Answer:
i = 2.483
Explanation:
The vapour pressure lowering formula is:
Pₐ = Xₐ×P⁰ₐ <em>(1)</em>
For electrolytes:
Pₐ = nH₂O / (nH₂O + inMgCl₂)×P⁰ₐ
Where:
Pₐ is vapor pressure of solution (<em>0.3624atm</em>), nH₂O are moles of water, nMgCl₂ are moles of MgCl₂, i is Van't Hoff Factor, Xₐ is mole fraction of solvent and P⁰ₐ is pressure of pure solvent (<em>0.3804atm</em>)
4.5701g of MgCl₂ are:
4.5701g ₓ (1mol / 95.211g) = 0.048000 moles
43.238g of water are:
43.238g ₓ (1mol / 18.015g) = 2.400 moles
Replacing in (1):
0.3624atm = 2,4mol / (2.4mol + i*0.048mol)×0.3804atm
0.3624atm / 0.3804atm = 2,4mol / (2.4mol + i*0.048mol)
2.4mol + i*0.048mol = 2.4mol / 0.9527
2.4mol + i*0.048mol = 2.5192mol
i*0.048mol = 2.5192mol - 2.4mol
i = 0.1192mol / 0.048mol
<em>i = 2.483</em>
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I hope it helps!
Q1. Chemical, Physical, Physical, Physical
(l am not 100% sure about the 4th answer)
Q2. All of the above
Answer: An electron will jump to a higher energy level when excited by an external energy gain such as a large heat increase or the presence of an electrical field, or collision with another electron.
Explanation:
A compound machine is that which is composed of two or more simple machines. Simple machines come in 6 basic types: (1) wheel and axle, (2) inclined plane, (3) wedge, (4) pulley, (5) screw, and (6) lever. Among the choices given above, the compound machine is the can opener for it is a combination of a wedge and a lever.
