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# Chapter 1 Basic Concepts in Chemistry – FSc Part 1 Chemistry Notes

Chapter 1 Basic Concepts in Chemistry – FSc Part 1 Chemistry Notes

Formula of mass spectrograph:
(The formula of mass charge ratio for mass spectrograph is m/e = to H2 R2/2, where ‘H’ is the strength of magnetic field. E is the strength of electrical field and R is the radius of curvature of positive ion.
EQUATION TO SOLVE THE NUMERICALS

1. Empirical and Molecular Formula
i. Average atomic mass of an element = Sum of multiplication and isotopic mass and relative abundance / 100

ii. % composition of element in a compound
= Mass of element × 100 / mass of the compound

iii. The % of C, H and O is an organic compound is determined by combustion analysis. The formula is as follows:

% of Carbon = Mass of CO2 Mass of organic compound × 12 × 100 / 44

% of hydrogen = Mass of H2O / Mass of organic compound × 2 × 100 / 18

% of oxygen = 100- (% of C + % of H)

iv. Molecular formula = n( empirical formula)

2. Concept of Mole and Avogadro’s Number
Mole:
The atomic mass of an element, molecular mass of a molecule or formula mass of a formula unit, expressed in grams, is called one mole of that element, molecule or formula unit, e.g Gram At. Mass of O= 16 g = 1 mole oxygen element.
N= 14 g= 1 mole of N element,
Na= 23g= 23g = 1 mole of Na element
H= 1g = 1 mole of H element

Similarly :
Gram Molecular mass of O =16 g = 1 mole oxygen element.
N = 14g = 1 mole of n element.
Na = 23 g = 1 mole of Na element.
H = 1g = 1 mole of H element.

Similarly:
Gram Molecular Mass of H2O = 18 g = 1 mole of H2O molecules
HCL = 36.5 g = 1 mole of HCL molecules.
O2 = 32g = 1 mole of O2 molecules

Similarly:
Gram formula Mass of NaCL = 58.5g = 1 mole of NaCL formula units.
MgO = 40 g = 1 mole of MgO formula units.

No of moles of a substance ( element, molecule or formula unit) is represented by “ n” & can be calculated by the following formulas.

Examples:
What is the no of moles (or gram atoms of 0.1 of g on Na.
No of moles of Na (n Na) = ?
Mass of Na (m Na) = 0.1 g
Solution:
n = Mass (g) of Na / At Mass of Na
n = 0.1/23
n = 0.0043 moles or 4.3*10-3

As one dozen of eggs , one dozen of bananas and one dozen of oranges have fixed no. of items (eggs, bananas & oranges) although they have different masses, different fast and different nature , likewise it the case for one mole of a substance ( element, molecule or formula unit ).
So we can say that : one mole of any substance contains a fixed no of particles. This fixed no, is called Avogadro No. it is represented by “Na” and its value is 6.023*1023.
For example:
1 mole ( 23g) of Na element = 6.023*1023 Na atoms.
1 mole ( 1.008g ) of H element = 6.023*1023 H atoms.
1 mole ( 16g ) of oxygen element = 6.023*23 O atoms.

Similarly
1 mole ( 18g ) of H2O Molecule = 6.023* H2O Molecule.
1 mole ( 32 ) of O2 Molecule = 60023*1023 O2 Molecule.
1 mole ( 58.5g ) of NaCl formula unit.= 6.023*1023 NaCl formula units.
1 mole of Na+ = 6.023*1023 Na+ ions
1 mole of Cl-= 6.023*1023 Cl- ions.

The substances which combine to undergo chemical reaction & whose bonds are broken are called the “Reactants” while the substances which are formed as a result of chemical reaction are known as products.

