Answer:
Explanation:
We will need a balanced equation with moles, so let's gather all the information in one place.
CH₃C₆H₄NH₂·HCl + (CH₃CO)₂O ⟶ CH₃C₆H₄NHCOCH₃ + junk
V/mL: 70.
c/mol·L⁻¹: 0.167
For simplicity in writing , let's call p-toluidine hydrochloride A and N-acetyl-<em>p</em>-toluidine B.
The equation is then
A + Ac₂O ⟶ B + junk
1. Moles of A

2. Moles of B
The molar ratio is 1 mol B:1 mol A
Moles of B = moles of A = 12 mmol = 0.012 mol

Answer:
86.3 g of N₂ are in the room
Explanation:
First of all we need the pressure from the N₂ in order to apply the Ideal Gases Law and determine, the moles of gas that are contained in the room.
We apply the mole fraction:
Mole fraction N₂ = N₂ pressure / Total pressure
0.78 . 1 atm = 0.78 atm → N₂ pressure
Room temperature → 20°C → 20°C + 273 = 293K
Let's replace data: 0.78 atm . 95L = n . 0.082 . 293K
(0.78 atm . 95L) /0.082 . 293K = n
3.08 moles = n
Let's convert the moles to mass → 3.08 mol . 28g /1mol = 86.3 g
Remember that a cation will be smaller than its neutral atom, and an anion will be larger than its neutral atom. This would automatically eliminate answer choices A and D.
Also keep in mind that atomic radii decreases from left to right as you move along a periodic table. It also decreases from bottom up.
Atomic radii increases as you move from right to left and as you go from up to down.
As bromine is higher up in the periodic table than Iodine, it would have a smaller radius. Iodine would have a larger radius.
The correct answer is B. Br
Because the calcium ion donates two electrons to achieve the stable state. So the layer of electrons decrease form 4 layers(2,8,8,2) to 3 layers(2,8,8). Thus, the radius of a calcium ion is smaller than a calcium atom.