## Tutoring Chemistry, pH Ka, Acids & Bases

You can find the pH by taking the negative log of the concentration of H+ or H3O+ and the pOH by taking the negative log of the OH-

There are various ways to do calculations with Ka and the pH.

We checked out Bronsted-Lowery acids and bases and the theory with proton donors/acceptors.

Also, with chemistry, you want to be very careful with the names since changing them slightly can mean a different substance.

And rounding early is not a good plan since it can introduce inaccuracy.

## “How do you calculate the volume of a liquid? What’s the unit of measurement?”

Volume is basically the three dimensional space that something fills. So you can place the liquid in a container with standardized markings.

Volume can change based on temperature and pressure though.

The SI unit of volume is the cubic meter. Other units used can be cubic centimeters, liters, etc. Often we choose the units based on the situation. To use units in an equation though, it’s often better to start with SI units.

You can convert between units of volume using ratios. Another simple way to convert units is just to use Google,

You can input something like this:

“Two liters is how many gallons”

Example:

You can also calculate the volume if you know the density and mass. (Again, temperature and pressure are also factors).

Density = mass/volume

Volume = mass/density

## Tutoring Chemistry, Combustion reaction

We started by looking at a problem finding the heat of combustion for acetylene in oxygen. The approach was to draw the bond structure determine the number of each type. There were coefficients in front of some terms in the reaction as well. The heat of combustion for the exothermic reaction was negative.

Looked at a few problems that were closely linked to physics including the photo electric effect and talked about the relationship of wavelength, frequency, and the speed of light. Understanding physics will make parts of chemistry make more sense.

Looked at hybridization and resonance and did a problem with the electron configuration of Chromium.

A number of things in chemistry need to be committed to memory.