METHODS TO SOLVE THE NUMERICAL PROBLEMS
1. Determination of average atomic mass of an element from the % relative abundance and isotopic message
The % relative abundance of each isotope is multiplied with isotopic mass. These factors are added app for all the isotopes and divided by 100..
2. Determination of % an element in a compound
The mass of the element in the compound is divided by the molar mass of the compound and multiplied by 100.
3. Determination of Empirical Formula
The % of each element is divided by the atomic mass to get the molecule ratios. The mole ratios are divided by the smallest value to get the atomic ratios. If the atomic ratio are whole numbers, then well and good, otherwise multiply with the suitable digit to get the whole numbers. These whole numbers give the empirical formulas.
4. Determination of Molecular Formula from Empirical Formula
For this purpose, we should know the moral mass of the compound. Molar mass is divided by empirical formula mass to get the ‘n’ factor.
‘N’ is multiplied with empirical formula to get the molecule formula.
5. Calculation of mole of a substance
Number of moles of element are obtained to divide dividing the mass of the element with atomic mass.
In case of molecular compounds, the mass of the substance is divided by molar mass to get the number of moles of the compound.
6. Calculation of numbers of atoms
To calculate the number of atoms of an element divide the mass of the element by atomic mass and multiply with NA.
7. Stoichiometric calculation the number of molecules
To calculate the number of molecules of a compound divide mass of the compound by molar mass and multiplied with NA.
8. Stoichiometric Calculation
In stoichiometric calculation, the mass of the given substance is converted into number of moles. These moles are compared with the moles of the substance whole amount is required. For the purpose of comparison, we take the help of balanced chemical equation.
9. Calculation of limiting reagent
To calculate limiting reagent, with first of all calculate the number of moles of all the reactant whose masses are given. This number of moles are compared with numbers of moles of the required substance. That substance among the reactants which gives lesson number of moles of the required product is the limiting reagent. The less number of moles of the required product is multiplied by molar mass to get its mass.
10. Calculation of % Yield
In order to calculate the % yield of a chemical reaction we need to actual Yield. This is the most given in the numerical. The theoretical yield is calculated from the balanced chemical equation according to the discipline of stoichiometry.
DEFINITIONS.
1. % Yield
The Yield which is obtained by dividing the actual yield with theoretical yield and multiplying with 100 is called % age. It is calculated for knowing the efficiency of a chemical reaction. Formula!
Yield % = (Actual yield/theoretical yield) x 100
2. Actual Yield
The actual amount of the product which is obtained in a chemical reaction is called actual yield. It is an experimental quantity and it is mostly less than theoretical yield. Theoretical yield is calculated from the balanced chemical reaction. We take the help of stoichiometry for calculating theoretical yield.
3. Atom
The smallest particle of matter which may or may not have free existence is called atom, For example hydrogen element is composed of H atoms which don’t have free existence. Similarly Helium element is composed of He atoms which have free existence.
4. Atomic-mass-unit ( AMU)
It is mass of 1/12th of one atomic of carbon with lightest isotope C -12. Its value is 1.661 × 10.24 kg. It is calculated with the help of Avogadro number.
5. Average atomic mass
The average of the atomic masses of all the isotopes of an element with respect t their relative abundance is known as average atomic mass of that element for the determination of the average atomic mass of an element we multiply the masses of all the isotopes with relative abundance and then add then up and finally divide them by 100.
1 mole ( 23g) of Na element = 6.023*1023 Na atoms.
1 mole ( 1.008g ) of H element = 6.023*1023 H atoms.
1 mole ( 16g ) of oxygen element = 6.023*23 O atoms.
7. Branches of chemistry
Organic Chemistry
Inorganic Chemistry
Physical Chemistry
Analytical Chemistry
Biochemistry
Industrial Chemistry
Nuclear Chemistry
Environmental Chemistry

8. Chemistry

Is that branch of science which deals with the properties, compositions and structure of matter, changes occurring in matter and the laws under which these changes occur.
9. Empirical formula
The formula of a substance which gives a simple ratio of the element present in the molecule of a substance. The empirical formula
10. Gram atom
The atomic mass of an element express in grams is called the gram atom of an element 12 g of carbon, 56g of Fe and 238 g of U are gram atoms of carbon, iron and uranium respectively.
11. Gram formula
The formula mass of an ionic substance expressed in grams is called as gram formula of the substance. 58.5 g of NaCl is gram formula of NaCI. It is not its molecular formula and does not have molecules.
12. Ion
When an atom loses or gains one or more electrons have 8 electrons in their outermost (valence ) shell, they get a tire of –ve sign. This positively or negatively changed species is known as ion.
e.g.
Electron configuration of
Na is K=2 , l=8, M=1
The ion having negative change is called “Anion “. It is important to note that properties of ions are totally different from their corresponding neutral atoms. The ions may be a group of atoms like
-2 , Co3
-2, Hco3
-1 , no4
-1 , Cr2O7
-2, PO4
13. Isotopes
Isotopes of an element may be defined as:
“The atoms of an element having same atomic number but different atomic masses, are called isotopes of that elements.”
OR “Atoms of an element having same no. of protons and same no. of electrons but different no. of neutrons are called isotopes of that elements.
OR ” Atoms of an element having same chemical properties but different physical properties are called isotopes of that element.

