Viraf J. Dalal solutions for Simplified ICSE Chemistry [English] Class 9 chapter 1 - The Language Of Chemistry [Latest edition]

An element X is trivalent. Write the balanced equation for the combustion of X in oxygen.

The formula of the nitride of a metal X is XN, state the formula of :

1. its sulphate
2. its hydroxide.

What is the valency of nitrogen in :

1. NO
2. N₂O
3. NO₂

XCl₂ is the chloride of a metal X. State the formula of the sulphate and the hydroxide of the metal X.

What is meant by the term ‘symbol’?

Give the qualitative and quantitative meaning of the term ‘symbol’.

Name three metals whose symbols are derived from the first letter of the name of the element.

Name three metals whose symbols are derived: from their Latin names.

Explain the meaning of the term ‘valency’.

State why the valency of the metal potassium is +1 and of the non-metal chlorine is -1.

What is meant by the term ‘variable valency’. Give a reason why silver exhibits a valency of +1 and +2.

Give examples of eight metals that show variable valency.

State the valency of sulphur in :

(a) SO₂
(b) SO₃

State the name of the element or radical given below

K

State the valency of the element or radical given below

K

State the name of the element or radical given below

Cr₂O₇

State the valency of the element or radical given below

Cr₂O₇

State the name of the element or radical given below.

Cl

State the name of the element or radical given below

Cl

State the valency of the element or radical given below

Cl

State the name of the element or radical given below

Ni

State the valency of the element or radical given below

Ni

State the name of the element or radical given below

ClO₃

State the valency of the element or radical given below

ClO₃

State the name of the element or radical given below

CO₃

State the valency of the element or radical given below

CO₃

State the name of the element or radical given below

Ba

State the valency of the element or radical given below

Ba

State the name of the element or radical given below

HCO₃

State the valency of the element or radical given below

HCO₃

State the name of the element or radical given below

NO₂

State the valency of the element or radical given below

NO₂

State the name of the element or radical given below

Na

State the valency of the element or radical given below

Na

State the name of the element or radical given below

Br

State the valency of the element or radical given below

Br

State the name of the element or radical given below

Zn

State the valency of the element or radical given below

Zn

State the name of the element or radical given below

Mg

State the valency of the element or radical given below

Mg

State the name of the element or radical given below

O

State the valency of the element or radical given below

O

State the name of the element or radical given below

Co

State the valency of the element or radical given below

Co

State the name of the element or radical given below

CrO₄

State the valency of the element or radical given below

CrO₄

State the name of the element or radical given below

ClO

State the valency of the element or radical given below

ClO

State the name of the element or radical given below

MnO₄

State the valency of the element or radical given below

MnO₄

State the name of the element or radical given below

Li

State the valency of the element or radical given below

Li

State the name of the element or radical given below

I

State the valency of the element or radical given below

I

State the name of the element or radical given below

OH

State the valency of the element or radical given below

OH

State the name of the element or radical given below

O₂

State the valency of the element or radical given below

O₂

State the name of the element or radical given below

ZnO₂

State the valency of the element or radical given below

ZnO₂

State the name of the element or radical given below

SiO₃

State the valency of the element or radical given below

SiO₃

State the name of the element or radical given below

NO₃

State the valency of the element or radical given below

NO₃

State the name of the element or radical given below

SO₃

State the valency of the element or radical given below

SO₃

State the name of the element or radical given below

SO₄

State the valency of the element or radical given below

SO₄

State the name of the element or radical given below

PO₄

State the valency of the element or radical given below

PO₄

State the name of the element or radical given below

N

State the valency of the element or radical given below

N

State the name of the element or radical given below

C

State the valency of the element or radical given below

C

State the name of the element or radical given below

PO₃

State the valency of the element or radical given below

PO₃

State the name of the element or radical given below

Al

State the valency of the element or radical given below

Al

State the name of the element or radical given below

Ca

State the valency of the element or radical given below

Ca

State the name of the element or radical given below

H

State the valency of the element or radical given below

H

State the name of the element or radical given below

PbO₂

State the valency of the element or radical given below

PbO₂

State the name of the element or radical given below

HSO₃

State the valency of the element or radical given below

HSO₃

State the name of the element or radical given below

AlO₂

State the valency of the element or radical given below

AlO₂

State the name of the element or radical given below

Cr

State the valency of the element or radical given below

Cr

State the name of the element or radical given below

HSO₄

State the valency of the element or radical given below

HSO₄

State the name of the element or radical given below

NH₄

State the valency of the element or radical given below

NH₄

State the variable valencies of the following element and give their name.

