Language of Chemistry ICSE Class-9 Concise Selina Solutions
Chapter-1 Language of Chemistry
Language of Chemistry ICSE Class-9 Concise Selina Solutions Chapter-1 . Therefore we Provide Step by Step Solutions of Exercise-1(A), Exercise-1(B) and Exercise-1(C) Exercise-1 Language of Chemistry. Visit official Website CISCE for detail information about ICSE Board Class-9.
Language of Chemistry ICSE Class-9 Concise Selina Solutions Chapter-1
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Note :- Before Viewing Selina Concise Solutions of Language of Chemistry Chapter-1 . Read the whole chapter carefully with Chemical Formula. Focus on Symbol, Molecular Formulas Atomic Mass and Balancing Chemical Equations. Also read Radicals and Naming Compound.
Exercise-1(A), Chapter-1 Language of Chemistry Selina Concise Solutions
What is a symbol? What information does it convey?
A symbol is the short form which stands for the atom of a specific element or the abbreviations used for the names of elements
It represents a specific element.
(i)It represents one atom of an element.
(ii)A symbol represents how many atoms are present in its one gram (gm) atom.
(iii) It represents the number of times an atom is heavier than one atomic mass unit (amu) taken as a standard.
Why is the symbol S for Sulphur, but Na for sodium and Si for silicon?
In most cases, the first letter of the name of the element is taken as the symbol for that element and written in capitals (e.g. for Sulphur, we use the symbol S). In cases where the first letter has already been adopted, we use a symbol derived from the Latin name (e.g. for sodium/Atrium, we use the symbol Na). In some cases, we use the initial letter in capital together with a small letter from its name (e.g. for silicon, we use the symbol Si).
Write the full form of IUPAC.
Name the elements represented by the following symbols:
Au, Pb, Sn, Hg
The full form of IUPAC is International Union of Pure and Applied Chemistry.
Names of the elements:
Au – Gold
Pb – Lead
Sn – Tin
Hg – Mercury
If the symbol for Cobalt, Co, were written as CO, what would be wrong with it?
Co stands for Cobalt. If we write CO, then it would mean that it is a compound containing two non-metal ions, i.e. carbon and oxygen, which forms carbon monoxide gas.
What do the following symbols stand for?
(a) H (b) H2 (c) 2H (d) 2H2
(a) One Hydrogen atom
(b) Hydrogen molecules
(c) Two Atom of hydrogen
(d) Two molecules of hydrogen.
What is meant by atomicity?
Name the diatomic element.f
The number of atoms of an element that join together to form a molecule of that element is known as its automatically.
Diatomic molecules: H2, O2, N2, Cl2
(a) Explain the terms ‘valence’ and ‘variable valency
(b) How are the elements with variable valence named? Explain with an example
Valence of Na is +1 because it can lose one electron.
Valence of O is -2 because it can accept two electrons.
Variable valence: It is the combining capacity of an element in which the metal loses more electrons from a shell next to a valence shell in addition to electrons of the valence shell.
If an element exhibits two different positive valences, then
. for the lower valence, use the suffix -OUS at the end of the name of the metal
for the higher valency, use the suffix -IC at the end of the name of the metal.
|Ferrous (Fe2+)||Ferric (Fe3+)|
Give the formula and valence of:
(a) Acuminate ……
(b) Chromate ………
(c) Aluminum ……
(d) Cupric ……
(a) What are chemical formulas?
(b) What is the significance of formula? Give an example to illustrated.
(a) a set of chemical symbols showing the elements present in a compound and their relative properties.
(b) Significance of the molecular formula:
It represents both molecule and molecular mass of the compound.
represents the respective number of different atoms present in one molecule of the compound.
and Also It represents the ratios of the respective masses of the elements present in the compound.
What do you understand by the following terms?
(a) Acid radical (b) Basic radical
(a) Acid radical:
The electronegative or negatively charged radical is called an acid radical.
(b) Basic radical:
The electropositive or positively charged radical is called a basic radical.
Select the basic and acidic radicals in the following compounds.
(e)Mg (OH) 2
|Acidic radical||Basic radical|
Write chemical formula of the sulphate of Aluminum, Ammonium and Zinc.
