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:
The new volume if the balloon is cooled at constant pressure is 3.98 L
Explanation:
The new volume is calculated using the Charles law formula
that is V1/ T1 = V2/T2 where,
V1 = 4.24 l
T1= 23c into kelvin = 23 +273 =296 K
T2 = 5.00 c into kelvin = 5.00 + 273 = 278 K
V2 = ?
by making V2 subject the subject of the formula by multiplying both side by T2
V2 = V1 xT2/ T1
V2 = (4.24 L x 278 K) / 296 k = 3.98 L
Answer:
(i) rusting is caused by the reaction of oxygen and water on the surface of metals(iron).
(ii) rusting of iron makes it weak and dangerous for buildings since their foundation is made of iron, rusting renders cars useless, rusting can cause accidents.
(iii) by galvanizing iron
and by coating it.
Explanation:
hope it helps .
The pressure increases if the volume decreases
