Selina solutions concise chemistry class 9 icse Solutions for Chapter 1 chapter 1 the language of chemistry

What is a symbol? What information does it convey?

The fundamental unit is:

(a) newton

(b) pascal

(c) hertz

(d) second

Why is the symbol S for Sulphur, but Na for Sodium and Si for Silicon?

Write the full form of IUPAC. Name the elements represented by the following Symbols: Au, Pb, Sn, Hg

If the symbol for cobalt, Co were written as CO, What would be wrong with it?

What do the following symbols stand for?

a) H

b) H2

c) 2H

d) 2H2

What is meant by atomicity? Name a diatomic element.

a) Explain the terms valency and variable valency

b) How are the elements with variable valency named? Explain with an example

Give the formula and valency of

a) aluminate

b) chromate

c) aluminium

d) cupric

a) What is a chemical formula?

b) What is the significance of a formula? Give an illustrate

Select the basic radical in the following compounds

a) \mathrm{MgSO} 4 b) \left(\mathrm{NH}_{4}\right)_{2} \mathbf{c}) \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3} d) \mathrm{ZnCO}_{3} e) \mathbf{M g}(\mathbf{O H})_{2}

The valency of element A is 3 and that of element B is 2. Write the formula of the compound formed by the combination of A and B.

Complete the following statements by selecting the correct option.

a) The formula of a compound represents i) an atom

ii) a particle

iii) a molecule

iv) a combination

b) The correct formula of aluminum oxide is

i) AlO3

ii) AlO2

iii) Al2O3

iv) Al3O2

c) The valency of Nitrogen in Nitrogen dioxide( NO2) is

i) One

ii) Two

iii) Three

iv) Four

The formula of the sulphate of an element M is M2(SO4)3. Write the formula for it.

a) Chloride

b) Oxide

c)Phosphate

d) Acetate

State the information conveyed by the following equation.

Zn(s) + 2HCl(aq) ZnCl2(aq) + H2

Write the limitation of reaction given in question 2

Balance the following equations

a) Fe+ H2O -Fe3O4+ H2

b) Ca+ N2 -Ca3N2

c) Zn+ KOH -K2ZnO2 + H2

d) Fe2O3 + CO Fe + CO2

e) PbO + NH3 -Pb+ H2O +N2

f) Pb3O4- PbO + O2

g) PbS+ O2 -PbO + O2

h) S + H2SO4 -SO2+ H2O

i) S + HNO3 -H2SO4 + NO2 + H2O

j) MnO2 + HCl -MnCl2 + H2O + SO2

k) C + H2SO4 CO2 + H2O + SO2

l) KOH + Cl2- KCl + KClO + H2O

m) NO2 + H2O -HNO2 + HNO3

n) Pb3O4 + HCl -PbCl2 + H2O + Cl2

o) H2O + Cl2 -HCl + O2

p) NaHCO3- Na2CO3 + H2O+ CO2

q) HNO3+ H2S NO2 + H2O +S

r) P + HNO3- NO2+H2O+H3PO4

s) Zn+ HNO3- Zn(NO)3+ H2O + NO2

A microscope is provided with a main scale graduated with 20 divisions in 1cm and a vernier scale with 50 divisions on it of length same as of 49 divisions of main scale. Find the least count of the microscope.

Sodium chloride reacts with silver nitrate to produce silver chloride and sodium nitrate

a) Write the equation

b) Check whether it is balanced, if not balance it.

c) Find the weights of reactants and products.

d) State the law that this equation satisfies?

What information does the following chemical equations convey?

a) Zn+H2SO4— ZnSO4 + H2

b) Mg+ 2Hcl –MgCl2 + H2

a) What are poly-atomic ions? Give two examples

b) Name the fundamental law involved in every equation

What is the valency of?

a) Fluorine in CaF2

b) Sulphur in SF6

c) Phosphorous in PH3

d) Carbon in CH4

e) Nitrogen in the following compound

i) N2O3 ii) N2O5 iii) NO2 iv) NO

f) Manganese in MnO2

g) Copper in Cu2O

h) Magnesium in Mg3N2

Why should an equation be balanced? Explain with the help of a simple equation.

Write the balanced chemical equations of the following word equations

Choose the correct answer from the options given below

a) Modern atomic symbols are based on the methods proposed by

i) Bohr ii) Dalton iii) Berzelius d) Alchemist

(b)The number of carbon atoms in a hydrogen carbonate radical is

(i)one

(ii)two

(ii)three

(iv)four

(c)The formula of iron

(III)sulphate is

(i)Fe3SO4

(ii)Fe(SO.)3

(iii)Fe(SO4)3

(iv)FeSO4

(d)In water, the hydrogen-to-oxygen mass ratio is

(i)1:8

(ii)1:16

(iii)1:32

(iv)1:64

(e)The formula of sodium carbonate is Na, CO,and that of calcium hydrogen carbonate is

(i)CaHCO3

(ii)Ca(HCO3)2

(iii)Ca,HCO3

(iv)Ca(HCO)3

Calculate the relative molecular masses of:

(a)CHCI3

(b)(NH4)2Cr2O7

(c)CuSO4.5H2O

(d)(NH4)2SO4

(e)CH3COONa

(f)Potassium chlorate

(g)Ammonium chloroplatinate(NH4)2PLCl6

[At.mass:C=12,H=1,0=16,Cl=35.5,N=14,Cu=63-5,S=32,Na=23,K=39,Pt=195,Ca=40,P=31,Mg=24]

13.Give the empirical formula of:

(a)Benzene(C6H6) (b)Glucose(C6H1206)

(c)Acetylene(C2H2) (d)Acetic acid(CH3COOH)

Calculate the percentage composition of each element in Potassium chlorate, KCIO.

Urea is a very important nitrogenous fertilizer. Its formula is CON, H4. Calculate the percentage of

carbon in urea. (C=12,0=16,N=14 and H=1)