24.3.2 Phosphorus

Question 1

Which of the following best describes the role of trisodium phosphate (“TSP”) as an ingredient in laundry or dishwashing detergent?

Answer 1

Controls pH and precipitates calcium and magnesium ions out of solution

Question 2

Which of the following categories of phosphorus compounds contains a mistake?

Answer 2

phosphorus halides: PF3, PCl3, PBr3, PBr4, PCl5

Question 3

Which compound contains phosphorus in the +3 oxidation state?

Answer 3

H3PO3

Question 4

Which of the reactions of phosphorus compounds below represents that of an unbalanced equation?

Answer 4

P4S3 + KClO3 + O2 → P4O10 + SO2 + KCl

Question 5

Which of the following applications of group 15 elements is not correctly matched to the appropriate element(s)?

Answer 5

light-emitting diode / bismuth

Question 6

Phosphorus is most commonly found in nature as:

Answer 6

Phosphate rock

Question 7

Which of the following Group 15 (VA) elements is NEVER found uncombined in nature?

Answer 7

P

Question 8

Which of these phosphorus compounds is mismatched with its name?

Answer 8

C: Tripolyphosphoric acid

Question 9

The formation and breaking of P–O bonds is used as energy currency in which of the following biological molecules?

Answer 9

ATP

Question 10

Many laundry detergents are labeled as being “phosphate free.” If phosphorus compounds such as TSP make good “builders”, why would these chemicals be removed from consumer products such as detergents?

Answer 10

They can cause algal blooms, rapidly depleting water of O2.