Chemistry can be a challenging subject for many students, but with the right hacks, it can become a lot easier and even fun. In this blog post, we will share 100+ chemistry hacks that will help you understand and remember important concepts. We will also provide equational examples of each trick to demonstrate their practical application.
1. Mnemonic Devices
Use mnemonic devices to remember complex formulas and equations. Examples:
1. Roy G. Biv
To remember the colors of the visible light spectrum in order, use the popular mnemonic ‘Roy G. Biv,’ which stands for red, orange, yellow, green, blue, indigo, and violet. This helps you remember the sequence of colors in a rainbow.
2. H2O – Water
One of the most well-known chemistry mnemonics is ‘H2O,‘ which represents water. The ‘H’ stands for hydrogen, and the ‘O’ stands for oxygen. This simple mnemonic helps you remember the chemical formula for water.
3. Please Excuse My Dear Aunt Sally
‘Please Excuse My Dear Aunt Sally’ is a popular mnemonic used in mathematics, but it can also be applied to chemistry. It helps you remember the order of operations in chemical equations: Parentheses, Exponents, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right).
4. Never Trust a Skinny Cook
This mnemonic is useful for remembering the solubility rules in chemistry. ‘Never Trust a Skinny Cook’ stands for Nitrate, Thiosulfate, Acetate, Sulfate, Chloride, and Carbonate. It helps you remember the order of these ions and their solubilities.
5. OIL RIG
‘OIL RIG’ is a mnemonic used to remember the difference between oxidation and reduction reactions. ‘OIL’ stands for Oxidation Is Loss (of electrons), and ‘RIG’ stands for Reduction Is Gain (of electrons).
6. LEO the Lion says GER
This mnemonic helps you remember the electrolysis of water. ‘LEO’ stands for Loss of Electrons is Oxidation, and ‘GER’ stands for Gain of Electrons is Reduction. This helps you understand which electrode (anode or cathode) undergoes oxidation or reduction.
7. King Henry Died By Drinking Chocolate Milk
This mnemonic is used to remember the metric system prefixes. It stands for Kilo, Hecto, Deca, Base Unit, Deci, Centi, and Milli. It helps you remember the order of these prefixes and their corresponding values.
8. ‘Some Lovers Try Positions That They Can’t Handle’
This mnemonic helps you remember the trigonometric functions: Sine, Cosine, Tangent, Secant, Cosecant, and Cotangent. The first letter of each word corresponds to a trigonometric function, making it easier to recall them.
9. ‘I Ate Ten Eggs At Twelve’
This mnemonic helps you remember the order of the taxonomic ranks in biology: Kingdom, Phylum, Class, Order, Family, Genus, and Species. Each word corresponds to a taxonomic rank, making it easier to remember their order.
10. ‘Big Elephants Can Always Understand Small Elephants’
This mnemonic helps you remember the electromagnetic spectrum in order of increasing frequency: Radio, Microwaves, Infrared, Visible, Ultraviolet, X-rays, and Gamma rays. Each word corresponds to a type of electromagnetic wave.