Valences of aluminum, ammonium and zinc are 3, 1 and 2, respectively.
The valences of sulphate is 2.
Hence, chemical formulae of the sulphates of aluminum, ammonium and zinc are Al2(SO4)3, (NH4)2SO4 and ZnSO4.
The valence of an element Ais 3 and that of element Bis 2. Write the formula of the compound formed by the combination of Aand B.
Formula of the compound = A2B3
Match the following:
|(a) Boric acid||xvi. H3BO3|
|(b) Phosphoric acid||xvii. H3PO4|
|(c) Nitrous acid||xv. HNO2|
|(d) Nitric acid||xiv. HNO3|
|(e) Sulphurous acid||xiii. H2SO3|
|(f) Sulphuric acid||xviii. H2SO4|
|(g) Hydrochloric acid||xii. HCl|
|(h) Silica (sand)||ii. SiO2|
|(i) Caustic soda
|(j) Caustic potash (potassium hydroxide)||iv. KOH|
| (k) Washing soda
| (l) Baking soda
| (m) Lime stone
|(n) Water||viii. H2O|
|(o) Hydrogen sulphide||vii. H2S|
|(p) Ammonia||xi. NH3|
|(q) Phosphine||ix. PH3|
|(r) Methane||x. CH4|
Write the basic radicals and acidic radicals of the following and then write the chemical formulae of these compounds.
(n)Potassium Ferro cyanide
Write the chemical names of the following compounds:
(a) Ca3 (PO4)2
(d) Mn3 (BO3)2
(e) Mg (HCO3)2
(f) Na4Fe (CN)6
(g) Ba (ClO3)2
(i) (CH3COO) 2Pb
Chemical names of compounds:
Ca3(PO4)2– Calcium phosphate
K2CO3– Potassium carbonate
K2MnO4 – Potassium manganite
Mn3(BO3)2– Manganese (II) borate
Mg(HCO3)2– Magnesium hydrogen carbonate
Na4Fe(CN)6– Sodium Ferro cyanide
Ba(ClO3)2– Barium chlorate
Ag2SO3– Silver sulphite
(CH3COO)2Pb – Lead acetate
Na2SiO3– Sodium silicate
Give the names of the following compounds.
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
(iii) . Al2O3
(c) The valence of nitrogen in nitrogen dioxide (NO2) is
(a)iii. The formula of a compound represents a molecule.
(b)iii. The correct formula of aluminum oxide is Al2O3.
(c)iv. The valence of nitrogen in nitrogen dioxide (NO2) is four.
Give the names of the elements and number of atoms of those elements present in the following compounds.Sodium sulphateQuick limeBaking soda (NaHCO3)AmmoniaAmmonium dichromate
Sodium sulphate – Na2SO4There are two sodium atoms, one Sulphur atom and four oxygen atoms.Quick lime – CaOThere is one calcium atom and one oxygen atom.Baking soda – NaHCO3There is one sodium, carbon and hydrogen atom and three oxygen atoms.Ammonia – NH3There is one nitrogen atom and three hydrogen atoms.Ammonium dichromate – (NH4) Cr2O7There two ammonium atoms, two chromium atoms and seven oxygen atoms.
The formula of the sulphate of an element M is M2 (SO4)3Write the formula of its Chloride Oxide Phosphate Acetate
The valence of metal M is 3. So, the formulae are as follows:Chloride – MCl3Oxide – M2O3Phosphate – M(PO4)Acetate – M(CH3COO)3
EXERCISE -1(B) Selina Concise Solutions Chapter-1 Language of Chemistry
What is a chemical equation? Why it is necessary to balance it?
A chemical equation is the symbolic representation of a chemical reaction using the symbols and formulae of the substances involved in the reaction.
A chemical equation needs to be balanced because a chemical reaction is just a rearrangement of atoms.
Atoms themselves are neither created nor destroyed during the course of a chemical reaction.
The chemical equation needs to be balanced to follow the law of conservation of mass.
State the information conveyed by the following equation:
Zn(s) + 2HCl (aq) → ZnCl2 (aq) + H2 ↑
A solid metal zinc reacts with hydrochloric acid in the aqueous state to produce zinc chloride in the aqueous state and hydrogen gas.
