Class-8th Essential The Language of Chemistry Ch-5 ICSE Solutions

Class-8th Essential The Language of Chemistry Ch-5 ICSE Solutions Bharti Bhawan Chemistry Solutions Chapter-5. We Provide Step by Step Answer of Objective, True False , Match the following , Short / Long Answer Type of Exercise-5  The Language of Chemistry. Visit official Website CISCE for detail information about ICSE Board Class-8.

Class-8th Essential The Language of Chemistry Ch-5 ICSE Solutions of Bharti Bhawan Publishers

Board ICSE
Publications Bharti Bhawan
Subject Chemistry
Class 8th
Chapter-5 The Language of Chemistry
Book Name Essential
Topics Solution of Objective, True False , Fill in the blanks , Short / Long Answer Type Questions
Academic Session 2021-2022

ICSE Class-8th Essential Chemistry  Ch-5 The Language of Chemistry

Solutions of Bharti Bhawan Publishers Chemistry

Solutions of Objective, True False , Fill in the blanks , Short / Long Answer Type Questions


 Short-Answer Type Questions

(Solutions of Bharti Bhawan Publishers Chemistry ICSE Class-8th Essential Chemistry  Ch-5 The Language of Chemistry )

Page 54

Question 1: 

What does the symbol of an element mean ?

Answer :  An element symbol is a one- or two-letter abbreviation for a chemical element name. When a symbol consists of two letters, the first letter is always capitalized, while the second letter is lowercase. Element symbols also can refer to alchemy symbols for the elements or to the symbols used to describe isotopes.

Question 2: Are the symbols of carbon, chlorine, chromium and cobalt distinguished from each other ?

Answer : Yes

Question 3: 

Name three monoatomic gases with symbols ?

Answer :  

  • argon (Ar)
  • krypton (Kr)
  • xenon (Xe)

Question 4: 

From which words have been derived the symbols of sodium, potassium, iron and copper ?

Answer :  These names are derived from latin words as follows: Sodium – Natrium(Na). Potassium – Kalium(K). Iron – Ferrum(Fe).

Question 5: 

Derive the formulae of copper(II) chloride and copper(II) sulphate.

Answer : 

The chemical formula for Copper II chloride is CuCl2. Similarly, the molar mass of this salt is 134.45 g mol-1. When we look at the dehydrated form of this salt, it has a molecular mass of 170.48 g mol-1. Moreover, the structure of this anhydrous salt consists of 1 cation Cu2+ and 2 anion Cl.

The structure of Copper (II) chloride is a distorted octahedron with a copper cation bound to 6 chloride anions. Thus, in this dehydrated form, it forms by a Cu2+ centred atom, which is bounded by 2 water molecules and 2 chlorine anions Cl.

Question 6: 

Name the compounds FeO and Fe2O3

Answer :  FeO is called ferrous oxide while Fe2O3 is ferric oxide

Question 7: 

What is the formula of aluminum sulphate?

Answer :  Iron(III) oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron(II) oxide (FeO) the rarer form, and iron(II,III) oxide (Fe3O4) which naturally as magnetite.

Question 8: 

What do you mean by a balanced chemical equation ?

Answer :  A balanced chemical is equation has equal numbers of atoms for each element involved in the reaction are represented on the reactant and product sides. This is a requirement the equation must satisfy to be consistent with the law of conservation of matter.

Question 9: 

How any molecules of hydrogen chloride will be formed when a molecule of hydrogen reacts with one of chlorine?

Answer :   From the balanced equation H2 + Cl2= 2HCl, one mole of hydrogen will react with one mole of chlorine, so hydrogen is in excess. There are two moles HCl formed for each mole of Cl2, hence 2 x 0.141 = 0.282 moles HCl is produced.

Question 10: 

How many molecules of hydrogen will be required by one of oxygen for conversion into water ?

Answer :  When hydrogen react with oxygen, two molecules of hydrogen and one molecule of oxygen are consumed for every two molecules of water proceeded. Thus one molecule of hydrogen will be required by one of oxygen for conversion into water.

Question 11: 

If a molecule of nitrogen combines with three of hydrogen, how many molecules of ammonia will be formed ?

Answer :  We see that 1 molecule of nitrogen reacts with 3 molecules of hydrogen to form 2 molecules of ammonia. This is the smallest possible relative amounts of the reactants and products. To consider larger relative amounts, each coefficient can be multiplied by the same number.

Question 12: 

Carbon dioxide tums limewater milky. Write a chemical equation for the reaction, conveying as much information as possible.