Cu

State the variable valencies of the following element and give their name.

Ag

State the variable valencies of the following element and give their name.

Hg

State the variable valencies of the following element and give their name.

Fe

State the variable valencies of the following element and give their name.

Pb

State the variable valencies of the following element and give their name.

Sn

State the variable valencies of the following element and give their name.

Mn

State the variable valencies of the following element and give their name.

Pt

State the variable valencies of the following element and give their name.

Au

State if the following element or radical is divalent?

Lithium

State if the following element or radical is divalent?

Nickel

State if the following element or radical is divalent?

Ammonium

State if the following element or radical is divalent?

Bromide

State if the following element or radical is divalent?

Sulphite

State if the following element or radical is divalent?

Nitride

State if the following element or radical is divalent?

Carbide

State if the following element or radical is divalent?

Chromium

State if the following element or radical is divalent?

Bisulphite

State if the following element or radical is divalent?

Dichromate

State if the following element or radical is divalent?

Permanganate

Explain the meaning of the term ‘compound’ with a suitable example.

State the main characteristics of a compound with special reference to the compound iron [II] sulphide.

Name the element in the compound and give the formula of the following compound:

Nitric acid

Name the element in the compound and give the formula of the following compound:

Carbonic acid

Name the element in the compound and give the formula of the following compound:

Phosphoric acid

Name the element in the compound and give the formula of the following compound:

Acetic acid

Name the element in the compound and give the formula of the following compound:

Blue vitriol

Name the element in the compound and give the formula of the following compound:

Green vitriol

Name the element in the compound and give the formula of the following compound:

Glauber’s salt

Name the element in the compound and give the formula of the following compound:

Ethane

Name the element in the compound and give the formula of the following compound:

Ethanol

Explain the terms ‘chemical formula’.

State why the molecular formula of zinc carbonate is ZnCO₃ .

Write the formula of the following compound:

Potassium dichromate

Write the formula of the following compound:

Potassium permanganate

Write the formula of the following compound:

Potassium zincate

Write the formula of the following compound:

Potassium plumbite

Write the formula of the following compound:

Potassium sulphate

Write the formula of the following compound:

Potassium bicarbonate

Write the formula of the following compound:

Potassium aluminate

Write the formula of the following compound:

Potassium hydroxide

Write the formula of the following compound:

Potassium iodide

Write the formula of the following compound:

Potassium nitrite

Write the formula of the following compound:

Potassium bisulphite

Write the formula of the following compound:

Sodium chloride

Write the formula of the following compound:

Sodium nitrate

Write the formula of the following compound:

Sodium carbonate

Write the formula of the following compound:

Sodium bisulphate

Write the formula of the following compound:

Sodium sulphite

Write the formula of the following compound:

Sodium dichromate

Write the formula of the following compound:

Sodium permanganate

Write the formula of the following compound:

Sodium zincate

Write the formula of the following compound:

Sodium plumbite

Write the formula of the following compound:

Sodium sulphate

Write the formula of the following compound:

Sodium bicarbonate

Write the formula of the following compound:

Sodium aluminate

Write the formula of the following compound:

Sodium hydroxide

Write the formula of the following compound:

Sodium iodide

Write the formula of the following compound:

Sodium nitrite

Write the formula of the following compound:

Sodium bisulphite

Write the formula of the following compound:

Calcium chloride

Write the formula of the following compound:

Calcium nitrate

Write the formula of the following compound:

Calcium carbonate

Write the formula of the following compound:

Calcium bisulphite

Write the formula of the following compound:

Calcium sulphite

Write the formula of the following compound:

Calcium sulphate

Write the formula of the following compound:

Calcium bicarbonate

Write the formula of the following compound:

Calcium hydroxide

Write the formula of the following compound:

Magnesium chloride

Write the formula of the following compound:

