Endothermic and exothermic

Question 1

Endothermic reaction

Answer 1

Reactions transfer energy in

Question 2

exothermic

Answer 2

reactions transfer energy out

Question 3

Citric acid =20 o+ Sodium hydrogen carbonate powder. what happens to the temperature

Answer 3

The temperature goes down by 10oc

Question 4

Give and example of an exothermic reaction

Answer 4

Dilute sulphuric acid and sodium hydroxide this raises the temperature by 10 degrees

Question 5

Give an example of an endothermic reaction

Answer 5

Citric acid + sodium hydrogen powder does down by 10 oc

Question 6

Why can chemical reactions be useful

Answer 6

They can make products eg cement, polyester, medicines, burning coal

Question 7

Give an example of a negative chemical reactin

Answer 7

Rust

Question 8

How do you know that a chemical reaction has occurred .

Answer 8

Touch it smell it hear it see it

Question 9

What is a catalyst.?

Answer 9

It speeds up the reaction but is not changed in the process

Question 10

A change of state is when

Answer 10

Chocolate is melted

Question 11

Reactants are what.?

Answer 11

Elements

Question 12

products are what ?

Answer 12

Products

Question 13

magnesium and oxide

Answer 13

Magnesium oxide

Question 14

What is thermal decomposition..

Answer 14

Is where compounds breakdown into simpler compounds or elements

Question 15

What is a discrete vatiable

Answer 15

Eg copper carbonate not time