Practice test Mastery for Unit 2

Astrid and Aubrey are in a chemistry lab, and they stumble upon a mysterious compound. Can you help them identify which of the following compounds contains the elusive lead (IV) ion?

• PbO

• PbCl4

• Pb2O

• Pb2S

Answer explanation

The lead (IV) ion, represented as Pb^4+, is found in PbCl4, where lead has a +4 oxidation state. PbO contains Pb^2+, Pb2O and Pb2S also contain lead in lower oxidation states, thus they do not contain lead (IV) ions.

Hey chemistry enthusiasts! Jada and Sebastian are having a debate. Can you help them out? What is the correct name for KMnO4?

• Potassium Manganese tetroxide

• Pomanganese Oxide

• Potassium permanganate

• Potassium phosphite

Answer explanation

The correct name for KMnO4 is Potassium permanganate. It consists of potassium (K) and the permanganate ion (MnO4), making this option the accurate chemical nomenclature.

Hey science enthusiasts! Trayce and Elias are having a debate. Can you help them figure out which of the following compounds doesn't belong to the nonpolar covalent bond club?

• F2

• N2

• HCl

• CO2

Answer explanation

HCl is polar due to the difference in electronegativity between hydrogen and chlorine, leading to a dipole moment. In contrast, F2, N2, and CO2 are nonpolar because they either consist of identical atoms or have symmetrical structures.

Madison and Leo are in a chemistry lab, and they stumble upon a mysterious compound labeled NH4ClO3. What would be the first name they should use for this compound?

• Nitrogen

• Ammonia

• Nitrogen tetrahydride

• Ammonium

Answer explanation

The compound NH4ClO3 contains the ammonium ion (NH4+). Therefore, the first name they should use for this compound is 'Ammonium', which correctly identifies the cation present in the formula.

Hey science whizzes! Hailey and Keira are having a friendly debate. Can you help them figure out which of the following chemical formulas is correct?

• Al2(SO4)2

• Na(ClO)3

• Na2O

• MgNO2

• K2PO3

Answer explanation

The correct formula is Na2O, which represents sodium oxide. The other options either have incorrect subscripts or do not represent valid compounds. Na2O is a stable and commonly known compound.

Jaquelin and Myles are exploring a mysterious formula, X3P. Can you help them figure out the charge of the unknown atoms in this intriguing compound?

• 2

• 1

• 4

• 3

Answer explanation

In the compound X3P, the subscript '3' indicates three atoms of element X. To balance the charge, each X atom must have a charge of +1, resulting in a total charge of +3. Therefore, the unknown atom's charge is 1.

Hey science whizzes! Cade and Jada are having a friendly debate. Can you help them figure out which pair below has the name and formula correctly matched?

• N2O2 is dinitrogen bioxide

• CaF2 is Calcium (II) difluoride

• P2Cl5 is phosphorus pentachloride

• SF6 is sulfur hexafluoride

Answer explanation

The correct match is SF6, which is sulfur hexafluoride. The other pairs are incorrect: N2O2 is dinitrogen dioxide, CaF2 is calcium fluoride, and P2Cl5 is phosphorus pentachloride.

Izzy and Max are in a chemistry lab, trying to figure out the correct formula for the compound formed between beryllium and phosphate. Can you help them solve this mystery?

• Be3(PO4)2

• Be3PO4

• Be2(PO4)3

• B3(PO4)2

Answer explanation

The correct formula for the compound formed between beryllium (Be) and phosphate (PO4) is Be3(PO4)2. This indicates that three beryllium ions combine with two phosphate ions to balance the charges.

Hey chemistry wizards! Autymn and Aiden are in a friendly debate. Can you help them figure out which of the following is the correct formula for hydrobromic acid?

• HBr

• HBrO3

• H2BO4

• H2Br

Answer explanation

The correct formula for hydrobromic acid is HBr. It consists of one hydrogen atom and one bromine atom, making it a simple binary acid. The other options do not represent hydrobromic acid.

Elle and Naomi are in a chemistry class, and they need your help! Can you figure out the correct formula for potassium sulfite?

• K2SO3

• KSO4

• P2SO3

• K2SO4

Answer explanation

Potassium sulfite consists of potassium (K) and sulfite (SO3). Each potassium ion has a +1 charge, and the sulfite ion has a -2 charge. To balance the charges, two potassium ions are needed, resulting in the formula K2SO3.