Magnesium nitrate

Write the formula of the following compound:

Magnesium carbonate

Write the formula of the following compound:

Magnesium sulphate

Write the formula of the following compound:

Magnesium bicarbonate

Write the formula of the following compound:

Magnesium hydroxide

Write the formula of the following compound:

Magnesium oxide

Write the formula of the following compound:

Zinc chloride

Write the formula of the following compound:

Zinc nitrate

Write the formula of the following compound:

Zinc carbonate

Write the formula of the following compound:

Zinc sulphate

Write the formula of the following compound:

Zinc hydroxide

Write the formula of the following compound:

Zinc oxide

Write the formula of the following compound:

Zinc oxide

Write the formula of the following compound:

Aluminium chloride

Write the formula of the following compound:

Aluminium nitrate

Write the formula of the following compound:

Aluminium carbonate

Write the formula of the following compound:

Aluminium sulphate

Write the formula of the following compound:

Aluminium hydroxide

Write the formula of the following compound:

Aluminium hydroxide

Write the formula of the following compound:

Aluminium oxide

Write the formula of the following compound:

Copper [I] chloride

Write the formula of the following compound:

Copper [II] chloride

Write the formula of the following compound:

Copper [I] oxide

Write the formula of the following compound:

Copper [II] oxide

Write the formula of the following compound:

Copper [I] sulphide

Write the formula of the following compound:

Copper [II] sulphide

Write the formula of the following compound:

Copper [II] nitrate

Write the formula of the following compound:

Copper [II] sulphate

Write the formula of the following compound:

Tetra amine copper [II] sulphate

Write the formula of the following compound:

Iron [II] chloride 

Write the formula of the following compound:

Iron [III] chloride 

Write the formula of the following compound:

Iron [II] oxide

Write the formula of the following compound:

Iron [III] oxide

Write the formula of the following compound:

Iron [II] sulphate

Write the formula of the following compound:

Iron [III] sulphate

Write the formula of the following compound:

Iron [II] sulphide

Write the formula of the following compound:

Iron [III] sulphide

Write the formula of the following compound:

Iron [II] hydroxide

Write the formula of the following compound:

Iron [III] hydroxide

Write the formula of the following compound:

Lead [II] chloride

Write the formula of the following compound:

Lead [II] oxide

Write the formula of the following compound:

Lead [II] hydroxide

Write the formula of the following compound:

Lead [II] nitrate

Write the formula of the following compound:

Lead [II] sulphate

Write the formula of the following compound:

Silver [I] chloride

Write the formula of the following compound:

Silver [II] chloride

Write the formula of the following compound:

Diamine silver chloride

Write the name of the following compound:

KClO

Write the name of the following compound:

HClO

Write the name of the following compound:

NaClO₃ 

Write the name of the following compound:

AIN 

Write the name of the following compound:

K₂Cr₂O₇ 

Write the name of the following compound:

KMnO₄ 

Write the name of the following compound:

Ca₃N₂ 

Write the name of the following compound:

Ca₃(PO₄)₂ 

Write the name of the following compound:

H₂SO₃ 

Write the name of the following compound:

HCl

Write the name of the following compound:

HNO₃ 

Write the name of the following compound:

H₂SO₄ 

Write the name of the following compound:

NH₄OH

Write the name of the following compound:

NaOH

Write the name of the following compound:

H₂CO₃ 

Write the name of the following compound:

HNO₂ 

Write the name of the following compound:

Mg(HCO₃)₂ 

Write the name of the following compound:

NaAlO₂ 

Write the name of the following compound:

K₂PbO₂ 

Write the name of the following compound:

Cr₂(SO₄)₃ 

Write the name of the following compound:

Na₂O

Explain the term ‘chemical equation’.

What is meant by ‘reactants’ and ‘products’ in a chemical equation?

Give an example of a chemical equation in which two reactants form:

one product

Give an example of a chemical equation in which two reactants form:

two product

Give an example of a chemical equation in which two reactants form:

three product

Give an example of a chemical equation in which two reactants form:

four product

\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]

State what is a ‘balanced equation’.

