Chemical Reactions

A substance that is formed as the result of a chemical reaction is a __________________

• Product

• Reactant

• Starters

• Enders

The Law of Conservation of Mass states that in a chemical reaction,

• mass of the reactants and mass of the products are equal

• new elements are formed

• new atoms are created

• atoms are destroyed

A change in the shape of an object is an example of _________________.

• a chemical change

• energy

• an endothermic change

• a physical change

Which one shows that a chemical reaction has occurred?

• dissolving

• melting

• formation of a gas

• bending

The following are the evidences that chemical reaction took place, EXCEPT:

• evolution of gas

• formation of precipitate

• formation of new element

• change in the intrinsic properties

Which of these is not a chemical reaction?

• Burning of wood
• Milk going bad
• Mixing vinegar and baking soda
• Melting of ice

The Law of Conservation of Mass says that matter can neither be __________ or __________.

• created; destroyed

• recycled; renewed

• subtracted; added

• joined; separated

In a reaction A + B ----> C,  reactant A has 5g and product  C has 9g. How many grams does reactant B should have? 

• 4g
• 5g
• 9g
• 14g

A precipitate is...

• a solid that falls out of a liquid solution
• a reactant in a reaction
• a clear substance
• the mass of a product

Exothermic reactions...

• Absorb energy
• Release energy
• Release Color
• Absorb Color