What is the ratio of acetate ion to acetic acid (Ka = 1.76×10–5) in a solution containing these compounds at pH 4.38 ? Write your answer as a decimal and not as a fraction.

0.43.

Explanation:

In order to solve this question we will need the an equation called Henderson-Hasselbalch Equation. The Henderson-Hasselbalch Equation can be represented by the reaction below;

pH= pKa + log ( [ A^- ] / [ HA] ).

Where HA is the acetic acid and A^- is the Acetate ion

We are given the pH value to be = 4.38 and the ka to be = 1.76×10^–5. So, we will use the value for the ka to find the pKa through the formula below.

pKa = - log ka.

Therefore, pKa = - log( 1.76×10^–5).

pKa= 4.75 + log

So,

4.38 = 4.75 + log ([ A^-] / [HA]).

4.38 - 4.75 = log ( [ A^- ] / [ HA] ).

( [ A^- ] / [ HA] ) = 10^- 0.37.

( [ A^- ] / [ HA] ) = 0.42657951880159265.

( [ A^- ] / [ HA] )= 0.43.

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.