Heat and Temperature

What is Heat?

The exchange of energy due to difference in temperature is called heat. But as a noun we can say that the Heat is the quality of being hot or high temperature and to understand easily we can say that feeling of hot or warm is heat.

Heat

The exchange of energy due to difference in temperature is called heat. We may also explain as, heat is the form of the energy that is moved between two substances at different temperatures. Means if two substances are in contact and one has 200K temperature and other have 100K temperature then the direction of energy flow is from the substance at the higher temperature to the substance of lower temperature. Means in above case heat flows from substance having 200k temperature to substance having 100K temperature.

Heat is a form of energy so heat is measured in units of energy, commonly calories or joules.

What is Temperature?

Temperature is the quantity of hotness or coldness of any substance. Simply we can say that Temperature is the measurement of how much an object is hot or cold.

Temperature

Temperature is the quantity of hotness or coldness. Also in scientific way, temperature is explained as the average kinetic energy per molecule of a substance. Heat and Temperature (Temp, T) are two different terms and have different meanings so don’t get confuse between them.  Heat is energy while temperature is not energy. Heat is measured in Joules while temperature is measured in Celsius (C), Fahrenheit (F) or Kelvin (K). Symbol used for heat is Q while symbol used for temperature is T. SI unit of heat is Joule while SI unit of temperature is Kelvin.

Heat VS Temperature

Heat is the flow of energy from hot object to cold object while temperature is the measurement of how much an object is hot or cold. Heat is energy while temperature is not energy. Heat is measured in Joules while temperature is measured in Celsius (C), Fahrenheit (F) or Kelvin (K). Symbol used for heat is Q while symbol used for temperature is T. SI unit of heat is Joule while SI unit of temperature is Kelvin.

Structure of Atom Class 11 MCQ

Structure of Atom MCQ

These are some of the random multiple question answers from Structure of Atom... 

1. Who discovered anode rays :

 Goldstein
 Rutherford
 J. Stanley
 J. J. Thomson

2. Neutron was discovered by :

 Rutherford
 Chadwick
 Austin

 Langmuir

3. Radioactive isotope of hydrogen has ________ number of neutrons :

 0

 1

 2

 3

4. Cathode rays are deflected by :

 A magnetic field only
 An electric field only

 By Both
 By None

5. Cathode rays have :

 Mass Only
 Charge Only
 Mass and Charge Both
 No Charge and No Mass

6. Mass of atom is mainly constituted by :

 Neutrons and neutrino
 Neutrons and electrons

 Neutrons and protons
 Protons and electrons

7. Ratio of mass of proton and electron is :

 1.8
 1.8x10³

 Infinite
 None of these

8. Atomic number of an element is equal to the number of  :

 Proton

 Electron

 Neutron

 Electron and Proton

9. Size of nucleus is :

 10^-8 m

 10^-10 m

 10^-12 m

10^-15 m

10. Who modifies Bohr’s model :

 Dalton
 Pauli
 Rutherford
 Sommerfeld

Also read Chemistry Notes of this chapter at below link...
11 Class Chapter 2- Structure of Atom

Some Basic Concepts of Chemistry Class 11 MCQ

Some Basic Concepts of Chemistry Class 11 MCQ

These are some of the random multiple question answers from Some Basic Concept of Chemistry...

1. If a matter has definite volume and definite shape, then it is :

Solid
Liquid
Gas
All of the Above

2. Mole is SI unit of :

Current
Temperature
Amount of Substance

Luminous intensity

3. A measured temperature is 100 ⁰F on Fahrenheit scale, then what is this reading be on Celsius scale :

11.2 ⁰C

78 ⁰C

102.7 ⁰C

37.8 ⁰C

4. What amount of H­₂O produced by combustion of 32 g of CH₄ :

36 g
18 g
72 g
90 g

5. How many moles of CH₄ is needed to get 44 gram CO₂ after combustion :

0.5 mol of Methane
1 mol of Methane
2 mol of Methane
4 mol of Methane

6. Calculate the mass per cent of the solute, when a solution is prepared by adding 4 gram of substance A to 36 gram of water :

10%
20%
30%
40%

7. What is molarity of  NaOH in the Solution, that is prepared by adding 2 gram NaOH in water to get 500 mL of the solution :

0.4 M
1.0 M
0.1 M
4.0 M

8. A measured temperature is 44 ⁰C on Celsius scale, then what is this reading be on Fahrenheit scale :

111.2 ⁰F

88.8 ⁰F

32 ⁰F

199.8 ⁰F

9. Dalton in 1803, gives :

Law of conservation of mass

Law of definite proportion

Law of multiple proportion

Gay Lussac’s law of gaseous volume

10. The prefix 10^-15 is :

Atto
Femto
Peta
Tera

View below video on Some Basic Concept of Chemistry Quiz

Also read Chemistry Notes of this chapter at below link...

