Additional Practice Questions 5. If you had a pH of 4.30 in a 5.00 L sample, how many
moles of hydronium do you have?

Moles of hydronium (H₃O⁺) : 2.5 x 10⁻⁴

Given

pH = 4.3

V sample = 5 L

Required

moles of H₃O⁺(hydronium)

Solution

pH = - log [H₃O⁺]

4.3 = - log [H₃O⁺]

Moles of hydronium for 5 L sample :

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

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year