2. Dimensional Analysis
Use dimensional analysis to convert between different units. Examples:
1. Converting between Celsius and Fahrenheit
The formula to convert Celsius to Fahrenheit is: F = (9/5)C + 32. Let’s say we have a temperature of 25 degrees Celsius and we want to convert it to Fahrenheit. Using dimensional analysis, we can set up the following equation:
25°C * (9/5) + 32 = 77°F
2. Converting between liters and milliliters
The conversion factor between liters and milliliters is: 1 L = 1000 mL. If we have a volume of 500 mL and we want to convert it to liters, we can use the following dimensional analysis:
500 mL * (1 L / 1000 mL) = 0.5 L
3. Calculating molar mass
To calculate the molar mass of a compound, we can use the formula: Molar mass = mass / moles. For example, if we have 10 grams of sodium chloride (NaCl) and we want to find the molar mass, we can use dimensional analysis:
10 g NaCl * (1 mol NaCl / 58.44 g NaCl) = 0.171 mol NaCl
4. Determining concentration
The formula to calculate concentration is: Concentration = moles / volume. Let’s say we have 0.5 moles of a solute dissolved in 2 liters of solution. We can calculate the concentration using dimensional analysis:
0.5 mol / 2 L = 0.25 M
5. Converting between grams and moles
The formula to convert grams to moles is: Moles = mass / molar mass. If we have 25 grams of water (H2O) and we want to find the number of moles, we can use dimensional analysis:
25 g H2O * (1 mol H2O / 18.015 g H2O) = 1.388 mol H2O
6. Finding percent composition
The formula for percent composition is: Percent composition = (mass of element / molar mass of compound) * 100. Let’s say we want to find the percent composition of oxygen in carbon dioxide (CO2). We can use dimensional analysis:
(32 g O / 44.01 g CO2) * 100 = 72.70%
7. Calculating empirical formula
To calculate the empirical formula of a compound, we need the percent composition of each element. The formula is: Empirical formula = (percent composition / molar mass) * 100. For example, if we have a compound with 40% carbon and 60% oxygen, we can use dimensional analysis:
(40 / 12.01) * 100 = 333.05
8. Balancing chemical equations
Dimensional analysis can also be used to balance chemical equations. By making sure that the number of atoms of each element is the same on both sides of the equation, we can achieve a balanced equation. For example, let’s balance the equation for the combustion of methane (CH4):
CH4 + 2O2 → CO2 + 2H2O
9. Calculating reaction yield
To calculate the reaction yield, we can use dimensional analysis. The formula is: Reaction yield = (actual yield / theoretical yield) * 100. Let’s say we have a reaction that produces 50 grams of a product, but the theoretical yield is 60 grams. We can calculate the reaction yield using dimensional analysis:
(50 g / 60 g) * 100 = 83.33%
10. Converting between different units of pressure
There are several dimensional analysis formulas to convert between different units of pressure, such as atmospheres (atm), pascals (Pa), and millimeters of mercury (mmHg). For example, to convert 1 atm to mmHg, we can use the following formula:
1 atm * (760 mmHg / 1 atm) = 760 mmHg
These are just a few examples of the many dimensional analysis formulas used in chemistry. By understanding and applying these formulas, we can perform accurate calculations and solve complex problems in the field of chemistry.
3. Titration Tricks
When performing a titration, add a few drops of phenolphthalein indicator to the solution to get a clear color change at the endpoint.
4. Balancing Equations
Balance chemical equations by adjusting coefficients. For example, in the equation 2H2 + O2 -> 2H2O, you need two molecules of H2 and one molecule of O2 to produce two molecules of H2O.
5. Solubility Rules
Memorize solubility rules to determine whether a compound will dissolve in water or not.
To make the memorization process easier and more efficient, here are five effective hacks:
- Create Mnemonic Devices: Mnemonic devices are memory aids that help you remember information through associations. For example, to remember that all nitrates are soluble, you can create a phrase like ‘Nitrates Never Sink’.
- Visualize the Reactions: Visualizing the reactions can help you understand and remember the solubility rules. Create mental images of the compounds dissolving or precipitating and associate them with the corresponding rules.
- Practice with Flashcards: Flashcards are a great tool for memorization. Write the compounds on one side and their solubility on the other. Test yourself frequently to reinforce your knowledge.
- Use Online Resources: There are plenty of online resources available that provide interactive quizzes and games to help you memorize the solubility rules. Take advantage of these resources to make studying more engaging.
- Apply the Rules: The best way to solidify your understanding of solubility rules is to apply them in practice. Perform experiments and observe the outcomes to see the rules in action.
For example, most salts containing nitrate (NO3-) and ammonium (NH4+) ions are soluble in water.
6. Stoichiometry Shortcuts
Use stoichiometry shortcuts to calculate the amount of product formed in a chemical reaction. Examples:
1. Convert Grams to Moles:
One of the most common tricks is to convert grams to moles using the molar mass of the substance. For example, if you have 10 grams of hydrogen gas (H2), you can convert it to moles by dividing the mass by the molar mass (2 grams/mole). This trick allows you to work with moles, which is often more convenient in stoichiometry equations.
