Question

What is the arrow pointing to?

The figure shows a solution of different molecules. Most of these molecules consist of two small atoms attached to a bigger one. Some of the molecules are negatively charged, and consist of one big atom connected to the small one. These molecules are pointed by an arrow. There are also small positively charged atoms.
A. hydronium ion
B. hydroxide ion
C. water
D. proton
E. hydrogen ion

Answer 1

The arrow is pointing to negatively charged molecules in the solution that are likely hydroxide ions (OH-), as they fit the description of a molecule consisting of a big atom connected to a small one and being pointed at by an arrow in the context of proton movement from a hydronium ion.

Step-by-step explanation:

The arrow in the figure is pointing to molecules that are negatively charged, consisting of one big atom connected to a small one. Based on the information provided, these negatively charged molecules are likely hydroxide ions (OH-). The description suggests that the arrow shows the movement of a proton from the hydronium ion to the hydroxide ion, meaning that H3O+ is donating a proton to OH-, which does not align with the characteristics of a hydronium ion as it does not itself accept an electron pair. Instead, it acts as a proton source coordinating with a Lewis base. Therefore, the correct answer is B. hydroxide ion.

Answer 2

b. Hydroxide ion

Step-by-step explanation:

The most abundant molecules, consisting in two small atoms attached to a bigger one, are water molecules. Water molecules have two hydrogen atoms, which are the small atoms, and one oxygen atom, which is the bigger one. Water can dissociate, forming hydroxide (
`OH^(-)`) and hydronium (
`H^(+)`). If the arrow is pointing at a negatively charged molecule, that consists of one big atom attached to a smaller one, what this arrow is pointing to is an oxygen atom attached to an hydrogen atom, with a negative charge that was "stolen" from the hydrogen that was separated from the water molecule. So, the arrow is pointing to the hydroxide ion.