Basic Concepts Of Chemistry Flashcards
Define Matter
Anything which has mass and occupies space is called matter.
What are the 3 major states of matter? Define their properties.
Solids - Particles and held very closely and tightly. Have definite volume and shape.
Liquids - Particles are close to each other but they can move around. Have definite volume but takes shape of container.
Gases - Particles are very far apart and movement is easy and fast. Neither definite shape nor volume.
What are the 3 major states of matter? Define their properties.
Solids - Particles and held very closely and tightly. Have definite volume and shape.
Liquids - Particles are close to each other but they can move around. Have definite volume but takes shape of container.
Gases - Particles are very far apart and movement is easy and fast. Neither definite shape nor volume.
Matter can be divided into 2 categories:
Pure Substance: All constituent particles of a substance are same in chemical nature.
Mixture: Contains particles of two or more pure Substances which may be present it in any ratio.
A mixture may be:
Homogeneous: components mix completely. Uniform distribution of particles.
Heterogeneous: Not uniform composition, seperate particles may be visible.
Pure Substances can be classified as:
Elements: consists of only one type of atoms. May exist as atom or molecule. Properties of atoms of an element are constant throughout.
Compounds: Two or more atoms of different elements combine together in a definite ratio, molecule of a compound is obtained. Properties of a compound are different from those of it’s constituent elements.
Define SI unit and it’s constituents:
International System of Units or SI have seven base or fundamental quantities which are:
Length [L] (metre)
Mass [M] (kg)
Time [T] (secs)
Temprature [θ] or [0] (kelvin)
Current [A] or [I] (ampere)
Amount of Substance [N] (mole)
Luminous Intensity [J] or [I] (candela)
Prefixes for SI Units?
Femto
Pico
Nano
Differentiate between Mass and Weight? How is mass of a substance determined?
Mass of a substance is the amount of matter present in it, while weight is the force exerted by gravity on an object.
The mass of a substance is constant, whereas, it’s weight may vary from one place to another due to change in gravity.
Mass of a substance can be determined accurately in the laboratory by using an Analytical Balance.
Define Volume. How is it measured in labs?
Volume is the amount of space occupied by a substance, it has the units of l^3.
In the labs, volume of liquids or solutions can be measured by graduated cylinders, burette, pipette, etc. Volumetric Flask is used to prepare a known volume of a solution.
Temprature Info?
Temprature has 3 common scales to be measured by: Celsius, Kelvin, Fahrenheit.
Celsius scale is calibrated from 0° to 100° (freezing point to boiling point).
Fahrenheit scale is calibrated between 32° to 212°
Relations:
C/5 = (F-32)/9
K = C + 273
In kelvin scale, negative values are not possible.
What is exponential notation?
N × n^10
The uncertainty in the experimental or the calculated values is indicated by mentioning the number of ________________?
Significant Figures
Differentiate between Precision and Accuracy.
Precision refers to the closeness od various measurements for the same quantity.
Accuracy: is the agreement of a particular value to the true value if the result.
Rules for addition and subtraction of Significant Figures?
Result cannot have more digits to the right of the decimal point then either of the original numbers.
