PS midterm

Which compound is most likely formed using covalent bonds?

• SiO₂

• K₂O

• KBr

• CaBr₂

Tags

NGSS.MS-PS1-1

A teacher demonstrates a combustion reaction. Which would be a correct demonstration?

• Burning magnesium in the presence of oxygen to produce magnesium oxide

• Burning methane in the presence of oxygen to produce carbon dioxide and water

• Running an electrical current through water to produce hydrogen and oxygen

• Reacting iron with oxygen to produce iron oxide

Tags

NGSS.MS-PS1-5

NGSS.MS-PS1-2

Which equation represents a double replacement reaction?

• 2KClO₃ → 2KCl + 3O₂

• CaBr₂ + Na₂CO₃ → CaCO₃ + 2NaBr

• Zn + S → ZnS

• 2Li + FeBr₂ → 2LiBr + Fe

Which compound is formed when aluminum bonds with fluorine?

• AlF

• AlF₂

• AlF₃

• Al₃F

Tags

NGSS.MS-PS1-1

A chemical reaction is represented by this equation: 2Fe₂O₃ → 4Fe + 3O₂. What is a product of this chemical reaction?

• FeO

• F

• O₂

• Fe₂O₃

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

Which is a correctly balanced chemical equation?

• K₂CO₃ + BaCl₂ → KCl + BaCO₃

• K₂CO₃ + BaCl₂ → 2KCl + BaCO₃

• K₂CO₃ + 2BaCl₂ → 2KCl + BaCO₃

• K₂CO₃ + 2BaCl₂ → KCl + 2BaCO₃

Tags

NGSS.MS-PS1-5

The reaction of CaO and water is exothermic. A student mixes the two chemicals in a test tube and touches the side of the tube. Which statement describes the student’s observation?

• The test tube becomes hot as heat is released during the reaction

• The test tube becomes hot as heat is absorbed during the reaction

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-3

Solutions of lead nitrate and potassium dichromate are mixed. The solution turns cloudy and yellow. Solid yellow particles fall to the bottom of the beaker. Which statement best describes this reaction?

• A precipitate formed

• A gas formed

• The reaction is exothermic

• The reaction is endothermic

Tags

NGSS.MS-PS1-2

The diagram above shows a chemical equation with the substances on either side of the equation hidden from view. From the Law of Conservation of Matter, we know that:

• The products must weigh more than the reactants

• Energy is neither absorbed or released by the reaction

• The substances on either side of the equation must be the same

• The number of atoms on either side of the equation must be the same

Tags

NGSS.MS-PS1-5

Which is the formula for the compound that forms when magnesium bonds with phosphorus?

• Mg₂P

• Mg₃P₂

• Mg₂P₃

• Mg₃P

Tags

NGSS.MS-PS1-1