What is the limitation of the reaction given in question 2?
The chemical equation given in question 2 does not give the time taken for the completion of the reaction.
Also, it does not give information about whether heat is absorbed or evolved during the reaction.
Write the chemical equations for the following word equations and balance them.
(a)Carbon + Oxygen → Carbon dioxide
(b)Nitrogen + Oxygen → Nitrogen monoxide
(c) Calcium + Nitrogen → Calcium nitride
(d)Calcium oxide + Carbon dioxide → Calcium carbonate
(e)Magnesium+ Sulphuric acid → Magnesium sulphate + Hydrogen
(f) Sodium reacts with water to form sodium hydroxide and hydrogen
(a)C + O2→ CO2
(b )N2 + O2→ 2NO
(c) 3Ca + N2→ Ca3N2
(d)CaO + CO2→ CaCO3
(e)Mg + H2SO4→ MgSO4 + H2↑
(f)Na + H2O → NaOH + H2↑
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 + SO2
(h). S + H2SO4 → SO2 + H2O
(i.) S + HNO3 → H2SO4 + NO2 + H2O
(j). MnO2 + HCl → MnCl2 + H2O + Cl2
(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 (NO3)2 + H2O + NO2
Balanced chemical equations:
(a) 3Fe + 4H2O → Fe3O4 + 4H2
(b) 3Ca + N2 → Ca3N2
(c) Zn + 2KOH → K2ZnO2 + H2
(d)Fe2O3 + 3CO → 2Fe + 3CO2
(e) 3PbO + 2NH3 → 3Pb + 3H2O + N2
(f) 2Pb3O4 → 6PbO + O2
(g) 2PbS + 3O2 → 2PbO + 2SO2
(h)S + 2H2SO4 → 3SO2 + 2H2O
(i)S + 6HNO3 → H2SO4 + 6NO2 + 2H2O
(j) MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
(k) C + 2H2SO4 → CO2 + H2O + SO2
(l) 2KOH + Cl2 → KCl + KClO + H2O
(m) 2NO2 + H2O → HNO2 + HNO3
(n) Pb3O4 + 8HCl → 3PbCl2 + 4H2O + Cl2
(O) 2H2O + 2Cl2 → 4HCl + O2
(p) 2NaHCO3 → Na2CO3 + H2O + CO2
(Q) 2HNO3 + H2S → 2NO2 + 2H2O + S
(r) P + 5HNO3 → 5NO2 + H2O + H3PO4
(s) Zn + 4HNO3 → Zn (NO3)2 + 2H2O + 2NO2
EXERCISE 1 (C), Selina Concise Solutions Chapter-1 Language of Chemistry
Fill in the blanks:
(a) Dalton used symbol _____ for oxygen _____ for hydrogen.
(b)Symbol represents _____ atom(s) of an element.
(c)Symbolic expression for a molecule is called _____. .
(d)Sodium chloride has two radicals. Sodium is a _____ radical while chloride is _____ radical.
(e)Valence of carbon in CH4 is _____, in C2H6 _____, in C2H4 ___ and in C2H2 is ____.
(f)Valence of Iron in FeCl2 is _____ and in FeCl3 it is ____.
(g)Formula of iron (ill) carbonate is _____.
(a) Dalton used symbol [O] for oxygen,[H] for hydrogen.
(b) Symbol represents gram atom(s) of an element.
(c) Symbolic expression for a molecule is called molecular formula.
(d) Sodium chloride has two radicals. Sodium is a basic radical, while chloride is an acid radical.
(e) Valence of carbon in CH4 is 4, in C2H64, in C2H44 and in C2H2 is 4.
(f) Valence of iron in FeCl2 is 2 and in FeCl3 it is 3.
(g) Formula of iron (III) carbonate is Fe2 [CO3]3.
Complete the following table.
(c)Find the weights of reactants and products.
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.
(d) State the law which this equation satisfies.
(a) NaCl + AgNO3→ NaNO3 + AgCl↓
(b) It is a balanced equation.