\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]

Give a reason why the above equation is balanced.

\[\ce{2KClO3->[MnO2] 2KCl + 3O2[g] - is a balanced equation.}\]

State why the compound MnO₂ is written above the arrow.

What does the symbol '→' present in a chemical equation, mean?

What does the symbol '⇌' present in a chemical equation, mean?

What does the symbol '(s)' present in a chemical equation, mean?

What does the symbol '(l)' present in a chemical equation, mean?

What does the symbol '(g)' present in a chemical equation, mean?

What does the symbol '(aq.)' present in a chemical equation, mean?

CaCO3 + 2HCl[dil.] → CaCl₂ + H₂O + CO₂ [g]

State the information provided by the above chemical equation.

CaCO₃ + 2HCl[dil.] → CaCl₂ + H₂O + CO₂ [g]

State the information not conveyed by the above chemical equation. 

Balance the following simple equation:

C   +   O₂  →  CO

Balance the following simple equation:

N₂   +   O₂  ⇌  NO

Balance the following simple equation:

ZnS   +   O₂  →  ZnO + SO₂ 

Balance the following simple equation:

Al   +   O₂  →  Al₂O₃ 

Balance the following simple equation:

Mg   +   N₂  →  Mg₃N₂ 

Balance the following simple equation:

Al   +   N₂  →  AlN 

Balance the following simple equation:

NO   +   O₂  →  NO₂ 

Balance the following simple equation:

SO₂   +   O₂  ⇌  SO₃ 

Balance the following simple equation:

H₂   +   Cl₂  →  HCl

Balance the following simple equation:

Fe   +   Cl₂  →  FeCl₃ 

Balance the following simple equation:

H₂S   +   Cl₂  →  S  +  HCl 

Balance the following simple equation:

FeCl₂   +   Cl₂  →  FeCl₃ 

Balance the following simple equation:

CO₂   +   C  →  CO 

Balance the following simple equation:

KHCO₃ →  K₂CO₃   +    H₂O   +   CO₂

Balance the following simple equation:

K   +   CO₂   →    K₂O   +   C

Balance the following simple equation:

\[\ce{Ca(OH)2 + HNO3 -> Ca(NO3)2 + H2O}\]

Balance the following simple equation:

K  +   H₂O   →   KOH   +   H₂ 

Balance the following simple equation:

Ca  +   H₂O   →   Ca(OH)₂   +   H₂ 

Balance the following simple equation:

Al  +   H₂O   →   Al₂O₃   +   H₂ 

Balance the following simple equation:

Fe  +   H₂O  ⇌   Fe₃O₄   +   H₂ 

Balance the following simple equation:

Zn  +   NaOH  →   Na₂ZnO₂   +   H₂ 

Balance the following simple equation:

Zn  +   HCl  →   ZnCl₂   +   H₂ 

Balance the following simple equation:

Al  +   H₂SO₄  →   Al₂(SO₄)₃   +   H₂ 

Balance the following simple equation:

H₂  +   O₂  →   H₂O

Balance the following simple equation:

\[\ce{N2 + H2 <=> NH3}\]

Balance the following simple equation:

Fe₂O₃  +  H₂  → Fe  +  H₂O

Balance the following simple equation:

KBr  +  Cl₂  → KCl  +  Br₂

Balance the following simple equation:

NaOH  +  Cl₂  →  NaCl  +   NaClO  +  H₂O 

Balance the following simple equation:

NaHCO₃  +  H₂SO₄  →  Na₂SO₄  +  H₂O  +  CO₂ 

Balance the following simple equation:

Mg  +  CO₂  →  MgO  +  C

Balance the following simple equation:

Fe₂O₃  +  CO  →  Fe  +  CO₂ 

Balance the following simple equation:

CaO  +  HCl  →  CaCl₂  +  H₂O 

Write a balanced equation for the following word equation:

Potassium nitrate → Potassium nitrite + Oxygen

Write a correctly balanced equation for the following “word equation”:
calcium + water → calcium hydroxide + hydrogen

Write a balanced equation for the following word equation:

Iron + Hydrochloric acid → Iron [II] chloride + Hydrogen

Write a balanced equation for the following word equation:

Nitrogen dioxide + Water + Oxygen → Nitric acid

Write a balanced equation for the following word equation:

