The answer is H₃C₆H₅O₇ (OPTION D).
In essence, the question is asking which of the options is an acid or a neutral compound; thus not a base. A base is a compound that accepts free hydrogen ions while in aqueous solution and as such they usually lack hydrogen ions that can be released in solution. If you ionize all the compounds/molecules above, the only on that has free hydrogen ions is OPTION D (which is an organic acid and not a base).
The answer is: II.The endpoint is recorded when the solution is dark red in color rather than light pink.
The endpoint is the point at which the indicator changes colour in a colourimetric titration and that is point when titration must stop.
Phenolphthalein is colorless in acidic solutions and pink in basic solutions. If this indicator change color to dark red, more base is added and endpoint is not accurate.
If the the acid is spilled before titration, that does not make endpoint wrong and molar mass can be calculated.
In this example we can take acetic acid as carboxylic acid; basic salt sodium acetate CH₃COONa is formed from the reaction between weak acid (in this example acetic acid CH₃COOH) and strong base (in this example sodium acetate NaOH).
Balanced chemical reaction of acetic acid and sodium hydroxide:
CH₃COOH(aq) + NaOH(aq) → CH₃COONa(aq) + H₂O(l).
Neutralization is is reaction in which an acid (in this example vinegar or acetic acid CH₃COOH) and a base react quantitatively with each other.
Number of moles = mass of product / molecular mass
=mass of product (MgO) / 40.3
Since the mass of MgO is not given in the question, the correct answer choice cannot be given. However, proceeding witht eh above formula will enable you to find the correct number of moles given the mass of MgO.
<h2>Collision Theory
</h2>
Explanation:
<h3>
The given statement is related to the collision theory -
</h3>
Collision theory was given by William Lewis in 1916.
This theory explains in a qualitative manner that in what way any chemical reaction occurs and the reason for the different reaction rates for different reactions.
<h3>
According to the collision theory -
</h3>
- Molecules must collide in order to react
- Sufficient amount of energy is needed for collisions (kinetic energy) so that the chemical bonds should break
- This energy used is known as the activation energy
- On the increase in the temperature, the kinetic energy of the molecule increases and the molecules move faster and collide with a proper orientation at an increased speed
- This increases the rate of a collision that in turn increases the breaking of the bond
Missing in your question:
Picture (1)
when its an open- tube manometer and the h = 52 cm.
when the pressure of the atmosphere is equal the pressure of the gas plus the pressure from the mercury column 52 Cm so, we can get the pressure of the gas from this formula:
P(atm) = P(gas) + height (Hg)
∴P(gas) = P(atm) - height (Hg)
= 0.975 - (520/760)
= 0.29 atm
Note: I have divided 520 mm Hg by 760 to convert it to atm
Picture (2)
The pressure of the gas is the pressure experts by the column of mercury and when we have the Height (Hg)= 67mm
So the pressure of the gas =P(atm) + Height (Hg)
= 0.975 + (67/ 760) = 1.06 atm
Picture (3)
As the tube is closed SO here the pressure of the gas is equal the height of the mercury column, and when we have the height (Hg) = 103 mm. so, we can get the P(gas) from this formula:
P(gas) = Height(Hg)
= (103/760) = 0.136 atm
