<span>If we use 100 mL of
solution:
V(ethylene glycol - C</span>₂H₆O₂) = 0,52 · 100 mL = 52 mL.<span>
V(water) = 0,48 · 100 mL = 48 mL.
m(C</span>₂H₆O₂) = 52 mL · 1,115 g/mL = 57,98 g.<span>
n(C</span>₂H₆O₂) = 57,98 g ÷ 62,07 g/mol = 0,934 mol.<span>
m(H</span>₂O)
= 48 mL · 0,988 g/mL = 47,424 g.<span>
n(H</span>₂O)
= 45,45 g ÷ 18 g/mol = 2,635 mol.<span>
mole fraction of solvent: 2,635 mol / (2,635 mol
+ 0,934 mol) =0,73.
Raoult's Law: p(solution) = mole fraction of
solvent · p(solvent).
<span>p(solution) = 0,73 · 92 torr = 67,33 torr.</span></span>
Answer :
V - mass of the water in the calorimeter
V - mass of the metal
V - change in temperature of the water
V - change in temperature of the metal
C - volume of water in calorimeter
C - calorimeter pressure
C - specific heat of water
Explanation :
Variables : It is a factor that changes during the experiment or calculation.
Constant : It is a factor that does not change during the experiment or calculation.
In a calorimeter, the heat absorbed is equal to the heat released.
As we know that,
![m_1\times c_1\times \Delta T_1=-[m_2\times c_2\times \Delta T_2]](https://tex.z-dn.net/?f=m_1%5Ctimes%20c_1%5Ctimes%20%5CDelta%20T_1%3D-%5Bm_2%5Ctimes%20c_2%5Ctimes%20%5CDelta%20T_2%5D)
where,
= mass of water in calorimeter
= mass of metal
= change in temperature of the water
= change in temperature of the metal
= specific heat of water
= specific heat of metal
From this, we conclude that the value of specific heat of water is constant while the other are variables.
The volume of water in calorimeter, calorimeter pressure is also constant.
The correct option is C.
A Lewis dot diagram is a representation of the valence electron of an atom, which uses dot around the symbol of the atom. Chlorine has seven electrons in its outermost shell, these seven electrons are arranged in form of dot around the atom of chlorine. If you count the number of dot given in option C, you will notice that they are seven.
On temperature 25°C (298,15K) and pressure of 1 atm each gas has same amount of substance:
n(gas) = p·V ÷ R·T = 1 atm · 20L ÷ <span>0,082 L</span>·<span>atm/K</span>·<span>mol </span>· 298,15 K
n(gas) = 0,82 mol.
1) m(He) = 0,82 mol · 4 g/mol = 3,28 g.
d(He) = 10 g + 3,28 g ÷ 20 L = 0,664 g/L.
2) m(Ne) = 0,82 mol · 20,17 g/mol = 16,53 g.
d(Ne) = 26,53 g ÷ 20 L = 1,27 g/L.
3) m(CO) = 0,82 mol ·28 g/mol = 22,96 g.
d(CO) = 32,96 g ÷ 20L = 1,648 g/L.
4) m(NO) = 0,82 mol ·30 g/mol = 24,6 g.
d(NO) = 34,6 g ÷ 20 L = 1,73 g/L.
The two strands must be separated like the two sides of a zipper, by breaking the weak hydrogen bonds that link the paired bases.
<u>Explanation:</u>
- A double helix structure formed by two polypeptide chains is separated like the two sides of a zipper. A zipper is formed by breaking the weak hydrogen bonds that link the paired bases. During replication, an enzyme "Helicase" travels down the DNA and splits the chain and it forms 2 separate strands.
- The two DNA strand which has the same sequence must be separated like the two sides of a zipper by breaking weak hydrogen bases. During base pair-rule, the strand are unzipped and each strands is copied.
