You know that an unlabeled water bottle contains at least some water. you measure the freezing point of the unknown substance and find that it freezes at a temperature lower than 0 degrees celsius at 1 atmosphere pressure. which of the following can you conclude?

the substance is pure water.

the substance will have a boiling point that is less than 100 degrees celsius.

the substance will have a vapor pressure that is greater than that of pure water.

the substance is an aqueous solution.

The substance is an aqueous solution

An aqueous solution that contains non-volatile solute will have a lower freezing point, higher boiling point, and lower vapor pressure compared to pure water

- lead + phosphoric acid = hydrogen + lead(ii) phosphate

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."