Lead dioxide [lead (IV) oxide] → Lead monoxide + Oxygen 

Write a balanced equation for the following word equation:

Aluminium + Oxygen → Aluminium oxide 

Write a balanced chemical equation for the following word equation:

Iron + Chlorine → Iron (III) chloride

Write a balanced equation for the following word equation:

Potassium bromide + Chlorine → Potassium chloride + Bromine

Write a balanced equation for the following word equation:

Potassium bicarbonate → Potassium carbonate + Water + Carbon dioxide 

Write a balanced equation for the following word equation:

Calcium hydroxide + Ammonium chloride → Calcium chloride + Water + Ammonia

Balance the following important equation:

NaHCO₃ + H₂SO₄ → Na₂SO₄ + H₂O + CO₂ 

Balance the following important equation:

NaOH + H₂SO₄ → Na₂SO₄ + H₂O 

Balance the following important equation:

Pb(NO₃)₂ + NaCl → NaNO₃ + PbCl₂ 

Balance the following important equation:

FeSO₄ + NaOH → Na₂SO₄ + Fe(OH)₂ 

Balance the following important equation:

FeCl₃ + NaOH → NaCl + Fe(OH)₃

Balance the following important equation:

CuSO₄ + NaOH → Na₂SO₄ + Cu(OH)₂  

Balance the following important equation:

FeCl₃ + NH₄OH → NH₄Cl + Fe(OH)₃  

Balance the following important equation:

ZnO + NaOH → Na₂ZnO₂ + H₂O  

Balance the following important equation:

Pb(OH)₂ + NaOH → Na₂PbO₂ + H₂O  

Balance the following important equation:

Al₂O₃.2H₂O + NaOH → NaAlO₂ + H₂O  

Balance the following important equation:

NaAlO₂ + H₂O  → NaOH  + Al(OH)₃ 

Balance the following important equation:

\[\ce{Al(OH)3 -> Al2O3 + H2O}\]

Balance the following important equation:

ZnS  + O₂  → ZnO + SO₂ 

Balance the following important equation:

Fe₂O₃  + Al  → Al₂O₃ + Fe

Balance the following important equation:

Al + Cl₂  → AlCl₃ 

Balance the following important equation:

NaCl + H₂SO₄  → Na₂SO₄ + HCl  

Balance the following important equation:

Fe + HCl  → FeCl₂ + H₂  

Balance the following important equation:

Na₂CO₃ + HCl → NaCl + H₂O + CO₂ 

Balance the following important equation:

Pb(NO₃)₂ + HCl → PbCl₂ + HNO₃ 

Balance the following important equation:

\[\ce{AgCl + NH4OH -> Ag(NH3)2Cl + H2O}\]

Balance the following important equation:

MnO₂ + HCl → MnCl₂ + H₂O + Cl₂ 

Balance the following important equation:

\[\ce{Pb3O4 + HCl -> PbCl2 + H2O + Cl2}\]

Balance the following important equation:

KMnO₄ + HCl → KCl + MnCl₂ + H₂O + Cl₂ 

Balance the following important equation:

K₂Cr₂O₇ + HCl → KCl + CrCl₃ + H₂O + Cl₂ 

Balance the following important equation:

\[\ce{NH4Cl + Ca(OH)2 → CaCl2 + H2O + NH3}\]

Balance the following important equation:

(NH₄)₂SO₄ + NaOH → Na₂SO₄ + H₂O + NH₃

Balance the following important equation:

Mg₃N₂ + H₂O → Mg(OH)₂ + NH₃

Balance the following important equation:

AIN + H₂O `→` Al(OH)₃ + NH₃

Balance the following important equation:

NH₃ + O₂ → N₂ + H₂O (burning of NH₃) 

Balance the following important equation:

NH₃ + O₂ → NO + H₂O (catalytic oxidation of  NH₃) 

Balance the following important equation:

NH₄OH + H₂SO₄ → (NH₄)₂SO₄ + H₂O 

Balance the following important equation:

NH₃ + CuO → Cu + H₂O + N₂ 

Balance the following important equation:

NH₃ + Cl₂ → HCl + NCl₃  [nitrogen trichloride]

Balance the following important equation:

