Chemical Reactions

A substance that enters into a chemical reaction is called a

• mole.

• product.

• coefficient.

• reactant.

In a reaction in which hydrogen reacts with oxygen to produce water, which substances are the reactants?

• hydrogen only

• oxygen only

• both hydrogen and oxygen

• water

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

Which of the following is not an example of a chemical change?

• rusting iron

• an apple ripening

• cutting paper

• a piece of wood burning

Tags

NGSS.MS-PS1-2

In a chemical reaction, what is the relationship between the total mass of the reactants and the total mass of the products?

• They must be equal.

• The mass of the products must be greater.

• The mass of the reactants must be greater.

• There is no general relationship between the two.

Tags

NGSS.MS-PS1-5

What is the general form for a single-replacement reaction?

• AX + BY --> AY + BX

• AB --> A + B

• A + B --> AB

• A + BX --> AX + B

What is the general form for a double-replacement reaction?

• AX + BY --> AY + BX

• AB --> A + B

• A + B --> AB

• A + BX --> AX + B

What kind of reaction is represented by the equation C₂Cl₄ + Cl₂ --> C₂Cl₆?

• synthesis

• double replacement

• single replacement

• combustion

According to the law of conservation of mass, the total mass of the reacting substances is

• always more than the total mass of the products.

• always less than the total mass of the products.

• sometimes more and sometimes less than the total mass of the products.

• always equal to the total mass of the products.

Tags

NGSS.MS-PS1-5

The reaction 2Mg + O₂ --> 2MgO is a

• synthesis reaction.

• decomposition reaction.

• single-replacement reaction.

• double-replacement reaction.

The reaction Mg + 2HCl --> H₂ + MgCl₂ is a

• composition reaction.

• decomposition reaction.

• single-replacement reaction.

• double-replacement reaction.