Answer:
A device that does work with only one movement and changes the size or direction of a force is a simple machine.
Explanation:
- For applying force, any used basic mechanical devices are simple machines.
- Simple machine changes the direction as well as the amplitude of the applied force i.e. we can increase or decrease the magnitude of the force.
- A simple machine is the most basic mechanism to use the force as we need in big mechanical machines.
- Some of the examples of simple machines are inclined plane, lever, wedge, wheel and axle, pulley, and screw.
Complete Question
You determine that it takes 26.0 mL of base to neutralize a sample of your unknown acid solution. The pH of the solution was 7.82 when exactly 13 mL of base had been added, you notice that the concentration of the unknown acid was 0.1 M. What is the pKa of your unknown acid?
Answer:
The pK_a value is
Explanation:
From the question we are told
The volume of base is 
The pH of solution is 
The concentration of the acid is 
From the pH we can see that the titration is between a strong base and a weak acid
Let assume that the the volume of acid is 
Generally the concentration of base

Substituting value


When 13mL of the base is added a buffer is formed
The chemical equation of the reaction is

Now before the reaction the number of mole of base is
![No \ of \ moles[N_B] = C_B * V_B](https://tex.z-dn.net/?f=No%20%5C%20of%20%5C%20moles%5BN_B%5D%20%20%3D%20%20C_B%20%2A%20V_B)
Substituting value

Now before the reaction the number of mole of acid is

Substituting value


Now after the reaction the number of moles of base is zero i.e has been used up
this mathematically represented as

The number of moles of acid is


The pH of this reaction can be mathematically represented as
![pH = pK_a + log \frac{[base]}{[acid]}](https://tex.z-dn.net/?f=pH%20%20%3D%20pK_a%20%2B%20log%20%5Cfrac%7B%5Bbase%5D%7D%7B%5Bacid%5D%7D)
Substituting values

Answer:The molar mass is the mass of a given chemical element or chemical compound (g) divided by the amount of substance (mol).
The molar mass of a compound can be calculated by adding the standard atomic masses (in g/mol) of the constituent atoms.
Explanation:
Answer:
the answer is A
I made a chart for AP chem if you want to refer to it.