Answer :  Resultant carbon dioxide passed through limewater in the right tube, producing a milky solution due to precipitation of the insoluble suspension of calcium carbonate: Ca(OH)2(aq) + CO2(g) → CaCO3(s) + H2O


 Long-Answer Type Questions

(Solutions of Bharti Bhawan Publishers Chemistry ICSE Class-8th Essential Chemistry  Ch-5 The Language of Chemistry )

Page 54

Question 1: 

Discuss the trend in valency of the elements that one observes when they are arranged in the increase Order of atomic number. Knowing the valency’s of the constituent elements, how can one arrive at the formula of a binary compound? Give three examples.

Answer :  valency is the measure of the combining capacity of atoms or molecules. therefore it is the capacity of an atom of a single element to react and combine with particular numbers of atoms of another element.

Question 2: 

Show with examples how we take care of the electrical charges on radicals while finding out the formula of a compound made up of them.

Answer :  Determine the electrons in the outer shells of the elements in the radical. This can be determined by counting how many columns on the periodic table the element is from a noble gas. For example, the cyanide radical (CN) has four outer electrons for carbon and five outer electrons for nitrogen.

Combine the atoms with covalent bonds, so they share as many electrons as possible without exceeding eight electrons. For cyanide, both carbon and nitrogen can share three electrons each. When nitrogen adds these three electrons to its existing five, it has eight electrons, known as an octet. Carbon ends up with seven electrons

Question 3  

Discuss how you can make a balanced chemical equation convey more than the symbols and  formulae of the reactants and the products.

Answer : 

.The actual result of chemical change.

2. The substances take part in a chemical reaction and substances formed as a result of reaction.

3. The number of atoms of each element participating in the reaction.

4.The number of molecules of different substances taking part in the chemical reaction.

For example:

Zn + H2SO4  →  ZnSO4  + H2

Here one molecule of zinc, one molecule of sulphur acid react to give one molecule of zinc sulphate and one molecule of Hydrogen.

5. Composition of respective molecules i.e. one molecule of sulphur acid contains two atoms of hydrogen, one atom of sulphur and four atoms of oxygen.

6. Relative moleculer masses of different substances i.e. molecular mass of


 Objective Type Questions

(Solutions of Bharti Bhawan Publishers Chemistry ICSE Class-8th Essential Chemistry  Ch-5 The Language of Chemistry )

Page 55

Choose the correct option.

Question 1: Which of the following symbols is not derived from the Latin name of the element ?

(a) Fe

(b) Cu

(c) Cr

(d) Pb

Answer (c) Cr

Question 2:  Which of the following symbols is derived from the Latin name of the element

(a) Ag

(b) He

(c) Ne

(d) Mg

Answer (a) Ag

Question 3: Which element among the ones appearing below is pentavalent

(a) NH3

(b) PCl5

(c) CaO

(d) MgSO4

Answer (b) PCl5

Question 4: What is the valency of Mg in Mg3NH2 ?

(a) 2

(b) 3

(c) 4

(d) 1

Answer (d) 1

Question 5:  What is the value of X in the following equation?

CaCO3(s) + x HCl(aq) —> CaCl2(aq) + H2O(I) + CO2(g)

(a) 3

(b) 4

(c)1

(d) 2

Ans (d) 2

Hint:-  CaCO3 + 2 HCl → CaCl2 + H2O + CO2

Question 6: Which of the following is not a balanced chemical equation?

(a) CaCO3 —–>  CaO + CO2

(b) 2KCIO3 —– > KCI + 3O2

(c) SO2 + H2O – H2SO3

(d) CO2 + HO2 —-> H2CO3

Ans (b) 2KCIO3 —– > KCI + 3O2

Hint :- K is not balance

Fill in the Blanks 

1. Nitrogen is ……trivalent……… in AlN. (monovalent/trivalent)

2. One sulphate radical will take up …….two……. sodium radical(s) to form sodium sulphate (one/two)

3. ……………… H2O2  +  (MnO2)  ——> …………… . H2O + O2

Hint:-        2H2O2 +  MnO2 → 2 H2O + O2

4. Na2CO3 + HCI —> …….  NaCl +H2O + CO2

5. ………… NaHCO3  ——–> (Heat) Na2CO3 +  H2O

Write T for true and ‘F for false for the following statements.

1. Ozone is a triatomic gas. T

2 The atomicity of sulphur is 4   F

3. One dipositive radical will require only one delegative radical to form a compound. F

4. A noble-gas element is monoatomic as well as monovalent. T

5. A substance in solution is indicated in a chemical equation by the symbol (s). T

-: End of Class-8th Essential The Language of Chemistry Ch-5 ICSE  Bharti Bhawan Publishers :-


Return To :-   ICSE Class-8 Essential Chemistry Solution Bharti Bhawan Publishers

Thanks

Please Share with your ICSE friends if it is helpful

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.