The answer should be A, the number of electrons increases by 1, from left to right.
Across the periods (horizontal direction) in periodic table, each element has one more electron then the one before it. The number of period determines the number of occupied electron shells of the elements in that period. Which means, period 1 elements have 1 occupied electron shell, period 2 has 2, period 3 has 3 etc.
Therefore, the answer is A, we always go from left to right, and plus since period 2 elements only have 2 occupied electrons so their 2nd electron shell electrons must increase throughout the period.
20 mL of an approximately 10% aqueous solution of ethylamine, CH3CH2NH2, is titrated with 0.3000 M aqueous HCl. Which indicator would be most suitable for this titration? The pKa of CH3CH2NH3+ is 10.75.
Answer:
Bromocresol green, color change from pH = 4.0 to 5.6
Explanation:
The equation for the reaction is as follows:
+ 
⇄ 
Given that concentration of = 10%
i.e 10 g of in 100 ml solution
molar mass = 45.08 g/mol
number of moles = 
= 0.222 mol
Molarity of = 0.222 × 
= 2.22 M
However, number of moles of in 20 mL can be determined as:
number of moles of = 20 mL × 2.22 M
= 
Concentration of = 
= 2.22 M
Similarly, The pKa Value of is given as 10.75
pKb value will be: 14 - pKa
= 14 - 10.75
= 3.25
Finally, the pH value at equivalence point is:
pH= ![\frac{1}{2}pKa - \frac{1}{2}pKb-\frac{1}{2}log[C]](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7DpKa%20-%20%5Cfrac%7B1%7D%7B2%7DpKb-%5Cfrac%7B1%7D%7B2%7Dlog%5BC%5D)
pH = ![\frac{14}{2}-\frac{3.25}{2}-\frac{1}{2}log [2.22]](https://tex.z-dn.net/?f=%5Cfrac%7B14%7D%7B2%7D-%5Cfrac%7B3.25%7D%7B2%7D-%5Cfrac%7B1%7D%7B2%7Dlog%20%5B2.22%5D)
pH = 5.21
∴
The indicator that is best fit for the given titration is Bromocresol Green Color change from pH between 4.0 to 5.6.
Answer:
propagation of disturbances—that is, deviations from a state of rest or equilibrium—from place to place in a regular and organized way. Most familiar are surface waves on water, but both sound and light travel as wavelike disturbances, and the motion of all subatomic particles exhibits wavelike properties.
Explanation:
<u>Answer:</u>
Shifts the equilibrium to side that has fewest moles of gas.
<u>Explanation</u>:
"Le Chatelier's principle", also called as the equilibrium law in chemistry explains the effect in different states on some chemical equilibria. It states that when a system is in equilibrium for a long time, it is subject to change in pressure, volume, temperature or condensation.
In this case, with an "increase" in pressure, there would be a shift to the side of fewer moles of gas. Mainly the change towards the reactants.
