This question refers to significant figures. The reason we follow significant figure rules when performing calculations in science is that a calculated answer (which is an extrapolation of a manipulation of measurements) can only be as precise as the least precise measurement recorded. This means if you record measurements to a certain precision, the calculated answer at the most can only match the recorded level of precision as to balance the level of confidence in accuracy before and after calculations.
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
<span>The answer is Mandy’s solution is a
Base/Alkaline solution. Alkaline solution turns
red litmus blue while acidic solution turns
blue litmus red. In acidic solution, the red litmus remains red while in
alkaline solution, the blue litmus remains blue. However, litmus paper can never tell you the exact pH
number of a solution</span>
Answer:
Gas is for example oxygen or the air we breath and liquid is water.
Explanation:
