# Chemical Formula & Equation

Mind Map by MIRA FAREENA, updated more than 1 year ago More Less
 Created by Sharifah Huda over 5 years ago Copied by Chee Mun Chan over 5 years ago Copied by hakiim kamarudin over 5 years ago Copied by Sharifah Huda over 5 years ago Copied by MIRA FAREENA over 5 years ago
9
0

### Description

Mind Map on Chemical Formula & Equation, created by MIRA FAREENA on 07/25/2016.

## Resource summary

Chemical Formula & Equation
1. Chemical Reaction
1. Number of atoms in 12g of carbon-12 atom
1. 6.002x10^23
2. Moles
1. Number of atoms and molecules
1. Number of moles(mol)=mass(g)/molar mass(g mol^-1)

Annotations:

• Number of moles(mol)=mass(g)/molar mass(g mol^-1)
2. Molar Volume
1. Standard temperature and volume:22.4L mol^-1
1. Volume occupied by 1 mol of gas
2. Chemical formulaes
1. Molecular formula
1. Chemical formula which shows the actual number of atoms in an element
1. n(empirical formula)
2. Empirical formula
1. Chemical formula which shows the simplest ratio of atoms of an element
1. Steps
1. 1)Determine the mass or percentage(by 100g) of elements in the compound

Annotations:

• 1)Determine the mass or percentage(by 100 g) of elements in the compound 2)Divide the mass/percentage of elements with respective relative atomic mass 3)Divide by the smallest number to obtain the ratio 4)Write the empirical formula from the ratio of the elements
1. 2)Divide the mass or percentage of elements with the respective relative atomic mass
1. 3)Divide with the smallest number to obtain the ratio
1. 4)Write the empirical formula from the ratio of the elements
2. Concentration of Solutions
1. A solution is a homogenous mixture of two or more substances
1. solvent + solute(s)
2. Expression
1. Mole Fraction (X)
1. Xa = moles of a / sum of moles of all components
2. Percentage by mass and volume
1. %w/w = (Mass of X / Mass of sample) x100%
1. %w/V = (mass of X (g) / Volume) x100%
1. %v/v = (Volume of X / Volume of Sample) x100%
2. Molality
1. Molality,m = moles of solute (mol) / mass of solvent (kg)
2. Molarity
1. Molarity = moles of solute / liters of solution
1. Units
1. mol L^-1
1. mol dm^-3
1. M
2. Dilution
1. procedure for preparing a less concentrated solution from a more concentrated solution
1. M1V1 = M2V2
2. neutralization reaction
1. acid + base ---> salt + water
2. Oxidation Number
1. Number that is assigned to an atom in a substance
1. Indicates if electron are lose or gain
1. Positive
1. Atom loses electron
1. eg. Ca2+ , atom lose 2 electron
2. Zero
1. Atoms neither gains nor lose electrons
2. Negative
1. Atoms gain electron
1. eg. O2- , atom gain 2 electrons
2. Rules
1. Pure Elemental Form
1. Atom that is not combined with other element
1. Oxidation Number = 0
1. eg : Ag, He, Cu
2. Ions
1. Atom with charge due to the gain or lose of electrons
1. Oxidation Number = charge for ions
1. eg: H+ oxidation number = +1
2. Neutral Compound
1. Sum of oxidation number = 0
1. eg. HCl, NaOH
2. Hydrogen
1. 2 Possible oxidation number
1. +1
1. -1
2. +1
1. Bonded to non-metal
1. eg: HCl - H+
2. -1
1. Bonded to metal
1. eg: NaH - H-
3. Calculation
1. Calculate the oxidation number of the element in neutral compound
1. eg. Hydrogen Fluoride
1. H = +1 F = ?
1. -1 + F = 0
1. F = -1
1. Therefore, the oxidation number of fluorine is -1
2. Limiting Reagent
1. Reaction
1. The reaction that stops once the limiting reagent is gone ( no matter how much the excess is present)
2. Limiting Reagent
1. Substance that are totally consumed when the chemical reaction is complete
2. Excess Reagent
1. The reactant presents in quantities greater than necessary to react with the quantity of the limiting reagent
2. Percentage Yield %
1. Theoretical yield
1. The amount of product that would result if all the limiting reagent reacted
2. Actual yield
1. The amount of product actually obtained from reaction
2. % yield
1. Actual Yield / Theoretical Yield x 100

### Similar

Social Influence
Work, Energy & Power: Quiz
Health and Social Care
3. The Bolshevik's Seizure of Power
Ionic Bonding
FCE Practice Fill In The Blank
FCE Practice Quiz - B2
GCSE AQA Biology 1 Cloning & Genetic Engineering
The Lymphatic System
Groups Starter Pack
FCE Practice Quiz - B2