(c) Weights of reactants: NaCl – 58.44, AgNO3– 169.87
Weights of products: NaNO3 – 84.99, AgCl – 143.32
NaCl + AgNO3 → NaNO3 + AgCl
(23+35.5) + (108+14+48) → (23+14+48) + (108+35.5)
58.5 + 170 → 85 + 143.5
228.5 g → 228.5 g
(d). Law of conservation of mass: Matter is neither created nor destroyed in the course of a chemical reaction.
What information does the following chemical equation convey?
(a) Zn + H2SO4 → ZnSO4+ H2
The actual result of a chemical change.
Substances take part in a reaction, and substances are formed as a result of the reaction.
(i)Here, one molecule of zinc and one molecule of sulphuric acid react to give one molecule of zinc sulphate and one molecule of hydrogen.
(ii) Composition of respective molecules, i.e. one molecule of sulphuric acid contains two atoms of hydrogen, one atom of sulphur and four atoms of oxygen.
(iii) Relative molecular masses of different substances, i.e. molecular mass of
Zn = 65
H2SO4 = (2+32+64) = 98
ZnSO4 = (65+32+64) = 161
H2 = 2
(iv) 22.4 liters of hydrogen are formed at STP.
Mg + 2HCl → MgCl2+ H2
This equation conveys the following information:
(i)Magnesium reacts with hydrochloric acid to form magnesium chloride and hydrogen gas.
(ii) 24 g of magnesium reacts with 2(1 + 35.5) = 73 g of hydrochloric acid to produce (24 + 71), i.e. 95 g of magnesium chloride.
(iii)Hydrogen produced at STP is 22.4 liters.
(a)What are polyatomic ions? Give two examples.
(b) Name the fundamental law that is involved in. every equation
(a) A polyatomic ion is a charged ion composed of two or more covalently bounded atoms.
(b) Fundamental laws which are involved in every equation:
(i) A chemical equation consists of formulae of reactants connected by a plus sign (+) and arrow (→) followed by the formulae of products connected by the plus sign (+).
The sign of an arrow (→) is to read ‘to form’. It also shows the direction in which the reaction is predominant.
The fundamental law followed by every equation is ‘Law of Conservation of Mass’.
What is the valence of?
(a)Fluorine in CaF2
(b) Sulphur in SF6
(c) Phosphorus in PH3
(d) Carbon in C4
(e) Nitrogen in the following compounds:
(i) N2O5 (ii) N2O3(iii) NO2 (iv) NO
(f) Manganese in MnO2
(g) Copper is Cu2O
(h) Magnesium in Mg3
(a) Fluorine in CaF2 is -1.
(b) Sulphur in SF6 is -6.
(c) Phosphorus in PH3 is +3.
(d) Carbon in CH4 is +4.
(e) Valence of nitrogen in the given compounds:
(i) N2O3 = N is +3
(ii) N2O5 = N is +5
(iii) NO2 = N is +4
(iv) NO = N is +2
Why should an equation be balanced? Explain with the help of a simple equation.
According to the law of conservation of mass, ‘matter can neither be created nor can it be destroyed’. This is possible only if the total number of atoms on the reactants side is equal to the total number of atoms on the products side. Thus, a chemical reaction should always be balanced.
e.g. KNO3 → KNO2 + O2
In this equation, the number of atoms on both sides is not the same, and the equation is not balanced.
The balanced form of this equation is
2KNO3 → 2KNO2 + O2
Write the balanced chemical equations of the following word equation.
(a) Sodium hydroxide + sulphuric acid → sodium sulphate + water
(b)potassium bicarbonate + sulphuric acid → potassium sulphate + carbon dioxide + water
(c) iron + sulphuric acid → ferrous sulphate + hydrogen.
(d) chlorine + sulphur dioxide + water → sulphuric acid + hydrogen chloride
(e) silver nitrate → silver + nitrogen dioxide + oxygen
(f) copper + nitric acid → copper nitrate + nitric oxide + water
(g) ammonia + oxygen → nitric oxide + water
(h) barium chloride + sulphuric acid → barium sulphate + hydrochloric acid
(i) zinc sulphide + oxygen → zinc oxide + sulphur dioxide
(j) aluminium carbide + water → aluminium hydroxide + methane
(k) iron pyrites(FeS2) + oxygen → ferric oxide + sulphur dioxide
(l) potassium permanganate + hydrochloric acid → potassium chloride + manganese chloride + chlorine + water
(m) aluminium sulphate + sodium hydroxide → sodium sulphate + sodium meta aluminate + water.