2. Use Mole Ratios:
Mole ratios are essential in stoichiometry equations. They allow you to convert between different substances in the equation. For instance, if you have 2 moles of hydrogen gas and want to find the number of moles of water produced, you can use the mole ratio from the balanced equation (2 moles of hydrogen gas produce 1 mole of water).
3. Balance the Equation:
A balanced equation is crucial for stoichiometry calculations. Balancing the equation ensures that the number of atoms on both sides of the equation is equal. This allows you to use the mole ratios accurately. For example, if you have an unbalanced equation like H2 + O2 → H2O, you need to balance it to 2H2 + O2 → 2H2O.
4. Limiting Reactant:
The limiting reactant is the substance that is completely consumed in a reaction. To find the limiting reactant, you can use stoichiometry calculations. For instance, if you have 10 moles of hydrogen gas and 5 moles of oxygen gas, you can determine the limiting reactant by comparing the mole ratios from the balanced equation.
5. Excess Reactant:
The excess reactant is the substance that is left over after the reaction is complete. To find the excess reactant, you can subtract the amount of the limiting reactant from the total amount of the reactant used. This trick allows you to determine the amount of reactant that is not consumed in the reaction.
6. Use Stoichiometry Tables:
Stoichiometry tables are a great tool to organize the information in a stoichiometry problem. They help you keep track of the substances, their moles, and their masses. By using a stoichiometry table, you can easily solve complex stoichiometry problems step by step.
7. Convert Moles to Grams:
Similar to converting grams to moles, you can also convert moles to grams using the molar mass of the substance. This trick is helpful when you need to find the mass of a substance in a stoichiometry equation. For example, if you have 5 moles of water, you can convert it to grams by multiplying the moles by the molar mass of water (18 grams/mole).
8. Use the Ideal Gas Law:
If you are dealing with gases in your stoichiometry equation, you can use the ideal gas law (PV = nRT) to solve for various variables. This equation relates the pressure, volume, number of moles, and temperature of a gas. By rearranging the equation, you can solve for the desired variable.
9. Convert Volume to Moles:
If you have the volume of a gas and need to convert it to moles, you can use the ideal gas law. Assuming the pressure, temperature, and number of moles are constant, you can rearrange the equation to solve for moles. This trick is particularly useful when dealing with gases in stoichiometry equations.
10. Use Stoichiometry Coefficients:
The stoichiometry coefficients in a balanced equation tell you the mole ratio between the different substances. By using these coefficients, you can convert between moles of different substances.
For example, if you have 3 moles of hydrogen gas and want to find the number of moles of oxygen gas needed, you can use the stoichiometry coefficient (2 moles of hydrogen gas react with 1 mole of oxygen gas).
7. Gas Laws
Gas laws are fundamental principles that describe the behavior of gases under different conditions. While the equations may seem intimidating, there are several tricks that can help you easily understand and apply them.
1. Boyle’s Law Trick: The product of pressure and volume is constant at constant temperature. P1V1 = P2V2. For example, if the pressure is doubled, the volume is halved.
2. Charles’s Law Trick: The volume of a gas is directly proportional to its temperature at constant pressure. V1/T1 = V2/T2. For instance, if the temperature is doubled, the volume also doubles.
3. Gay-Lussac’s Law Trick: The pressure of a gas is directly proportional to its temperature at constant volume. P1/T1 = P2/T2. If the temperature is doubled, the pressure also doubles.
4. Avogadro’s Law Trick: The volume of a gas is directly proportional to the number of moles at constant temperature and pressure. V1/n1 = V2/n2. If the number of moles is doubled, the volume also doubles.
5. Combined Gas Law Trick: Combines Boyle’s, Charles’s, and Gay-Lussac’s laws into one equation: P1V1/T1 = P2V2/T2. It allows you to calculate changes in pressure, volume, and temperature simultaneously.
