Place the elements below in order of decreasing ionization energy. Aluminum(Al) Chlorine(Cl) Magnesium (Mg) Sulfur(S)

For Na2HPO4:(( (Note that for H3PO4, ka1= 6.9x10-3, ka2 = 6.4x10-8, ka3 = 4.8x10-13 ) a) The active anion is H2PO4- b) The activ

Komok [63]

Answer:

Check the explanation

Explanation:

Answer – Given, $H_3PO_4$ acid and there are three Ka values

$K_{a1}=6.9x10^8, K_{a2} = 6.2X10^8, and K_{a3}=4.8X10^{13}$

The transformation of $H_2PO_4- (aq) to HPO_4^2-(aq)$ is the second dissociation, so we need to use the Ka2 = 6.2x10-8 in the Henderson-Hasselbalch equation.

Mass of KH2PO4 = 22.0 g , mass of Na2HPO4 = 32.0 g , volume = 1.00 L

First we need to calculate moles of each

Moles of KH2PO4 = 22.0 g / 136.08 g.mol-1

= 0.162 moles

Moles of Na2HPO4 = 32.0 g /141.96 g.mol-1

= 0.225 moles

[H2PO4-] = 0.162 moles / 1.00 L = 0.162 M

[HPO42-] = 0.225 moles / 1.00 L = 0.225 M

Now we need to calculate the pKa2

pKa2 = -log Ka

= -log 6.2x10-8

= 7.21

We know Henderson-Hasselbalch equation

pH = pKa + log [conjugate base] / [acid]

pH = 7.21 + log 0.225 / 0.162

= 7.35

The pH of a buffer solution obtained by dissolving 22.0 g of KH2PO4 and 32.0 g of Na2HPO4 in water and then diluting to 1.00 L is 7.35

6 0

3 years ago

Which formula is an empirical formula? (1) CH4 (2) C2 H6 (3) C3 H6 (4) C4 H10

rosijanka [135]

CH4 is an emprirical formula as it shows the simplest ratio of the numbers of different atoms present in the molecule. The empirical formula for CH4 is also the same as the molecular formula.
The other compunds can be simplified so they are not the empirical formula of compounds.
Hope this helps :).

3 0

3 years ago

Why are you so much older on Mercury?

Alinara [238K]

Answer:As you can see from the very different numbers in the boxes above, your age changes (sometimes quite a lot) ... Mercury is the closest planet to the Sun and so has a smaller orbit path – it takes just 88 Earth days

Explanation:

4 0

3 years ago

Read 2 more answers

PLEASE HELP I WILL GIVE YOU BRAINLIEST Provide the chemical formula for the following

a_sh-v [17]

1. CaCr2O7
2. Sodium sulfite
3. (NH4)2SO3
4. Copper (II) nitrite

8 0

3 years ago

In many of the steps in the lab, a mixture was centrifuged and then decanted. In general terms, what is accomplished by these st

nirvana33 [79]

Answer:

to separate the compounds by gravity

Explanation:

Centrifuging is the process of separating compound in a liquid mixture by means of gravity and settling. This makes use of the density principle. In the process, the sample is added to the centrifuge. This is then rotated at a certain speed, say 50 rpm. The circular motion creates a force of gravity that pulls the compounds downwards. This then separate the compounds. The heaviest and most dense go down first, then the lighter particles on the top.

3 0

3 years ago