11 Class Chapter 1- Some Basic Concept of Chemistry Notes

Chemistry Formulas for Chemical Bonding

Chemistry Formulas for Chemical Bonding

 

   1.       Necessary condition for an ionic solid to be dissolved in water

                                Hydration Energy > Lattice Energy

   2.       Order of melting and boiling points of certain compounds

NaF > NaCl > NaBr > NaI;    MgO > CaO > BaO

3.       No Bond is 100% Ionic

4.       Force of attraction between two oppositely charged ions in vacuum (air) as per Coulombs Law

F = q₁q₂/r²

5.       Order of the Lattice Energy of some compounds

·         LiX > NaX > KX > RbX > CsX    (where X = F, Cl, Br, I)

·         MgO > CaO > SrO > BaO

·         MgCO₃ > CaCO₃ > SrCO₃ > BaCO₃

·         BaSO₄ > SrSO₄ > CaSO₄ > MgSO₄  

·         Mg(OH)₂ > Ca(OH)₂ > Sr(OH)₂ > Ba(OH)₂

·         Bivalent Ions-Bivalent Ions > Univalent Ions-Bivalent Ions or Bivalent Ions-Univalent Ions > Univalent Ions- Univalent Ions

6.       Example of some compounds which contains more than one type of bond

·         NaOH, KOH, Na₂CO₃  (Ionic Bond, Covalent Bond)

·         CO, NH₃.BF₃, [Co(NH₃)₃Cl₃]  (Dative Bond, Covalent Bond)

·         NH₄Cl, CuSO₄, K₄[Fe(CN)₆], [Cu(NH₃)₄]SO₄  (Dative Bond, Ionic Bond, Covalent Bond)

·         CuSO₄.5H₂O  (Hydrogen Bond, Dative Bond, Ionic Bond, Covalent Bond)

7.       Double bond or triple bond is always shorter than corresponding single bond

8.       As S-Orbital is smaller than P-Orbital so bond length decrease with increase in S-character

SP³  C-H  =  1.093 Å (as in Alkanes)

SP²  C-H  =  1.087 Å (as in Alkenes)

SP  C-H  =  1.057 Å (as in Alkynes)

9.       Bond length increases if size of bonded atom is increases with given atom

HI > HBr > HCl > HF

10.   Bond distance is directly proportional to Atomic size

11.   Order of bond strength (or bond energy) of different hydrogen halides

H-F > H-Cl > H-Br > H-I

12.   Bond energy is directly proportional to bond order

Triple Bond > Double Bond > Single Bond

13.   Formula of Dipole Moment

Dipole moment (µ) = Electronic Charge (e) x Distance (d)

14.   Unit of Dipole Moment

Debye (D)

1D = 1 x 10^-18e.s.u. cm

SI unit of Dipole Moment is = Coulomb-Meter (C-m)

1D = 3.336 x 10^-30 C-m

15.   Dipole Moment of some substances

Substance with Formula	Dipole Moment (D)
HF	1.91
H2O	1.84
SO2	1.60
NH3	1.46
NF3	0.24
CH3Cl	1.86
HCl	1.03
H2S	1.10
HBr	0.78
HI	0.38

16.   Formula to calculate percentage ionic character of covalent bond

% Ionic Character = (Observed dipole moment x 100)/Dipole moment for 100% ionic bond

17.   Order of polarizing power of cations

Li⁺ > Na⁺ > K⁺ > Rb⁺ > Cs⁺

Be²⁺ > Mg²⁺ > Ca²⁺ > Sr²⁺ > Ba²⁺

Al³⁺ > Mg²⁺ > Na⁺

18.   Order of polarizing power of anions

N^3- > O^2- > F^-

P^3- > S^2- > Cl^-

19.   Chemistry Formula of Bond Order

Bond Order = [N_b-N_a]/2

Where,

                N_a = Number of electrons in antibonding molecular orbitals

                N_b = Number of electrons in bonding molecular orbitals

20.   Some molecules with their bond order, bond length and bond dissociation energy

Molecule	Bond Order	Bond Length (pm)	Bond Dissociation Energy (kJ/mol)
F2	1	142	158
O2	2	121	498
N2	3	110	945

21.   Bond Order in compounds which exhibits Resonance

Bond Order = (Total No. of bonds between two atoms)/(Total No. of resonating structures)

Science Quiz : Acids and Bases Chemistry MCQs Part 18

Science Quiz : Acids and Bases Chemistry MCQs

Science Quiz by www.ChemistryNotesInfo.com

These are some of the random multiple question answers from Acids and Bases Chemistry...

1. OH^- ion is called as:

Hydronium Ion
Hydroxide Ion
Hydrate Ion
Hydrogen Ion

2. Taste of acidic food is:

Sweet
Salty
Sour
Bitter

3. H⁺ Ion (Hydrogen Ion) is simply a:

Proton
Neutron
Electron
Hydroxide Ion

4. Bases increases concentration of what in water:

H⁺ Ion
OH^- Ion
Both
None

5. Which of the acid from given below choice of acids is more dangerous:

Citric Acid
Carbonic Acid
Hydrochloric Acid
None of the above

6. Which of the given below statement about Alkalis is true:

They cannot neutralise acids
They are all insoluble
They are all acids
They are all bases

7. What happens to litmus paper in basic solutions:

Red litmus paper turns blue
Blue litmus paper turns red
Pink litmus paper turns Black
Black litmus paper turns blue

8. A liquid has a pH of 6.5, so this liquid is:

Weakly acidic
Weakly alkaline
Strongly acidic
Neutral

9. A liquid has a pH of 14, so this liquid is:

Weakly acidic
Weakly alkaline
Strongly acidic
Strongly basic

10. If a solution have pH of 9, then its H⁺ concentration is:

1 x 10^-9 moles/liter
1 x 10^-18 moles/liter
1 x 10⁹ moles/liter
1 x 10¹⁸ moles/liter