6. Ideal Gas Law Trick: Combines all the gas laws into one equation: PV = nRT. It relates pressure, volume, temperature, and the number of moles of a gas.
7. Dalton’s Law Trick: The total pressure of a mixture of gases is equal to the sum of the partial pressures of each gas. Ptotal = P1 + P2 + P3 + …
8. Graham’s Law Trick: The rate of effusion or diffusion of a gas is inversely proportional to the square root of its molar mass. r1/r2 = √(M2/M1).
9. Henry’s Law Trick: The solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. C = kP, where C is the concentration of the gas and P is its partial pressure.
10. Van der Waals Equation Trick: Corrects for the behavior of real gases by introducing two additional terms: (P + an^2/V^2)(V – nb) = nRT. It accounts for the attractive forces between gas molecules and the volume occupied by the molecules.
Understanding these gas law equation tricks can greatly simplify your understanding of gas behavior. With practice, you’ll be able to solve gas law problems with confidence and ease.
8. Acid-Base Reactions
Learn the properties of acids and bases to identify and predict acid-base reactions. Examples:
1. Balancing Equations
When balancing acid-base reaction equations, always start by balancing the atoms other than hydrogen and oxygen. Then, balance hydrogen by adding H+ ions and oxygen by adding H2O molecules.
Consider the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH):
HCl + NaOH → NaCl + H2O
By following the balancing equation trick, we can balance the equation as follows:
HCl + NaOH → NaCl + H2O
2HCl + 2NaOH → 2NaCl + 2H2O
2. Neutralization Reactions
In neutralization reactions, an acid reacts with a base to form a salt and water. The general equation for neutralization reactions is:
Acid + Base → Salt + Water
Let’s consider the reaction between hydrochloric acid (HCl) and sodium hydroxide (NaOH) again:
HCl + NaOH → NaCl + H2O
3. Displacement Reactions
In displacement reactions, a more reactive acid displaces a less reactive acid from its compound. The general equation for displacement reactions is:
Reactive Acid + Compound with Less Reactive Acid → Reactive Acid Compound + Less Reactive Acid
Hydrochloric acid (HCl) can displace acetic acid (CH3COOH) from sodium acetate (CH3COONa):
HCl + CH3COONa → CH3COOH + NaCl
4. Gas Formation Reactions
Some acid-base reactions result in the formation of gases. The general equation for gas formation reactions is:
Acid + Base → Salt + Water + Gas
When hydrochloric acid (HCl) reacts with calcium carbonate (CaCO3), carbon dioxide (CO2) gas is formed:
HCl + CaCO3 → CaCl2 + H2O + CO2
5. Redox Reactions
Redox reactions involve the transfer of electrons between the acid and the base. The general equation for redox reactions is:
Acid (Reducing Agent) + Base (Oxidizing Agent) → Salt + Water
When sulfuric acid (H2SO4) reacts with potassium permanganate (KMnO4), manganese dioxide (MnO2) and water (H2O) are formed:
H2SO4 + KMnO4 → MnO2 + K2SO4 + H2O
9. Redox Reactions
Understand oxidation and reduction reactions to balance redox equations. For example, in the reaction 2Fe2O3 + 3C -> 4Fe + 3CO2, iron (Fe) is reduced while carbon (C) is oxidized.
Check this out this way:
1. Half-Reaction Method
A useful trick for balancing redox equations is to split the reaction into two half-reactions, one for oxidation and one for reduction. Balance the atoms and charges in each half-reaction separately, and then combine them to form the balanced redox equation.
Let’s consider the reaction between potassium permanganate (KMnO4) and hydrogen peroxide (H2O2) in an acidic solution:
Half-Reaction 1 (Oxidation): 5e– + 8H+ + MnO4– → Mn2+ + 4H2O
Half-Reaction 2 (Reduction): H2O2 → 2H+ + 2e–
By balancing the atoms and charges in each half-reaction, we can combine them to obtain the balanced redox equation:
2KMnO4 + 3H2O2 + 6H+ → 2Mn2+ + 5O2 + 2K+ + 8H2O
2. Oxidation Number Method
Another approach is to assign oxidation numbers to each element in the reactants and products. The change in oxidation state indicates the number of electrons transferred.
