EASE preparation 8th grade

The picture shows the cellular respirotary sistem.

From the reaction, respirotary is an example of

• Chemical change

• Physical change

• Biological change

• transformatial change

In chemical reactions, the Law of Conservation of Mass will show

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

• The total mass of reactants is greater than the total mass of products.

• The total mass of reactants is same with the total mass of products.

• The total mass of reactants is cannot be compared with the total mass of products.

In the reaction of carbon dioxide formation,

From this reaction, carbon dioxide is called as a

• reactant

• product

• catalyst

• none of the above

Dika is cooking boiled egg

Which best describes what has occured ?

• A physical change, because the matter changed its state.

• A physical change, because new substances was formed

• A chemical change, because the matter changed its state

• A chemical change, because new substances was formed

.......... gas is required for burning

Calcium react with hydrochloric acid. What would be the word equation of this reaction?

• Calsium + hydrochloric acid ---> Calsium sulfate + hydrogen

• Calsium + sulfuric acid acid ---> Calsium chloride + hydrogen

• Calsium + hydrochloric acid ---> Calsium chloride + hydrogen

• Calsium + sulfuric acid ---> Calsium sulfate + hydrogen

Sodium carbonate + hydrochloric acid → .............. + carbon dioxide + water

.............. + hydrochloric acid → magnesium chloride + carbon dioxide + water

magnesium carbonate + ................... → magnesium sulfate + carbon dioxide + water

an experiment is conducted where magnesium metal is added to sulfuric acid.

1. the name of the gas given off in this reaction is hydrogen

2. the product of this reaction is magnesium sulfate and hydrogen gas

3. the word equation is: magnesium + sulfuric acid ---> magnesium sulfate + hydrogen

4. the name of the salt in this reaction is magnesium chloride

Which of the statements are correct for the reaction?

• 1, 2 and 3

• 1 and 2

• 2 and 3

• 1 only