For example carbon element has three isotopes. Which are known as C-12, C-13, & C-14.
14. Limiting reactant
the reactant which is present in lesser amount and control the amount of the product formed is called limiting reactant. It is finished earlier.
15. Macromolecules
Molecules of high molar masses usually more than 10,000 are called macromolecules. The molecules of PVC, starch and cellulose are macromolecules.
16. Mass spectrometry
It is a technique in which gas molecules are converted to gaseous ions, which are separated on the basis of their mass to change ratio. It may be for isotopes of an element or to see the fragmentation pattern of a molecule. The isotopes of an it can be separated by it.
17. Mass spectrum
It is a graphical representation of the masses and the relative abundances of molecule station. The positively charged fragments are formed from it by the electron bombardment. It shows peaks. The of fragment is calculated from the base peak.
18. Mole
The atomic mass of an element, molecular mass of a molecule or formula mass of a formula unit, expressed in grams, is called one mole of that element, molecule or formula unit, e.g Gram At. Mass of O= 16 g = 1 mole oxygen element.
N= 14 g= 1 mole of N element,
Na= 23g= 23g = 1 mole of Na element
H= 1g = 1 mole of H element
19. Relative abundance of an isotope
The no of atoms of an isotopes of an element present in 100 atoms of element is known as relative abundance of that isotope.
Eg if we take 100 atoms of Hydrogen element & let the no of protium atoms is 97 that of deuterium atoms is 2 and that of tritium, atoms is 1. Thus we can say that the relative abundance of protium is 97% , Deuterium is 2% and tritium is 1 % .
20. Relative atomic mass
The mass of one atom of an detail in comparison with the mass of one atom of carbon – 12 is known as relative atomic mass of that detail. Carbon- 12 ( C-12 ) that is an isotopes of carbon detail and it is considered as general. It mass is considered as precisely 12 a.m. u The masses of all the other elements are compared with the mass of C- 12 which might be known as their relative atomic mass.

The unit of atomic mass is a. m. u ie atomic mass unit.
21. Stoichiometric amounts
The branch of chemistry which deals with the study of relationship between the quantities of reactants and products is called stoichiometry. It is based on two laws.
23. Molecular formula
The formula of a compound which shows the actual no of atoms of its element is called as molecular formula of that compound. Molecular Formula Benzene C6H6 Glucose C6H12O6 Water H2O
24. Molecular mass
It is the sum of the atomic masses of all the elements present in the molecular formula of a molecule.
e.g : The molecular formula of benzene is C6H6. Thus its molecular mass is 12*6+1*6===== 78a. m. u or 78g/ mole.
25. Polyatomic molecule
A molecule having more than two atoms is called polyatomic molecule.
26. Relative abundance of an isotope
The no of atoms of an isotopes of an element present in 100 atoms of element is known as relative abundance of that isotope.
Eg if we take 100 atoms of Hydrogen element & let the no of protium atoms is 97 that of deuterium atoms is 2 and that of tritium, atoms is 1. Thus we can say that the relative abundance of protium is 97% , Deuterium is 2% and tritium is 1 % .
27. Stoichiometry
The branch of chemistry which deals with the quantitative relationship between reactants and products in a balanced chemical equation is called stoichiometry.
28. Yield
The amount of products obtained is known as yield.
29. Theoretical yield
The amount of products calculated from a stoichiometric equation is known as theoretical yield.
30. Actual Yield
The amount of products obtained during chemical reaction or experiment is called actual yield.

Long Notes
Science
The study of all the things of universe is called science.
Or
The knowledge based on observations experiments and results is called science.

