Determine the pHpH of an HFHF solution of each of the following concentrations. In which cases can you not make the simplifying assumption that xx is small? (KaKa for HFHF is 6.8×10−46.8×10−4.)

The question is incomplete, complete question is :

Determine the pH of an HF solution of each of the following concentrations. In which cases can you not make the simplifying assumption that x is small? ( for HF is .)

[HF] = 0.280 M

Express your answer to two decimal places.

The pH of an 0.280 M HF solution is 1.87.

Explanation:3

Initial concentration if HF = c = 0.280 M

Dissociation constant of the HF =

Initially

c          0            0

At equilibrium :

(c-x)      x             x

The expression of disassociation constant is given as:

Solving for x, we get:

x = 0.01346 M

So, the concentration of hydrogen ion at equilibrium is :

The pH of the solution is ;

The pH of an 0.280 M HF solution is 1.87.

with this one i know the answer in craters one reason i looked it up and i learned about it there is my evidence

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml