Answer:
(a) Ethyl acetate and hexane, and (c) methanol and methylene chloride.
Explanation:
re-crystallization is a technique used to purify solid compound. Ethyl acetate and hexane are good solvent pair for recrystallization because they are miscible with each other due to their good differences in polarity. ethyl acetate has polarity of 77 while hexane has 68.
water and diethyl ether are not good solvent pair for recrystallization because water and diethyl ether are immiscible. They have very far polarity values. water has 100 while diethyl ether has 35
election circles the nucleus
The number of oxygen atoms are 6 atoms
<u><em>Explanation</em></u>
According to the law of mass conservation the number of reactant atoms is equal to number of product atoms.
For given equation to obey the law of mass conservation it need to be balanced as below
4 Al + 3 O₂ → 2 Al₂O₃
Al₂O₃ is the product,therefore the number of oxygen atom
= coefficient in front of Al₂O₃ × subscript of O
=2 x 3 = 6 atoms
Answer:
1. get vitamin c
2. get your bone mineral density tested
3. don't smoke or drink excessively
4. start weight-bearing exercise
Explanation:
helps improve skeletal system
Answer:
P₂ = 20.5 torr
Explanation:
Given data:
Volume of tank = 15.0 L
Pressure of tank = 8.20×10⁴ torr
Final volume of tank = 6.00×10⁴ L
Final pressure = ?
Solution:
The given problem will be solved through the Boly's law,
"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"
Mathematical expression:
P₁V₁ = P₂V₂
P₁ = Initial pressure
V₁ = initial volume
P₂ = final pressure
V₂ = final volume
Now we will put the values in formula,
P₁V₁ = P₂V₂
8.20×10⁴ torr × 15.0 L = P₂ × 6.00×10⁴ L
P₂ = 8.20×10⁴ torr × 15.0 L / 6.00×10⁴ L
P₂ = 123×10⁴ torr.L/ 6.00×10⁴ L
P₂ = 20.5 torr