At the beginning, science was named as Natural Philosophy and it had two branches.
1.Biological Science
2.Physical Science
Biological Science
As there are simplest styles of residing matters from the start ie Animals and plants, so biological science were given two major farther topics ie Botany ( from Greek word Botany —–Herbs study plants ). Zoology ( from Greek phrase Zoo — Animal ).
Physical Science
On the other hand with the passage of time more and more development took place, in physical science, therefore it is divided into the following main branches . Physics ,Chemistry, Math, Computer Astronomy etc.
Matter:
Anything which has mass and volume is called matter
Or
Anything having mass and volume is called matter e.g Pen, Air, Water, etc
States of matter.
1.Solid state
2.Liquid state
3.Gaseous state
4.Plasma state
Chemistry:
Is that branch of science which deals with the properties, compositions and structure of matter, changes occurring in matter and the laws under which these changes occur.
Branches of Chemistry:
With the passage of time, increasingly more development passed off in chemistry, therefore it become felt essential to divide chemistry into various branches to make its study more handy and systematic, chemistry has been divided into the following important branches..
Organic Chemistry:
The carbon containing compounds ( besides CO2, CO, CO3 -2, HCO3- 1 & CN ) are called organic compounds and their have a look at is known as organic chemistry.
Inorganic Chemistry:
The study of all the factors and compounds of the elements aside from carbon is known as inorganic chemistry.
Physical Chemistry:
The branches of chemistry managing the study of laws and standards which might be accountable for the separation and mixture of atoms all through chemical reaction called physical chemistry.
Analytical Chemistry:
The study of qualitative and quantitative evaluation of a substance is called analytical chemistry.
Biochemistry:
The study of chemical reactions place inside the body of living things is called biochemistry.
Industrial Chemistry:
The study of chemical reactions occurring during the formation of various synthetic products like content, glass, plastic etc in industries is called industrial chemistry.
Nuclear Chemistry:
The study of changes occurring in the nuclei of radio active elements as a result of spontaneous emission of radiations & their effects is called nuclear chemistry.
Environmental Chemistry:
The study of chemical reactions taking place in the environment and their effects upon us is called environmental chemistry.

Atom:
The smallest particle of matter which may or may not have free existence is called atom, For example hydrogen element is composed of H atoms which don’t have free existence. Similarly Helium element is composed of He atoms which have free existence.
The word Atom is derived from a Greek word, Atoms which means indivisible. This name was given by Democritus / 460-370 B.C. Actually the Greek, philosophers thought that matter could be divided into smaller and smaller particles to into smaller and smaller particles to reach a basic unit, that can not be further sub-divided. According to the modern concepts, atom is further composed of sub-atomic particles which are more than 100. however there are the fundamental ones they are:
1.Proton
2.Electron
3.Neutron
All of the debris of an atom are in the nucleus of it. only electrons are present outside, the nucleus, revolving round it. A Swedish chemist. Named as J. Berzelius ( 1779-1848) decided the atomic masses of factors. He also furnished the system of giving symbols to elements.
Elements:
Element is a pure substance, which is composed of chemically identical atoms. e.g.; hydrogen is an element which consists of it atoms which are all chemically identical y the term chemically.
Substance:
Any pure matter which a uniform composition is known as substance. e.g.; elements, compound, molecule etc.
Identical means that all atoms of an element will have same number of protons and same no. of electrons. However their number of neutrons mean be different.
H –> element H,H,H,H,H,H —> Atoms
So far more than 110 elements are known. Most of them are natural while some are synthetic,
Types:- Elements are of the following three types.
1.Metals
2.Non-metals
3.Metalloids
Metals
They are hard solids excepts Hg which is liquid
There have shine
They are good conductors of heart & electricity
Some metals are ductile i.e.; their wires can be format
They have light melting point & boiling point.
Examples Na, K, Mg, Cu, Ag, Au, Me etc.

Non-Metals:
They may be solid, liquid or gases
They have no shine
They are bad conductors except graphite
Non-metals are brittle, i.e.; their & some are malleable i.e.; their sheets can be formed wires & sheets cannot be formed.
They have low melting point & boiling point.
Examples i. Sold:- C, S, P etc ii. Liquid:- Br. iii. Gas:- H2, U2, O2 etc.

Metalloids:
The elements which have properties in between metals and non-metals. e.g.; Ga, Ge. Etc.

Compound:
When atoms of or greater elements chemically integrate in a fixed ratio, a new substance is formed. that is called compound.
For example when atoms of hydrogen element chemically integrate with one atom of oxygen element, a compound, water (H2O) is formed in which the atoms are combined in 2:1
Molecule:
The smallest particle of a substance which is capable of free existence is known as molecule. e.g.; H2O, H2, O2 etc.
Classification of Molecules:
Molecules can be classified in two ways as:

On the basis of nature of elements:
On the basis of nature of elements, there are two types of molecule
1.Molecule of Elements The molecules that are made of atoms of equal elements. e.g.H2, O2, O3, S8, P4, N2, U2 etc.
2.Molecule of Compound: The molecules which might be manufactured from atoms of various elements. e.g.: H2O, H2, SO4, C6H12 06 and so on.
On the basis of number of atoms.
On the basis of no. of atoms there are three types of molecules, which are described as follow.

