Question

properties of water and ph 1. write the chemical equation for water, and draw a stick model of a water molecule. show polarity by label positive and negatively charged regions of the molecule.

Explanation:

Step1: Chemical Equation for Water Formation

Water is formed from hydrogen and oxygen. The chemical reaction is the combination of hydrogen gas ($H_2$) and oxygen gas ($O_2$) to form water ($H_2O$). The balanced chemical equation is $2H_2 + O_2
ightarrow 2H_2O$. Also, the self - ionization of water is $H_2O
ightleftharpoons H^ + + OH^ -$. But for the formation of water, the combination reaction is more relevant here.

Step2: Stick Model of Water Molecule

A water molecule ($H_2O$) has a bent (angular) shape with an $H - O - H$ bond angle of approximately $104.5^{\circ}$. In the stick model, we represent the oxygen atom in the center, bonded to two hydrogen atoms.

• Polarity Labeling: The oxygen atom is more electronegative than hydrogen. So, the oxygen atom has a partial negative charge ($\delta^-$), and each hydrogen atom has a partial positive charge ($\delta^+$). The oxygen atom is bonded to two hydrogen atoms, and the lone pairs of electrons on the oxygen (not shown in a simple stick model but relevant for polarity) also contribute to the molecular polarity. The stick model can be drawn as two lines (representing the $O - H$ bonds) coming out of the oxygen atom at an angle of about $104.5^{\circ}$, with the oxygen labeled $\delta^-$ and each hydrogen labeled $\delta^+$.

Answer:

• Chemical Equation for water formation: $2H_2(g)+O_2(g)

ightarrow 2H_2O(l)$ (or self - ionization: $H_2O(l)
ightleftharpoons H^+(aq)+OH^-(aq)$)

• Stick Model: A central $O$ atom with two $H$ atoms bonded to it at an angle of ~$104.5^{\circ}$. $O$ is labeled $\delta^-$, each $H$ is labeled $\delta^+$.