Ensure that the total increase in oxidation numbers equals the total decrease in oxidation numbers to balance the redox equation.
Consider the reaction between sodium sulfite (Na2SO3) and chlorine gas (Cl2):
Oxidation Number Method:
Na2SO3 + Cl2 → Na2SO4 + 2NaCl
By assigning oxidation numbers and balancing the changes in oxidation state, we can obtain the balanced redox equation:
2Na2SO3 + 3Cl2 → Na2SO4 + 6NaCl
3. Balancing by Stoichiometry
One trick is to use stoichiometry to balance redox equations. By adjusting the coefficients of the reactants and products, you can ensure that the number of atoms on both sides of the equation is equal.
Let’s consider the reaction between potassium permanganate (KMnO4) and iron(II) sulfate (FeSO4) in an acidic solution:
KMnO4 + FeSO4 → K2SO4 + MnSO4 + Fe2(SO4)3
By adjusting the coefficients, we can obtain the balanced redox equation:
2KMnO4 + 10FeSO4 + 8H2SO4 → K2SO4 + 2MnSO4 + 5Fe2(SO4)3 + 8H2O
10. Periodic Table Tricks
Use the periodic table to find information about elements, such as atomic number, atomic mass, and electron configuration.
1. Element Symbol Spelling
Did you know that you can spell words using the symbols of elements from the periodic table? For example, the symbols for sulfur (S), hydrogen (H), iodine (I), and technetium (Tc) can be rearranged to spell ‘this.’ You can challenge your friends to come up with words and see who can find the most!
2. Atomic Number Math
The atomic numbers of elements on the periodic table can be used for simple math tricks. For example, if you add the atomic numbers of carbon (6), oxygen (8), and nitrogen (7), the sum is 21, which is also the atomic number of scandium. You can create your own math puzzles using the atomic numbers of different elements.
3. Element Colors
Each element on the periodic table has a unique color. You can use this information to create colorful patterns or designs. For example, you can arrange the elements in a rainbow-like order based on their colors. This can be a great way to learn about the different elements and their properties.
11. Lewis Structures
Draw Lewis structures to visualize the bonding and electron distribution in molecules. For example, the Lewis structure of water (H2O) shows that oxygen (O) has two lone pairs of electrons and two bonds.
12. Acid-Base Titrations
When performing an acid-base titration, use a pH meter or pH indicator paper to determine the equivalence point.
Understand the principles of electrochemistry, such as oxidation-reduction reactions and electrochemical cells, to explain the behavior of chemical reactions involving electricity.
14. Organic Chemistry
Learn the basics of organic chemistry, such as the structure and properties of organic compounds, to understand the chemistry of carbon-based compounds.
Use spectroscopy techniques, such as infrared spectroscopy and nuclear magnetic resonance spectroscopy, to analyze the structure and composition of compounds.
Understand the laws of thermodynamics, such as the first law and second law, to predict the direction and extent of chemical reactions.
17. Equilibrium Constants
Use equilibrium constants to determine the direction and extent of chemical reactions at equilibrium. For example, a larger equilibrium constant (Kc) indicates a higher concentration of products compared to reactants.
18. Lab Safety
Follow proper lab safety procedures to ensure your safety and the accuracy of your experiments.
19. Periodic Trends
Understand periodic trends, such as atomic radius and electronegativity, to predict the properties of elements and their compounds.
20. Practice, Practice, Practice
The most important hack of all is to practice regularly. Solve chemistry problems, do practice exams, and review your notes to reinforce your understanding of the subject.
By using these 20 chemistry hacks, you can improve your understanding of chemistry and excel in your studies. Remember to practice regularly and seek help when needed. Chemistry can be challenging, but with the right strategies, you can overcome any obstacle.