1.Mono-atomic molecules: The molecules which are made of only one atom are called mono-atomic molecules. e.g.; He, Ne, Xe etc.
2.Diatomic molecules: The molecules which are made of only two atoms (same or different). e.g.; H2, N2, CO,  U2 etc.
3.Poly atomic molecules: The molecules which are made of more than two atoms are called ply atomic atoms are called poly atomic molecules. e.g.; H2O, H2 SO4, C6 H12O6, CH4, NH3 etc.

Formula Unit:
The best mixture of atoms of a compound which possesses all the known as formula unit. for example NaU is a formula unit. Sodium chloride is a cluster of NaT & U Ions and each U ion is surrounded by 6 NaT & U ions of sodium chloride there’s no independent NAu Unit. consequently, NaU is named as formula unit instead of molecule. All ionic compounds are represented by formula units.
Isotopes:
Isotopes of an element can be defined as:
“The atoms of an element having identical atomic number however different atomic masses, are referred to as isotopes of that elements.”
OR “Atoms of an element having same no. of protons and same no. of electrons but distinctive no. of neutrons are known as isotopes of that elements. OR ” Atoms of an element having same chemical properties but different physical properties are called isotopes of that element.
For example carbon element has 3 isotopes. which might be called C-12, C-13, & C-14. these kinds of isotopes of carbon have equal no. of protons (e.g.; b) & equal no. of electron (i.e.;6) however different no. of neutrons i.e.; 6,7 and 8 respectively in C-12, C-13, & C-14. Other examples are, Hydrogen has 3 isotopes, oxygen has 3, Nickle ( Ni ) has 5, calcium has six, palladium has six, cadmium has 9 and tin has 2 isotopes.
Round approximately 280 natural isotopes are regarded 40 of them are radio active isotopes. Beside these280, about 300 unstable radio active artificial disintegration. Elements like Arsenic (As), fluorine (F), iodine ( I ) and gold ( Au ) etc, have best a single isotope. It essential to observe that elements of oddatomic number almost never possess more that two stable isotopes. Then again elements of even atomic number commonly have larger range of isotopes. The isotopes whose mass variety are more than one of 4, are specifically considerable out of 280 isotopes that occur in nature, 154 have even mass wide variety, or even atomic number.
Ion:
When an atom loses or gains one or more electrons have 8 electrons of their outermost (valence ) shell, they get a tire of –ve sign. This undoubtedly or negatively changed species is called ion.
e.g.
Electron configuration of
Na is k=2 , l=8, M=1
So sodium loses its single valence electron & therefore forms sodium ion ( Na+ ). Such an ion having + ve charge is called cation
Na ———————– Na+ + Ie-
2, 8
Similarly the electronic configuration on of 17CL is k=2, L=8, M=7 so it gains an electron to
form chloride ion ( Cl -1 )
i. e Cl + Ie- —————————- Cl-1
2, eight, 12
The ion having bad change is called “Anion “. it is essential to notice that properties of ions are totallydifferent from their corresponding impartial atoms. The ions can be a group of atoms like
-2 , Co3
-2, Hco3
-1 , no4
-1 , Cr2O7
-2, PO4
The + ve ion common e.g. NH4 + ion and a few carbon cations in natural chemistry.
Ion are continually solid inside their answer E.g.: Na+ & CL- ions are continually stable inside water.
Molecular Ion:
When a molecule loses or gains electron or electrons which is called molecular ion. e. g CH4 + , N2 + , CO+ etc. The cationic molecular ions ( +ve ) are more plentiful than the anionic ones. Molecular ions are fashioned with the aid of passing high pace electrons or x—particles via a gas.
Any negatively or positively charged species or a specie with unpaired electron, which is unable to have free existence is known as radical. e. g H. + CL. ( Neutral radicals with unpaired electron )

Atomic Number:
The no of protons or electrons found in an atom is known as atomic number of that element. for example there are 11 protons and 11 electrons in an atom of sodium element, therefore atomic mass of sodium is 11.

Atomic Mass or Mass No:
Sum of the protons and neutrons gift in the nucleus of an atom is known as the atomic mass of that atom.
e. g There are eleven protons and 12 neutrons inside the nucleus of Na atom, therefore the atomic mass of Na will be: 11 + 12 ======= 23 a. m. u
Relative Atomic Mass:
The mass of one atom of an element compared with the mass of one atom of corbon – 12 is called relative atomic mass of that element. Carbon- 12 ( C-12 ) which is an isotopes of carbon element and it is considered as standard. It mass is considered as exactly 12 a.m. u The masses of all the other elements are compared with the mass of C- 12 which are known as their relative atomic mass.

The unit of atomic mass is a. m. u ie atomic mass unit.

Atomic Mass Unit ( A. M. U )
It may be defined as the 12th part of the mass of an atom of C-12
Or
The mass of an atom of E-12 divided by 12 is known as one a. m. u. Let the mass of an atom of C-12 is Xg, then value of one a.m.u will be:
1 a. m. u = x = 12
E.g. : the mass of an atom of hydrogen id 0.084 times the mass of C-12, so the relative atomic mass of Hydrogen is 0.084* 12===1.008 a. m. u.
We can find the mass of one atom of C-12 as follow. As atomic mass of C-12 = 12g which is equal to one mole of carbon – 12 containing 6.023*1023 C-12 atoms i.e.
12g of C= 6.023 * 1023
1 a.m. u = 1.99*10-23/12
1 a.m. u = 1.66*10-24

Relative Molecular Mass:
Sum of the relative atomic masses of all the elements present in a molecule is called as relative molecular mass of that molecule. For example

FSc Chemistry MCQS Part 1
Chapter 1
Basic Concept in Chemistry
Choose the correct option.
(i) The mass of one mole of electrons is
a. Properties which depend upon mass
b.Arrangement of electrons in orbital
c. Chemical properties
d. The extent to which they may be affected in electromagnetic field
(ii) Which of the following statements is not true?
a. isotopes with even atomic masses are comparatively abundant
b. isotopes with odd atomic masses and even atomic number arecomparatively abundant
c.atomic masses are average masses of isotopes.
d. Atomic masses are average masses of isotopes proportional to their relative abundance
(iii) Many elements have fractional atomic masses, this is because
a. The mass of the atom is itself fractional
b. Atomic masses are average masses of isobars
c. Atomic masses are average masses of isotopes.
d. Atomic masses are average masses of isotopes proportional to their relative abundance
(iv) The mass of one mole of electrons is
a. 1. 008mg
b. 0.55mg
c. 0.184mg
d. 1.673mg
(v) 27g of Al will react completely with how much mass of O2 to produceAl2O3
a. 8g of oxygen
b. 16g of oxygen
c.32g of oxygen
d.24g of oxygen
(vi) The number of moles of co2 which contain 8.0 g of oxygen.
a. 0.25
b.0.50
c. 1.0
d.1.50
(vii) The largest number of molecules are present in
a. 3.6g of H2O
b. 4.8g of C2H5OH
c. 2.8 g of CO
d. 5.4g of N2O5
(viii) One mole of SO2 contains
a. 6.02×1023 atoms of oxygen
b. 18.1×10 23 Molecules of SO2
c. 6.02×1023 atoms of sulphur
d. 4 gram atoms of SO 2
(ix) The volume occupied by 1.4 g of N2 at STP is
a.2.24 dm3
b.22.4dm3
c.1.12 dm3
d.112 cm3
(x) A limiting reactant is the one which
a. is taken in lesser quantity in grams as compared to other reactants
b. is taken in lesser quantity in volume as compared to the other reactants
c. give the maximum amount of the product which is required
d. give the minimum amount of the product under consideration
Ans: (i)a
(ii)d
(iii)d
(iv)b
(v)d
(vi)a
(vii)a
(viii)c
(ix)c
(x)d
Fill in the blanks.
(i) The unit of relative atomic mass is———–
(ii) The exact masses of isotopes can be determined by ————spectrograph.
(iii) The phenomenon of isotopes was first discovered by ————–
(iv) Empirical formula can be determined by combustion analysis for thosecompounds which have———–and ———–in them.
(v) A limiting reagent is that which controls the quantities of ————-
(vi) I mole of glucose has———–atoms of carbon —————of oxygenand ———-of hydrogen.
(vii) 4g of CH4 at OoC and I atm pressure has ———molecules of CH4.
(viii) Stoichiometry calculations can by performed only when ————-law isobeyed.
Ans: (i) amu
(ii) mass
(iii) Soddy
(iv) carbon, hydrogen
(v) Products
(vi) 6NA,6NA,12NA
(vii) 1.505×1023
(viii) conservation and multipleproportion