Chemical reactions and Equations short 1

Question 1

What helps us to determine whether a chemical reaction has taken place ?

Answer 1

/ change in state
/ change in colour
/ evolution of a gas
/ change in temperature.

Question 2

What is a skeletal equation ?

Answer 2

If a equation is unbalanced then it is known as a skeletal equation

Question 3

What is Aqueous ?

Answer 3

The word aqueous (aq) is written if the reactant or product is present as a solution in water.

Question 4

What is Calcium oxide known as

Answer 4

Quick lime

Question 5

What is Calcium hydroxide known as

Answer 5

Slaked lime

Question 6

What is quick lime used for ?

Answer 6

It is used in the manufacturing of cement

Question 7

What are endothermic reactions ?

Answer 7

Reactions in which heat is absorbed are known as endothermic reactions.

Question 8

Which gases can be used for storing oil for a very long time.

Answer 8

Helium, as well as nitrogen, can be used for storage of a fresh sample of an oil for a long time

Question 9

Is decomposition of vegetable matter into compost a endothermic process ?

Answer 9

Yes

Question 10

Give a combination reaction exothermic in nature ?

Answer 10

C + O^2 → CO^2 + Heat