Chemical Reactions and Conservation of Mass

What is the Law of Conservation of Mass?

• Matter can be created or destroyed during chemical reactions

• Mass changes during physical changes but not chemical changes

• The total mass of the products is always less than the reactants

• Matter can NOT be created or destroyed during chemical reactions

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

In the chemical equation, 2H2​+O2​→2H2​O, what do the bold 2s represent?

• Products

• Coefficients

• Reactants

• Subscripts

What type of reaction is represented by AB→A+B?

• Single Replacement

• Synthesis

• Decomposition

• Double Replacement

In a Brønsted-Lowry acid-base reaction, what is the acid?

• Proton donor

• Electron donor

• Proton acceptor

• Electron acceptor

What is an example of a physical change?

• Rusting of iron

• Burning of wood

• Ice melting

• Milk souring

Tags

NGSS.MS-PS1-4

What is a precipitate?

• The liquid remaining after a reaction

• A dissolved substance

• An insoluble solid formed during a reaction

• A gaseous product

Tags

NGSS.MS-PS1-2

In the reaction AgNO3+NaCl→AgCl+NaNO3​, which compound is the precipitate?

• AgNO3

• NaCl

• AgCl

• NaNO3

Tags

NGSS.MS-PS1-2

A monoprotic acid...

• Can donate multiple protons

• Can donate only one proton

• Cannot donate protons

• Always form two products

Which type of reaction is CH4+2O2→CO2​+2H2​O?

• Single replacement

• Double replacement

• Synthesis

• Combustion

What is a reactant?

• The ending material in a reaction

• The starting material in a reaction

• The catalyst

• The precipitate formed

Tags

NGSS.MS-PS1-2