How to calculate Molar mass and names practice questions

Calculate molar mass of the following compounds and formula units and write their names.

1.       Na2O

2.        H2O

3.        NaOH

4.        MgO

5.        Mg(OH)2

6.       Li2O

7.        HCl

8.       LiCl

9.       MgCl2

10.   P4O10

11.   H3PO4

12.   Cl2O7

13.   HClO4

14.   SO2

15.   H2SO3

16.   SiO2

17.   OH−

18.   SiO32−

19.   Al2O3

20.   H2SO4

21.   Al2(SO4)3

22.   Al (OH)4−

23.   CO

24.   NO

25.    CO2

26.    N2

27.   𝐶𝐻4

28.   𝑂2

29.   𝐶6𝐻12𝑂6

30.   𝑆𝑂𝐶𝑙2

31.    𝐹𝑒𝐶𝑙3.

How to prepare for the IB and IGCSE examinations?

How to prepare for the IB and IGCSE examinations?

Examination management plan:

It is not too late to start preparation for coming IB and IGCSE exams. What has happened in past is not a point of thought for now. It is time to gather all your energy and plan for writing exams.

You can focus on following steps to see yourself in a better place during exams:

1. Choose relevant and selective study material like IB and IGCSE textbook, notes, guide books etc.

2. Believe in yourself that you can do it.

3. Make a time table to study all subjects according to your need.

4. Do not focus on one subject only but study all subjects on scheduled time.

5. Make some small points for quick revision. You may prepare flash cards also.

6. Check the IB and IGCSE syllabus of your exam and identify the simpler topics first to study.

7. After covering simple topics you will gain confidence, now start solving past papers and solve only the questions from topics you already covered.

8. Now select one hard topic and divide it in small parts to study one by one. Continue the work till the exams starts.

9. Take healthy diet and keep positive attitude.

10. Do not visit the friends who de motivate you.

During Exam day:

1. Wake up on time and get ready for exam.

2. Do not panic and remain relaxed.

3. Check all necessary stationary like pen, pencil etc

4. Reach the exam room on time and drink water before exam because without water due to dehydration you may get head ach.

5. Read the compulsory instructions given on the question paper and start answering the known questions or easy questions than hard questions.

6. Do not waste too much time on thinking the answer but after finishing the questions you may again work on the unsolved questions.

7. Once you finish the question paper, check the answer sheet once again.

8. Ensure that you have filled all necessary information on answer sheet.

9. After the exam, do not compare the answers with anyone because it will affect your next exam.

10. Start planning and preparing for next exam.

Definition of Mole and it’s relationship with mass

 Definition of Mole and it’s relationship with mass

 It is an amount of a substance which contains as many particles as there are in

12 g of C-12 isotopes that is  6.022X10²³

6.022X10²³ is known as Avogadro's number.

For example: 1 mole atoms = gram atomic mass = 6.022X10²³ atoms

                 
 1 mole oxygen atoms = gram atomic mass of oxygen =16 g = 6.022X10²³ atoms

1 mole molecules  = gram molecular  mass = 6.022X10²³  molecules

Example -

1 mole oxygen  molecules  = gram molecular  mass of oxygen =32 g =

6.022X10²³ oxygen molecules

1 mole ions  = formula unit mass = 6.022X10²³ ions

Example - 1 mole( SO₄)^2- ions  = formula unit mass of ( SO₄)^2-=96g = 6.022X10²³
  ( SO₄)²ions

The mass (nucleon) number, A, is the sum of the protons and the neutrons. (= 12 for Carbon)

The atomic (proton) number, Z, of an element is the number of protons in the nucleus of the atom. In the neutral atom it is equal to the number of electrons. ( 6 for Carbon)

The Relative Atomic Mass, A(r), is the mass of one atom of an element compared to a scale in which one atom of carbon-12 has a mass of 12.0000.

The Relative Molecular Mass, M(r), is the ratio of the mass of one molecule of a substance to the mass of one atom of carbon-12. It is calculated by adding the relative atomic masses of all the atoms of all elements in the molecule.

Relative molecular mass, M(r), or  relative formula mass (for those compounds that do not exist as molecules) is calculated by adding together the Relative Atomic MassA(r) ‘s of the elements in the molecular formula.

Use of State symbols in Chemical Equations

Use of State symbols in Chemical Equations

Use of state symbols is very key to get marks in IB diploma exams. It is not difficult to use state symbols in chemical equations.
What is state symbols? 
State symbols are symbols used to represent the physical state of reactants and products in a chemical equation.

Example:

White solid magnesium Oxide is formed when Magnesium metal ribbon is burned in air( oxygen gas).

