Answer:
T = 100.63 °C
Explanation:
To solve this question, we need to know what are we talking about here. In this case, we want to know the boiling point of a solution with Urea in water. This is a colligative property, so, the expression to use to calculate that is the following:
ΔT = m * K / MM * kg water (1)
Where:
ΔT: difference of temperatures (Tb of solution - Tb water)
m: mass of the urea
K: ebulloscopic constant of the water (0.52 ° C / m)
MM: molecular mass of urea
The boiling point of water is 100 °C, we have the mass of the urea, but not the molar mass. The urea has the formula CH₄N₂O, so the molar mass can be calculated using the atomic mass of the elements (I will use a rounded number for this):
MM = 12 + (4*1) + (2*14) + 16 = 60 g/mol
Now, we can calculate the ΔT and then, the boiling point of the solution:
ΔT = 12 * 0.52 / 60 * 0.165
ΔT = 6.24 / 9.9
ΔT = 0.63 °C
the value of ΔT is a difference between the boling point of water and the solution so:
ΔT = Ts - Tw
Ts = ΔT + Tw
Replacing we have:
Ts = 100 + 0.63
<h2>
Ts = 100.63 ° C</h2>
PV = nRT
Pressure times volume = number of moles times ideal gas constant times temperature
50mL = .05L
1 atm (.05) = n (.0821) (273)
.05 = n (22.4133)
.022 = n (number of moles)
6.022E23 molecules = 1 mole
.022 x 6.022E23 = 1.325E23 molecules
PH of a solution will be <span>higher than 7
</span>
Ammonium cyanide is a salt formed by hydrogen cyanide and ammonia. Ammonia is a weak base and hydrogen cyanide is a weak acid.
NH₄CN + H₂O ⇒ NH₃ + HCN
NH₄⁺ + H₂O -----> H₃O⁺ + NH₃
CN⁻ + H₂O -----> HCN + OH⁻
Although both compounds are weak electrolytes, NH₃ is somewhat stronger base than HCN is a strong acid, so the solution reacts alkaline. We can prove this using Ka and Kb values:
Ka(HCN) = 4.9 x × 10⁻¹⁰
Kb(NH₃) = 1.8 × 10⁻⁵<span>
Kw= </span>1.0 × 10⁻¹⁴
Let's first calculate Ka for NH₄⁺:
Ka(NH₄⁺) x Kb(NH₃<span>) = pKw
</span>Ka(NH₄⁺) = Kw/Kb(NH₃) = 5.6 x 10⁻¹⁰
Then, Kb for CN⁻:
Kb(CN⁻) x Ka(HCN) = pKw
Kb(CN⁻) = Kw/Ka(HCN) = 2 x 10⁻⁵
From this, we can see that the acid constant NH4⁺ is much lower than the base constant of CN⁻, which will say that the solution of NH₄CN will react slightly alkaline because of the higher presence of hydroxyl ions in solution.
Answer:
<u>True</u>
Explanation:
|ndeed, Psychologist Abraham Maslow's sought to describe hierarchy in which the average (or most) humans place their needs. In other words, he believes we as humans have basic needs which we long to satisfy.
On the ranking or hierarchy, according to Maslow the need humans satisfy first is their physiological need. Here's the full hierarchy:
Physiological Needs
↓
Safety Needs
↓
Love/Belonging Needs
↓
Esteem Needs
↓
Self-Actualization
Answer:
4.85 x 10^25
Explanation:
thats what i was told by a calculator