(n) aluminium + sodium hydroxide + water → sodium meta aluminate + hydrogen
(o) potassium dichromate + sulphuric acid → potassium sulphate + chromium sulphate + water + oxygen.
(p) potassium dichromate + hydrochloric acid → Potassium chloride + chromium chloride + water + chlorine
(q)sulphur + nitric acid → sulphuric acid + nitrogen dioxide + water.
(r) sodium chloride + manganese dioxide + sulphuric acid → sodium hydrogen sulphate + manganese sulphate + water + chlorine.
(a)2NaOH + H2SO4 → Na2SO4 + 2H2O
(b)2KHCO3 + H2SO4 → K2SO4 + 2CO2 + 2H2O
(c)Fe + H2SO4 → FeSO4 + H2
(d) Cl2 + SO2 + 2H2O → H2SO4 + 2HCl
(e) 2AgNO3 → 2Ag + 2NO2 + O2
(f) 3Cu + 8HNO3 → 3Cu(NO3)2 + 2NO + 4H2O
(h) BaCl2 + H2SO4 → BaSO4 + 2HCl
(i) 2ZnS + 3O2 → 2ZnO + 2SO2
(j) Al4C3 + 12H2O → 4Al(OH)3 + 3CH4
(k) 4FeS2 + 11O2 → 2Fe2O3 + 8SO2
(l) 2KMnO4 + HCl → 2KCl + 2MnCl2 + 5Cl2 + 8H2O
(m) Al2(SO4)3 + 8NaOH → 3Na2SO4 + 2NaAlO2 + 4H2O
(n) 2Al + 2NaOH + 2H2O → 2NaAlO2 + 3H2
(o) 2K2Cr2O7 + 8H2SO4 → 2K2SO4 + 2Cr2(SO4)3 + 8H2O + 3O2
(p) K2Cr2O7 + 14HCl → 2KCl + 2CrCl3 + 7H2O + 3Cl2.
(q) S + HNO3 → H2SO4 + NO2 + H2O
(r) 2NaCl + MnO2 + 3H2SO4 → 2NaHSO4 + MnSO4 + 2H2O + Cl2
(a)Define atomic mass unit.
(b) Calculate the molecular mass of the following:
(iii) (NH2)2CO (IV) Mg3N2
Given atomic mass of Na = 23, H = 1, O = 16, C = 12, N = 14, Mg = 24, S = 32.
(a)Atomic mass unit (amu) is equal to one-twelfth the mass of an atom of carbon-12 (atomic mass of carbon taken as 12).
Choose the correct answer from the options given below.
Modern atomic symbols are based on the method proposed by
The number of carbon atoms in a hydrogen carbonate radical is
The formula of iron (III) sulphate is
(ii) Fe (SO4)3
(iii). Fe2 (SO4)3
In water, the hydrogen-to-oxygen mass ratio is
(I) 1: 8
(Ii) 1: 16
(Ii) 1: 32
(IV) 1: 64
The formula of sodium carbonate is Na2CO3 and that of calcium hydrogen carbonate is
(ii) Ca (HCO3)2
(iv). Ca (HCO3)3
(a) Iii. Berzelius
(c) Iii. Fe2 (SO4)3
(d) i. 1:8
(e) Ii. Ca (HCO3)2
Correct the following Statement
(a)A molecular formula represent an elements.
(b) Molecular formula of water is H2O2.
(c) A molecule of Sulphur is monoatomic.
(d) CO and Co both represent cobalt.
(e) Formula of iron (III) oxide is FeO.
Calculate the relative molecular masses of:
(f) potassium chlorate
(g) Ammonium chloroplatinate =(NH4)2 SO4
[At. Mass: C = 12, H =1, O = 16, Cl = 35.5, N = 14, Cu = 63.5, S =32, Na = 23, K = 39, Pt = 195, Ca = 40, P =31 Mg = 24,]