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
Answer:
O.1M
Explanation:
First let's generate a balanced equation for the reaction
NaOH + HCl —>NaCl + H2O
From the equation,
The ratio of the acid to base is 1:1.
From the question, we obtained the following:
Ma = Molarity of acid = 0.12M
Va = volume of acid = 21.35cm3
Vb = volume of base = 25.55cm3
Mb = Molarity of base =?
We obtained nA(mole of acid) and nB(mole of base) to be 1
The molarity of the base can be calculated for using:
MaVa/ MbVb = nA / nB
0.12x21.35 / Mb x 25.55 = 1
Cross multiply to express in linear form
Mb x 25.55 = 0.12x21.35
Divide both side by 25.55
Mb = (0.12x21.35) / 25.55
Mb = 0.1M
The molarity of the base is 0.1M
Answer: Option (c) is the correct answer.
Explanation:
When a system is open then there will be exchange of energy between the system and surrounding.
Whereas when a system is closed then there will be no exchange of energy, that is, thermal energy will not flow into the atmosphere.
Thus, we can conclude that a sealed calorimeter is a closed system because thermal energy is not transferred to the environment.
Answer:
The different angles the moon has from sunlight to the earth
Explanation:
Answer:
A. Cell
Explanation:
Cells are basic units of structure and function in living things. This means that cells form the parts or an organism and carry out all of the an organism's processes, or functions.
