Naming Hydrates and Covalent Compounds and Acids

Name the following ionic compound: MgSO₄*7H₂O

• magnesium sulfate * hexahydarte

• magnesium sulfate hexahydarte

• magnesium sulfate heptahydrate

• magnesium sulfate* heptahydrate

Answer explanation

The correct answer is 'magnesium sulfate heptahydrate'. The compound MgSO4*7H2O is named based on its components: 'magnesium' for Mg, 'sulfate' for SO4, and 'heptahydrate' for the 7 water molecules (H2O). The prefix 'hepta-' indicates seven in chemical nomenclature.

Na₂CO₃ · 10H₂O is known as sodium carbonate ______

• Hydroxide

• Hydrate

• Decahydrate

• None of the above

Answer explanation

The compound Na2CO3 · 10H2O is known as Sodium Carbonate Decahydrate. The term 'Decahydrate' refers to the ten water molecules that are part of the compound's structure. The other options, 'Hydroxide', 'Hydrate', and 'None of the above' are incorrect in this context.

Name the following hydrate:  NaCl * 5H₂O

• sodium chloride 

• sodium monochloride pentahydrate

• sodium chloride pentahydrate

• pentahydrate

Answer explanation

The question asks for the name of the hydrate NaCl * 5H2O. The correct answer is 'sodium chloride pentahydrate'. The term 'pentahydrate' refers to the five water molecules (H2O) that are combined with the sodium chloride (NaCl). The other options do not accurately represent the chemical composition of the hydrate.

A compound is a hydrate when it...

• is composed of only hydrogen and oxygen

• is a state of water

• traps water inside of the compound

• repels water from the compound

Answer explanation

A compound is considered a hydrate when it traps water inside of the compound. This occurs when water molecules are incorporated into the crystal structure of the compound, forming a new substance with a specific ratio of water molecules to the original compound.

What is the correct formula for Sodium Oxide Trihydrate?

• NaO * 3H₂O

• NaO₂ * 5H₂O

• Na₂O * 3H₂O

• Na₂O₂ * 5H₂O

Answer explanation

The correct formula for Sodium Oxide Trihydrate is Na2O * 3H2O. Sodium oxide has the chemical formula Na2O, and trihydrate indicates that there are three water molecules (H2O) associated with each formula unit. Therefore, the correct option is Na2O * 3H2O.

Which of the following shows Magnesium Chloride Hexahydrate?

• MgCl₂ · 12H₂O

• MgCl₂ · 11H₂O

• MgCl₂ · 6H₂O

• MgCl₂ · 13H₂O

Answer explanation

Magnesium Chloride Hexahydrate is represented by the chemical formula MgCl2 · 6H2O. The 'hexa' in hexahydrate indicates that there are six water molecules (H2O) associated with each magnesium chloride (MgCl2) unit. Among the given options, MgCl2 · 6H2O correctly represents Magnesium Chloride Hexahydrate.

carbonic acid

• H₂CO₃

• H₂CrO₄

• H₂C₂O₄

• HCO₃

Answer explanation

Carbonic acid is a weak acid formed when carbon dioxide dissolves in water. Its chemical formula is H2CO3. Among the given options, H2CO3 is the correct representation of carbonic acid, while the other options represent different chemical compounds.

Tags

NGSS.HS-PS1-4

H₃PO₄

• hydrophsophorus acid

• phosphoric acid

• hydrogen phosphorous

• phosphori hydroxide

Answer explanation

H3PO4 is the chemical formula for phosphoric acid. The correct choice is phosphoric acid because it represents the compound formed by three hydrogen atoms, one phosphorus atom, and four oxygen atoms. The other options, hydrophosphorus acid, hydrogen phosphorous, and phosphori hydroxide, do not correctly represent the chemical formula H3PO4.

Name this acid: H₂SO₄

• hydrogen sulfate

• hydrosulfuric acid

• sulfuric acid

• sulfurous acid

Answer explanation

H2SO4 is the chemical formula for sulfuric acid. It consists of two hydrogen atoms, one sulfur atom, and four oxygen atoms. The correct option is sulfuric acid, as it accurately represents the composition of this strong acid.

What element do all acids contain?

• H

• O

• C

• He

Answer explanation

All acids contain the element Hydrogen (H). This is because acids are substances that donate a proton or accept an electron pair in reactions. The presence of Hydrogen is what allows them to do this. Therefore, the correct answer to the question 'What element do all acids contain?' is 'H'.