Question

please answer these questions, i am really sorry for troubling you :( i just need help with these:

1. Write word equation
a. Magnesium oxide dissolves in water , it forms Magnesium
Hydroxide
b. Zinc oxide reacts with Carbon to give Zinc and Carbon
monoxide
2. Write the chemical formula for rust. What are the two important
conditions necessary for Rusting?
3. Why freezing of water is considered as a physical change?
4. What are the changes observed when iron metal is placed in
copper sulphate solution?
5. Why it is advised that spoon should not be placed in pickle
jar?
6. Define the terms: a. endothermic and exothermic reactions.
b. Crystallisation
7. How is an element, compound and mixture different form each
other? Give examples for each.
8. Write the chemical formula (with steps) for the following -
a. Copper chloride
b. Zinc oxide
c. Magnesium Sulphide
d. Calcium Hydroxide
9. What the difference in 2X and X2.
10.What is the difference between the smallest particle of an element
and the smallest particle of a compound.
11.Write the symbols of: Calcium, Potassium, Silver, Magnesium,
Phosphate, Hydroxide, Gold and Aluminium.
12. What do you mean by water table in a water cycle?
13.List the reasons for depletion of water table.
14.Define: a) Infiltration b)ground water
15. If we keep on drawing water from underground, how will it
affect the water table?
16. Name the process by which ground water is discharged?

Answer 1

1.
1. Mgo +h2o gives mg(oh)2

2. zno + c gives zn +co

2. A. Iron + water gives iron oxide iron (in presence of oxygen)
Conditions necessary for rusting are metal water oxygen

3. Because there is a change in physical state.

4. When iron nail is placed in copper sulphate solution the following observation takes place :
1. Iron is more reactive and displays copper
2. The blue colour of cu turn green
3. Brown colour deposit is observed on the nail.

5. As metal reacts with acid to form salt and hydrogen gas which is very hazardous, it is adviced not to place a spoon in pickle

6. A . when heat is released along with the formation of products it is known as endothermic reaction.
B. When energy is absorbed it is known as exothermic.
C. Water of crystallization is the fixed amount of water molecules present in one formulae unit of salt.

11. Potassium-k , hydroxide -oh,
gold -au, aluminium al

15. If we keep on drawing water from underground it will ultimately lead to decrease in ground water and watertable

Answer 2

Answer:

1.

1. Mgo +h2o gives mg(oh)2

2. zno + c gives zn +co

2. A. Iron + water gives iron oxide iron (in presence of oxygen)

Conditions necessary for rusting are metal water oxygen

3. Because there is a change in physical state.

4. When iron nail is placed in copper sulphate solution the following observation takes place :

1. Iron is more reactive and displays copper

2. The blue colour of cu turn green

3. Brown colour deposit is observed on the nail.

5. As metal reacts with acid to form salt and hydrogen gas which is very hazardous, it is adviced not to place a spoon in pickle

6. A . when heat is released along with the formation of products it is known as endothermic reaction.

B. When energy is absorbed it is known as exothermic.

C. Water of crystallization is the fixed amount of water molecules present in one formulae unit of salt.

11. Potassium-k , hydroxide -oh,

gold -au, aluminium al

15. If we keep on drawing water from underground it will ultimately lead to decrease in ground water and watertable

Explanation: