Which would be an example of a compound?<br> oxygen<br> carbon dioxide<br> sand<br> carbon

What is the pH of 0.26 M ammonium ion? NH4+(aq) + H2O(1) NH3(aq) + H30* (aq) a. 4.33 b.9.25 c. 3.87 d. 4.92 e. 4.75

choli [55]

Answer:

b) pH = 9.25

Explanation:

NH4+(aq) + H2O(l) ↔ NH3(aq) + H3O+(aq)
NH3 + H2O ↔ NH4+ + OH-
2 H2O ↔ H3O+ + OH-

⇒ Kb = [ NH4+ ] * [ OH- ] / [ NH3 ] = 1.86 E-5......from literature

mass balance NH4+:

⇒ M NH4+ = [ NH4+ ] - [ OH- ]

∴ [ NH3 ] ≅ M NH4+ = 0.26 M

⇒ Kb = (( 0.26 + [ OH- ] )) * [ OH- ] / 0.26 = 1.86 E-5

⇒ 0.26 [ OH-] + [ OH- ]² = 4.836 E-6

⇒ [ OH- ]² + 0.26 [ OH- ] - 4.836 E-6 = 0

⇒ [ OH- ] = 1.859 E-5 M

⇒ pOH = - Log ( 1.859 E-5 )

⇒ pOH = 4.7305

⇒ pH = 14 - pOH = 9.269

6 0

3 years ago

(vii). Give two uses of chlorine gas.

Strike441 [17]

Answer: A yellowy-green dense gas with a choking smell. Chlorine kills bacteria – it is a disinfectant. It is used to treat drinking water and swimming pool water. It is also used to make hundreds of consumer products from paper to paints, and from textiles to insecticides.

Explanation: hope this helps u! HAppy Holidays!

7 0

3 years ago

Is there a way to dissolve more sugar into a solution that it should hold at that temperature? Explain how this is done and what

Darya [45]

The answer is: supersaturated solution.

A supersaturated solution contains more of the dissolved substance than could be dissolved by the solvent under normal circumstances.

A way to dissolve more sugar into a solution is heating a solution.

The more heat is added to a system, the more soluble a substance (in this example sugar) becomes.

The solution will become supersaturated if this solution is suddenly cooled at a rate faster than the rate of precipitation.

6 0

3 years ago

If 15.0 mL of phosphoric acid completely neutralizes 38.5 mL of 0.150 mol/L calcium hydroxide, what is the concentration of the

Sedbober [7]

Answer:

Let me give it a try.

H3PO4 + Ca(OH)2 = Ca3(PO4)2 + H2O

Balancing this reaction

2H3PO4 + 3Ca(OH)2 == Ca3(PO4)2 + 6H2O.

Moles= Molarity x Volume

Volume = 38.5ml = 0.0385L

Moles of Ca hydroxide = 0.150m/L x 0.0385L

(Notice the units canceling out...leaving moles).

=0.005775moles of Ca(OH)2.

From balanced reaction...

3moles of Ca(OH)2 completely reacts with 2moles of H3PO4

0.005775moles of Ca(OH)2 would completely react with....

= 0.005775 x 2/(3)

=0.00385moles of H3PO4.

Now we're looking for its Concentration in Mol/L

Molarity=Moles of solute/Volume of solution(in L)

Volume of solution assuming no other additions to the reaction = 15ml + 38.5ml =53.5ml =0.0535L

Molarity = 0.00385/0.0535

=0.072Mol/L.

If this is wrong

then Simply Try The formula for Mixing of solutions

C1V1 = C2V2

0.15 x 38.5 = C2 x (15+38.5)

C2 = 0.11M/L.

7 0

3 years ago

Equation for hydrogen

Sergio [31]

The chemical equation for Hydrogen is just H

5 0

3 years ago

Which would be an example of a compound? oxygen carbon dioxide sand carbon