Chemical Analysis

Q1: Which of the following is not an example of qualitative chemical analysis?

• Determining the concentration of a compound in a solution

• Identifying the anionic groups in a compound

• Identifying the functional group in a molecule

• Determining the elemental composition of a molecule

Chemical analysis can be split into two types: qualitative and quantitative. Which statement best describes the difference between them?

• Qualitative analysis aims to identify the composition of a substance, whereas quantitative analysis aims to determine the mass, percentage composition, or concentration of a substance.

• Qualitative analysis can be used to identify the cation in a compound, whereas qualitative analysis can be used to identify the anion in a compound.

• Qualitative analysis aims to identify the chemical properties of a substance, whereas quantitative analysis aims to identify the physical properties.

• Qualitative analysis aims to determine the mass, percentage composition, or concentration of a substance, whereas quantitative analysis aims to identify the composition of a substance.

Chemical analysis can be used to determine the amount of glucose present in a person. In which scientific field is this analysis important?

• Environmental

• Industrial

• Medical

• Food chemistry

For each of the following anions, which statement best describes the experimental procedure used to test for it?

A sulfite anion

• Adding an equal volume of dilute HCl

  ,followed by heating, which results in production of a gas that turns filter paper soaked in acidified aqueous K2Cr2O7

  from orange to green.

• Adding an equal volume of dilute NaOH

  ,followed by heating, which results in production of a gas that turns moist litmus paper blue

• Adding an aqueous ammonia solution, which produces a yellow precipitate

• Adding an equal volume of dilute nitric acid, followed by silver nitrate, which gives a white precipitate

For each of the following anions, which statement best describes the experimental procedure used to test for it?A carbonate anion

• Adding dilute NaOH

  ,which results in production of a gas that relights a glowing splint

• Adding an equal volume of dilute nitric acid, followed by silver nitrate, which gives a white precipitate

• Adding an aqueous ammonia solution, which produces a green precipitate

• Adding dilute hydrochloric acid, which results in production of a gas that turns limewater cloudy

The image shows a series of tests carried out on an unknown sodium salt, What formula is the unknown sodium salt likely to have?

• Na3PO4

• NaHCO3

• Na2S

• Na2S2O3

Tags

NGSS.HS-PS1-3

Which of the solutions of sodium salts shown will not produce a gas when reacted with dilute aqueous HCl?

• A

• B

• C

• D

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

A scientist wants to check for the presence of bicarbonate anions. They perform the following experiment:

• Na2CO3

• Na2O

• Mg(HCO3)2

• MgCO3

When a student adds a dilute hydrochloric acid to a sample of sodium sulfite to detect the sulfite ion, a colorless gas with a very irritating odor is evolved.What is the name of this gas?

• Sulfur dioxide gas

• Hydrogen gas

• Sulfur monoxide gas

• Hydrogen sulfide gas

A student is given five unknown solutions (A–E) and told they are sodium salts. The student only has dilute HCl

,some AgNO3

available, and no other lab equipment. The student adds dilute HCl

to one sample of each solution, and they add AgNO3

to a different sample. The table below lists the observations seen for each reaction.

Which solution is likely to contain NaNO2?

• A

• B

• C

• D

• E

Tags

NGSS.HS-PS1-3