6= Only the digits 1 and 6 are the actual measured values. Therefore we have only 2 significant figures.
0.3= Zeros used as placeholders are not significant. Zeros that come before non-zero integers are never significant. Example 5: The zeros in 098, 0.3, and 0.000000000389 are not significant because they are all in front of non-zero integers. c. If the zeros come after non-zero integers and are followed by a decimal point, the zeros are significant.
This is because amino group of p-aminobenzoic acid is an aniline and is less electrophilic than an alkyl amine.
<h3>What is an Aniline?</h3>
This is an aromatic amine which consists of a phenyl group attached to an amino group.
The amino group of p-aminobenzoic acid being an aniline makes it less electrophilic which is why an alkyl amine participates in the reaction instead.
Read more about Aniline here brainly.com/question/9982058
Rate law for the given 2nd order reaction is:
Rate = k[a]2
Given data:
rate constant k = 0.150 m-1s-1
initial concentration, [a] = 0.250 M
reaction time, t = 5.00 min = 5.00 min * 60 s/s = 300 s
To determine:
Concentration at time t = 300 s i.e. ![[a]_{t}](https://tex.z-dn.net/?f=%5Ba%5D_%7Bt%7D)
Calculations:
The second order rate equation is:
![1/[a]_{t} = kt +1/[a]](https://tex.z-dn.net/?f=1%2F%5Ba%5D_%7Bt%7D%20%3D%20kt%20%2B1%2F%5Ba%5D)
substituting for k,t and [a] we get:
1/[a]t = 0.150 M-1s-1 * 300 s + 1/[0.250]M
1/[a]t = 49 M-1
[a]t = 1/49 M-1 = 0.0204 M
Hence the concentration of 'a' after t = 5min is 0.020 M
<span><u><em>Answer:</em></u>
All of the above
<u><em>Explanation:</em></u>
Vertebrates are a class of creatures falling under kingdom "<u>Animalia</u>" that are characterized by the presence of an internal skeleton composed of bones.
<u>Vertebrates are characterized by the following:</u>
1- presence of internal skeleton
2- developed brain
3- the presence of an advanced nervous system connected to the brain
4- presence of muscles that allow movement
5- protective skin
6- circulation of blood in the bodies in the vessels
Comparing the mentioned characteristics with the options given, we will find that the most suitable answer is: <u>"all of the above"</u>.
Hope this helps :)</span>
Answer:
Option B, HCO3 1-
Explanation:
The valence of Sodium ion is +1 and the valence of HCO3 is -1. Thus, sodium ion has an extra electron to be donated to complete its outer shell while HCO3 needs an electron to complete its outer shell
Hence Na will combine with HCO3 to form NaHCO3
Option B is correct