HNO₃  → H₂O + NO₂ + O₂  

Balance the following important equation:

Ca(HCO₃)₂ + HNO₃  → Ca(NO₃)₂ + H₂O + CO₂ 

Balance the following important equation:

C + HNO₃ (conc.) → CO₂ + H₂O + NO₂ 

Balance the following important equation:

S + HNO₃ (conc.) → H₂SO₄ + H₂O + NO₂ 

Balance the following important equation:

Cu + HNO₃ (conc.) → Cu(NO₃)₂ + H₂O + NO₂ 

Balance the following important equation:

C + H₂SO₄ (conc.) → CO₂ + H₂O + SO₂ 

Balance the following important equation:

S + H₂SO₄ (conc.) → SO₂ + H₂O 

Balance the following important equation:

Cu + H₂SO₄ (conc.) → CuSO₄ + H₂O + SO₂  

Give a balanced equation by partial equation method, [steps are given below].

The reaction of excess ammonia with chlorine – Ammonia as a reducing agent

1. Ammonia first reacts with chlorine to give hydrogen chloride and nitrogen.
2. Hydrogen chloride then further reacts with excess ammonia to give ammonium chloride.

Give a balanced equation by the partial equation method, [steps are given below].

Oxidation of Lead [II] Sulphide by Ozone

1. Ozone first decomposes to give molecular oxygen & nascent oxygen.
2. Nascent oxygen then oxidises lead [II] sulphide to lead [II] sulphate. 

Define the term Relative atomic mass. State why indirect methods are utilised to determine the absolute mass of an atom. Explain in brief the indirect method used.

Define the term Relative molecular mass. State why indirect methods are utilised to determine the absolute mass of an atom. Explain in brief the indirect method used.

Calculate the relative molecular mass of CaSO₄ [Zn = 65, S=32, O = 16, Ca = 40, C = 12]

Calculate the relative molecular mass of ZnCO₃.

Calculate the percentage composition of calcium chloride.

Calculate the percentage composition of calcium nitrate [Ca = 40 , Cl = 35.5 , N = 14 , O = 16]

Match the names of ions and radicals from 1 to 10 with their correct answer from A to Q.

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

(NH₄)₃SO₄

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

NaZnO₂

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

KCr₂O₇

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

NaCO₃

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

Ca₂(PO₄)₃

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

Mg(SO₄)₂

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

KNO₃

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

NaClO

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

NaO

State of the following formula of a compound is incorrect. Incorrectly write the correct formula.

BaCl₂

Fill in the blank with the correct word from the  options given below:

A symbol represents a short form of a / an ________.

Fill in the blank with the correct word from the options given below:

Compounds are always _______ in nature.

Fill in the blank with the correct word from the options given below:

Variable valency is exhibited since electrons are lost from an element from the __________ shell.

Fill in the blank with the correct word from the options given below:

A chemical equation is a shorthand form for a _______ change.

Fill in the blank with the correct word from the options given below:

Relative molecular mass of an element/compound is the number of times one ________ of the substance is heavier than −1/12that the mass of an atom of carbon [C₁₂].

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

Na₂SO₃ + HCl → 2NaCl + H₂O + SO₂

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

CaC₂ + N₂ → 2CaCN₂ + C

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

Fe₂O₃ + 2H₂ → 2Fe + 3H₂O

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

Cl₂ + 2H₂O + SO₂ → 4HCl + H₂SO₄

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

6NaOH + 3Cl₂ → 6NaCl + NaClO₃ + 3H₂O

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

C₂H₅OH + 3O₂ → 2CO₂ + 2H₂O

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

NaOH + CO₂ → Na₂CO₃ + H₂O

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

2H₂O + 2Cl₂ → 2HCl + O₂

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

3CuO + NH₃ → 3Cu + 3H₂O + N₂

Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.

PbO₂ +4HCl → PbCl₂ + H₂O + Cl₂

With reference to a chemical equation state which of the statements 1 to 5 pertain to A or B.
A: Information provided by a chemical equation. 
B: Limitations of a chemical equation.

1. The nature of the individual elements.
2. The speed of the reaction.
3. The state of matter in which the substance is present.
4. The completion of the reaction.
5. The direction of the reaction.