract the unwanted water vapor from the collection of gases.
Answer:
SeCl₆ < SeF₂ < SeO₂
Explanation:
(A) SeO₂
The central atom has 2 bond pairs and 1 lone pair. The molecule is bent shaped which has an angle of 120°.
(B) SeCl₆
The central atom has 6 bond pairs and 0 lone pair. The geometry is octahedral in which the equatorial bonds has an angle of 90° and axial bond has an angle of 90°.
(C) SeF₂
The central atom has 2 bond pairs and 2 lone pairs. The geometry is bent shape which has an angle of approximately 105.5°.
The order is:
<u>SeCl₆ < SeF₂ < SeO₂</u>
Because the valence shell of gases wants to become full
Carbon dioxide and water pretty sure