<span>You use the Henderson - Hasselbalch equation
pH = pKa + log ([salt]/[acid])
pKa = -log (8.2*10^-5) = 4.081
pH = 4.081 + (0.590/0.190)
pH = 4.081 + log 3.105
pH = 4.081 + 0.49206
pH = 4.573</span>
Answer:
Option C
CH₃CH₂CH₂COOH
Explanation:
Carbonxylic acids are compounds which has the general formula
R–COOH where R is an alkyl group.
Considering the options given in the question above,
For A:
CH₃CH₂OCH₂CH₃ is an ether compound with general formula ROR' where R and R' are both alkyl group.
For B:
CH₃CH₂CH₂CH₂OH is an alcohol with general formula ROH where R is an alkyl group.
For C:
CH₃CH₂CH₂COOH is a carbonxylic acid with general formula R–COOH where R is an alkyl group.
For D:
CH₃CH₂C=OCH₂CH₃ is a ketone compound with general formula RC=OR' where R and R' are both alkyl group
For E:
ClCH₂CH₂CH₂CH₂CH₂CH₂Br is simply an Alkyl halide with general formula XRX where X is an halogen (i.e F, Cl, Br or I) and R is an alkyl group.
From the above illustration, only option C contains a Carbonxylic compound.
Answer: Hydrogen molecules will have greatest average speed.
Explanation:
The formula for average speed is :

R = gas constant
T = temperature
M = Molecular Mass
Now putting all the values:



Thus average speed of hydrogen is 8 times the average speed of oxygen. Thus hydrogen molecules will have greatest average speed
The least net force applied : Car 3(12 N)
<h3>Further explanation </h3>
Newton's 2nd law explains that the acceleration produced by the resultant force on an object is proportional and in line with the resultant force and inversely proportional to the mass of the object
∑F = m. a
Car 1 ⇒m=0.5 kg, a=36 m/s²

Car 2⇒m=0.8 kg, a=50 m/s²

Car 3⇒m=0.6, a=20 m/s²

Car 4⇒m=1, a=19~m/s²

Answer:
B) number of electrons
Explanation:
The two species:
K+ and Cl- have the same number of electrons.
A neutral atom of K has 19 electrons
A neutral atom of Cl has 17 electrons
Now,
To form K+, K will have to lose an electron and then the number of electrons becomes 18
To form Cl-, Cl will have to gain an electrons and then the number of electrons becomes 18
So, therefore, the number of electrons on both species is 18