Since it is an ionic compound. it would be a good electrical conductor
I’d say for the answer 13.13 mmHg?
I think the mass the mass was less than the original because a gas was released into the atmosphere. The mass in a chemical reaction is constant in a closed system according to conservation of mass law. However, if a chemical reaction is completed in an open system, mas changes may occur. In our case i think the change in mass was due to the release of hydrogen gas from the reaction to the atmosphere.
The type of bonding present in water (H2O) is hydrogen bonding.