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Formula Sheet: Nature of Matter: Elements, Compounds, and Mixtures

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Nature of Matter: Elements, Compounds, and Mixtures – Formula & Equation Sheet

Essential formulas and equations from Curiosity, tailored for Class 8 in Science.

This one-pager compiles key formulas and equations from the Nature of Matter: Elements, Compounds, and Mixtures chapter of Curiosity. Ideal for exam prep, quick reference, and solving time-bound numerical problems accurately.

Formula and Equation Sheet

Formula sheet

Key concepts & formulas

Essential formulas, key terms, and important concepts for quick reference and revision.

Formulas

1

M = m_1 + m_2

M is the total mass of a mixture, m_1 and m_2 are the masses of individual components. This formula shows how the mass of a mixture is the sum of the masses of its parts.

2

C = (mass of solute)/(mass of solution) × 100%

C represents the concentration of a solution. A higher concentration means more solute is present in the mixture. Useful in chemistry labs for solution preparation.

3

d = m/V

d is density, m is mass, and V is volume. Density helps determine whether a substance will float or sink when mixed with another.

4

P_total = P_1 + P_2 + ... + P_n

P_total is the total pressure of a gas mixture, and P_1, P_2 are the partial pressures of individual gases. Used for calculations involving air and other gas mixtures.

5

PV = nRT

This is the ideal gas law where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature. It describes the behavior of ideal gases.

6

NaCl (s) → Na⁺ (aq) + Cl⁻ (aq)

The dissociation of sodium chloride in water. Shows how ionic compounds break into ions in mixtures, which is crucial for understanding solutions.

7

Lime Water Reaction: Ca(OH)₂ + CO₂ → CaCO₃ (s) + H₂O

This equation demonstrates how lime water reacts with carbon dioxide to form calcium carbonate. Important in experiments dealing with gases.

8

P_comb = (1/P₁ + 1/P₂ + ... + 1/P_n)⁻¹

This is for calculating the combined resistance in parallel circuits, used in physics to understand mixtures of resistive materials.

9

T_mixture = (m₁T₁ + m₂T₂)/(m₁ + m₂)

T_mixture is the final temperature of a mixture of two substances with masses m₁ and m₂ at temperatures T₁ and T₂. Useful for calorimetry calculations.

10

Vol._air = 78% N₂ + 21% O₂ + 1% other gases

Describes the composition of dry air, indicating the ratio of its components. Helps understand mixtures in environmental science.

Equations

1

Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

This reaction shows how calcium hydroxide reacts with carbon dioxide forming calcium carbonate and water. Key in identifying gas interactions.

2

Lime Water Reaction: Ca(OH)₂ + CO₂ → CaCO₃ (s) + H₂O

Shows the formation of precipitate in lime water upon reaction with carbon dioxide, useful in testing for CO₂ presence.

3

Air Quality Index (AQI)

A numerical scale that indicates the cleanliness of the air. Important for environmental science and health awareness.

4

Mixture Types: Homogeneous vs. Heterogeneous

Defines uniform (homogeneous) mixtures like solutions and non-uniform (heterogeneous) mixtures like salads, critical for understanding matter classifications.

5

Heat Transfer in Mixtures: Q = mcΔT

Q is the heat absorbed or released, m is mass, c is specific heat capacity, and ΔT is the change in temperature. Fundamental for thermal energy calculations.

6

F = ma

This equation represents the force acting on an object as the product of its mass (m) and acceleration (a), relevant in physical interactions of matter.

7

Hydrocarbon Combustion: C_xH_y + O₂ → CO₂ + H₂O

Represents the general reaction of hydrocarbons burning in oxygen, producing carbon dioxide and water, essential in studying combustion in mixtures.

8

N_2 + 3H_2 ↔ 2NH₃

The Haber process for ammonia synthesis. Important in chemistry, allowing the understanding of gas interactions in mixtures.

9

Saturated Solution: m_solute/m_solution × 100%

Defines saturation level in solutions, helping identify predominant components in liquid mixtures.

10

Components of Air: N₂ + O₂ + CO₂ + Water Vapour + Pollutants

Describes the main constituents of air, necessary for understanding environmental science and air quality concerns.