During an acid/base titration, Timothy was using a burette. In order to determine the volume of titrant added, Timothy needed to read and record the initial burette reading before beginning the titration and the final reading after reaching the end point of the titration. While recording these measurements, Tom was incorrectly reading the top of the meniscus. Will this systematic error influence his result? Why or why not?

The answer to the question is

The error due to taking measurement from the top will lead to an overestimation of the reagent by up to  0.08 cm³ where the maximum error in each measurement of a burette is 0.5 cm³, therefore the error is within acceptable limits.

Explanation:

The meniscus of the liquid is the shape of the surface of a liquid as observed when the liquid is in narrow container such as in a burret. The shape of the meniscusis due to the effect of surface tension.

When taking measurements from a burette, it is important that the eye should be at the same level as that of the meniscus with the reading taking from the bottom of the meniscus

The error of reading from the top of the burette instead of the bottom is a form of parallax error

The maximum error allowed in burette measurement is 0.05 cm³ while the error of reading from the top leads to an error of 19.70 -  19.62 = -0.08 l which is equivalent to -0.08 cm³

The error is within the acceptable limits but it could be larger and impact on the results of experiments as there would be

1. Less reagent to complete a chemical reaction

2. Different rate of reaction

3. Wastage of reagents

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.