Electron affinity is a measure of the tendency of a neutral atom to gain electrons and form a negative ion. It can be represented by a general equation:
X + e- → X-
The value of electron affinity decreases on moving down a group. This is because on moving down a group the atomic size increases as a result the added electron feels less pull or attraction towards the nucleus.
In group 14, Carbon 'C' is the first member and therefore will have the highest electron affinity.
Ans : A) Carbon
Volume of each solution : 60 ml 20% and 40 ml 45%
<h3>Further explanation</h3>
Given
20% and 45% acid
100 ml of 30% acid
Required
Volume of each solution
Solution
Molarity from 2 solutions :
Vm Mm = V₁. M₁ + V₂. M₂
m = mixed solution
V = volume
M = molarity
V₁ = x ml
V₂ = (100 - x) ml
Input the value :
100 . 0.3 = x . 0.2 + (100-x) . 0.45
30 = 0.2x+45-0.45x
0.25x=15
x= 60 ml
V₁ = 60 ml
V₂ = 100 - 60 = 40 ml
Answer: one simple distillation column is required to separate the stream into five pure products. With four different flat bottom flask, for collection of the distilled products
Explanation: simple distillation works with the difference in boiling points of the liquid to be separated. For the separation of five different constituent to be possible, we have to know the boiling points of the constituents.
For your understanding, let's define constituents in the liquid to be A, B, C, D, E. And the boiling points increases respectively. Start by heating the liquid to the boiling point of A to extract A. After a while check if the constituents A is still dropping in the flat bottom flask, if it has stopped dropping, it simply means that we have extracted all A constituents in the liquid, label the Flask A. Get another flask to extract constituent B.
Heat the mixture to the boiling point of B, after a while check if constituent B is still dropping in the flat bottom flask, if it has stopped dropping,it means that we have extracted all B constituent in the liquid, label the Flask B. Get another flask for C.
Repeat the same process for C and D.
After Extracting D we don't need to distillate E because we already have a pure form of E inside to the conical flask.
SEE PICTURE TO UNDERSTAND WHAT A SIMPLE DISTILLATION LOOKS LIKE
<h3><u>Answer</u>;</h3>
= 4.68 K
<h3><u>Explanation</u>;</h3>
According to the combined gas law;
P1V1/T1 = P2V2/T2
Given; P1 = 125 Psi
V1 = 75 L
T1 = 288 K
P2 = 25 PSI
V2 =6.1 L
Therefore;
T2 = P2V2T1/P1V1
= (25×6.1 ×288)/(125×75)
= 4.6848
= 4.68 K
Coulomb's law mathematically is:
F = kQ₁Q₂/r²
we integrate this with respect to distance to obtain the expression for energy:
E = kQ₁Q₂/r; where k is the Coulomb's constant = 9 x 10⁹; Q are the charges, r is the seperation
Charge on proton = charge on electron = 1.6 x 10⁻¹⁹ C
E = (9 x 10⁹ x 1.6 x 10⁻¹⁹ x 1.6 x 10⁻¹⁹) / (185 x 10⁻¹²)
E = 1.24 x 10⁻¹⁸ Joules per proton/electron pair
Number of pairs in one mole = 6.02 x 10²³
Energy = 6.02 x 10²³ x 1.24 x 10⁻¹⁸
= 746.5 kJ