10% solution means=
= 
= 100 mg/mL
If the dentist inject 0.3 mL, that is equal to 0.3× 100 mg.
If the dentist inject 0.3 mL, that is equal to 30 mg.
So, as anesthetic procaine hydrochloride is often used to deaden pain during dental surgery. the compound is packaged as a 10.% solution (by mass; d = 1.0 g/ml) in water. When our dentist
injects 0.30 ml of the solution, 30 mg of procaine hydrochloride (in milligrams) is injected.
<span>Pentanol contains five carbons and has a hydroxyl group on the second carbon.
(C5H11OH)</span>
Answer:
The correct answer is 574.59 grams.
Explanation:
Based on the given information, the number of moles of NH₃ will be,
= 2.50 L × 0.800 mol/L
= 2 mol
The given pH of a buffer is 8.53
pH + pOH = 14.00
pOH = 14.00 - pH
pOH = 14.00 - 8.53
pOH = 5.47
The Kb of ammonia given is 1.8 * 10^-5. Now pKb = -logKb,
= -log (1.8 ×10⁻⁵)
= 5.00 - log 1.8
= 5.00 - 0.26
= 4.74
Based on Henderson equation:
pOH = pKb + log ([salt]/[base])
pOH = pKb + [NH₄⁺]/[NH₃]
5.47 = 4.74 + log ([NH₄⁺]/[NH₃])
log([NH₄⁺]/[NH₃]) = 5.47-4.74 = 0.73
[NH₄⁺]/[NH₃] = 10^0.73= 5.37
[NH₄⁺ = 5.37 × 2 mol = 10.74 mol
Now the mass of dry ammonium chloride required is,
mass of NH₄Cl = 10.74 mol × 53.5 g/mol
= 574.59 grams.
Answer:
5) donating H to a solution when they have been depleted and accepting H when they are in excess.
Explanation:
A buffer solution is a solution that undergoes a negligible change in pH in addition of moderate quantities of acid or alkali. In other words, a buffer solution is one that resists a change in pH on addition or dilution of small amounts of acids or alkalis.
So, from the given question:
Buffers are substances that help resist shifts in pH by donating H to a solution when they have been depleted and accepting H when they are in excess.
