<span>The correct answer should be two oxygen atoms. That's because it's properties are similar to carbon insofar that it can form four bonds, so if it forms bonds with 2 oxygen atoms then it will have all four bonds created since Oxygen forms double bonds. This would make SiO2 which is also known worldwide as silica.</span>
When we can get Pka for K2HPO4 =6.86 so we can determine the Ka :
when Pka = - ㏒ Ka
6.86 = -㏒ Ka
∴Ka = 1.38 x 10^-7
by using ICE table:
H2PO4- → H+ + HPO4
initial 0.4 m 0 0
change -X +X +X
Equ (0.4-X) X X
when Ka = [H+][HPO4] / [H2PO4-]
by substitution:
1.38 X 10^-7 = X^2 / (0.4-X) by solving for X
∴X = 2.3x 10^-4
∴[H+] = X = 2.3 x 10^-4
∴PH = -㏒[H+]
= -㏒ (2.3 x 10^-4)
∴PH = 3.6
Answer:
Hydrogen peroxide should be stored in
1) a cool environment
2) with amber bottles away from sunlight
3) with little drops of sodium phosphate
Explanation:
It has been confirmed that heat and light aids in the decomposition of hydrogen peroxide according to the equation; 2H2O2→2 H2O + O2.
This means that hydrogen peroxide must be stored in a cool place. This will reduce its rate of decomposition. Secondly, it should be stored in amber bottles away from light since light also aids in its decomposition.
Thirdly, drops of sodium phosphate may be added to prevent its catalytic decomposition during storage.
In this question, you are given the NaOH volume but asked for concentration.
Don't forget that for every 1 mol of NaOH there will be 1 mol OH- ion, but for every 1 mol of H2SO4 there will be 2 mol of H- ion.
To neutralize you need the same amount of OH- and H+, so the equation should be:
OH-= H+
<span>35.50cm3 * x*1= 25cm3* 0.2mol/dm3 *2
</span>x= 10/35.5 mol/dm3= 0.2816/dm3