2Mg(s) + O2(g)    à 2 MgO(S) 

Try to write the state symbols of the following equations:

Ag⁺   + X⁻   → AgX(s)

Na₂O + H₂O → 2NaOH

 MgO + H₂O → Mg(OH)₂

Li₂O(s) + 2HCl → 2LiCl  + H₂O

MgO + 2HCl  → MgCl₂ + H₂O

P₄O₁₀+ 6 H₂O→ 4H₃PO₄

Important Chemical equations for IB Chemistry Final exams

These are the important chemical equations carefully selected from entire  IB chemistry course.
Try to practice by balancing these equations.

Ag⁺(aq) + X⁻(aq) → AgX(s)

Na₂O(s) + H₂O(l) → NaOH(aq) 

MgO(s) + H₂O(l) → Mg(OH)₂

O²⁻(s) + 2H⁺(aq) → H₂O(l)

Li₂O(s) + HCl(aq) → LiCl (aq) + H₂O(l)

MgO(s) + HCl (aq) → MgCl₂(aq) + H₂O(l)

P₄O₁₀(s) +  H₂O(l)→ H₃PO₄(aq)

Cl₂O₇(l) + H₂O(l)→ HClO₄(aq)

SO₂(g) + H₂O(l)→ H₂SO₃(aq)

SiO₂(s) + 2OH−(aq) → SiO₃²⁻⁽aq) + H₂O(l)

Al₂O₃(s) + H⁺ → Al⁺³(aq) +  H₂O(l)

Al₂O₃(s)  + H₂SO₄(aq) → Al₂(SO₄)₃(aq) + H₂O(l)

Al₂O₃(s) + H₂O(l)+ OH⁻(aq) → Al(OH)⁴⁻ (aq)

CO(g) + NO(g) → CO₂ (g) + N₂(g)

𝐶𝐻₄ (𝑔) + 𝑂₂ (𝑔) → 𝐶𝑂₂ (𝑔) + 𝐻₂(𝑙)

𝐶𝑂₂ (𝑔) + 𝐻₂(𝑙) → 𝐶₆𝐻₁₂𝑂₆ (𝑎𝑞) + 𝑂₂ (𝑔)

𝑆𝑂𝐶𝑙₂ (𝑙) + 𝐹𝑒𝐶𝑙_3.  +   𝐻₂(𝑠) → 𝐹𝑒𝐶𝑙₃ (𝑠) + 𝑆𝑂₂ (𝑔) + 𝐻𝐶𝑙(𝑔)

Particulate nature of matter

Particulate nature of matter

1.1 Introduction to the particulate nature of matter and chemical change
Matter : Anything which occupy space and has a mass is called matter.
Example: Air, Water, Oil, wood , Iron etc

Types of matter:

matter is basically of three types:

Solid: Particles are held very close to each other in solids in a regular order and there is very little freedom of movement due to strong attractive forces between particles.

 As a result, Solids have definite volume and definite shape.

 Question: Write few  examples of solids.

Challenge: Is Clay solid or liquid? Why is it solid or liquid?

Liquid: Particles are close to each other but they can move around due to weaker attractive forces 

 between particles compared to solid particles.

              As a result, Liquids have definite volume but do not have definite shape. 

They acquire the shape of the container in which they are kept.

Question: Name 5 liquids. Is toothpaste a liquid?

Gas : Particles are far apart their movement is easy and fast due to negligible attractive forces between particles. Gases have neither definite volume nor definite shape. They completely occupy the space in the container in which they are placed.

Question: Name 5 gases. 

Challenge: Is gas or vapour same?

 Why  or why not?

nter-conversion of States of matter:

The states of matter are inter-convertible by changing the conditions of temperature and pressure. 

On heating, a solid usually changes to a liquid, and the liquid on further heating changes to gas or vapour. 

In the reverse process, a gas on cooling liquifies to a liquid and the liquid on further cooling freezes to the solid.

Puzzle on Alkali Metals

This puzzle can be used as a fun learning activity on Alkali Metals. Teachers can use it as a starter or gap-filling activity or as an evaluation tool for Chemistry vocabulary building. This helps in improving litracy skills in chemistry.

Task: Find alkali metals in the following puzzle.

A S L I M C J T U C X S M M P 

D O J Q R U A I T Y T I U B F 

Q D Y V M O I E J C C R I G Z 

H I T L L T V S S S H T D R Z 

J U D X J F Y V S I D S I Z C 

E M F Z D K Q M I A U T B E Q 

T A Y S Z O Z Y I M T M U M P 

B D S X L P A K U X I O R H F 

V X E F A V X I Q M Q G P S Z 

H C U Y T U C R U D C W I J D 

Q K E Y W N Y C W J C Z J J S 

Q H H A A O A V R H C B U R C 

D O L R Q Z W J U G G A O Q C 

P V F L E C H H G P Y B A F N 

I K M K U A L I T H I U M C R