Grade 11 Chemistry Quantities and Stoichiometry Test Notes PDF

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SCH3U Grade 11 Chemistry Quantities and Stoichiometry Test Notes
Chemistry Quantities Unit Test Study Notes 11 practice material quiz work and more...

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Chemistry Quantities Unit Test Study Notes ● Isotopes and average atomic mass ○ Isotope: element variations with different atomic mass but same atomic number ○ Isotopic Abundance: the relative amount in which each isotope of an element ○ Calculating: given 2 isotopes of an element [B: 10.01u] [B: 11.01u] ■ 1) Given average atomic mass: 10.81u ■ If given percentages, you can find average atomic mass by adding each portion ○ 2) Set variables for unknown values ■ Let x represent % abundance for 10/5 B ■ Let 1-x represent % abundance for 11/5 B ○ Calculate: ■ 10.01x+(1-x)11.01=10.81 ■ 10.01x+11.01-11.01x=10.81 ■ -1.00x=0.2 ■ X=0.2 ■ The Mole and Avogadro’s constant ■ Mole: the SI unit that is used to measure how much of a substance. (balanced eqn coefficient are moles) ■ Converting Moles -> number of particles ■ Number of Moles = number of particles / Avogadro’s constant ■ Avogadro’s constant: 6.02214179 x 10^23 ● Converting Moles to Mass/molar mass ○ Molar Mass: how much grams per mol of an element = atomic mass ○ Number of Moles = mass / Molar Mass ○ Percentage Composition ■ Laws of definite proportions: a law stating that a chemical compound always contains the same proportion of elements by mass ■ Mass percentages (H in H2O) = molar mass of H (1.01) / molar mass of H2O (18.02) = 11.2% ■ Empirical Formula

■ A formula that shows the smallest whole number ratio of elements within a compound ■ Lactic Acid: a chemical name ■ Empirical Formula: CH2O ■ Molecular Formula: C3H6O3 ● Calculations: when given percentage composition of different elements ○ 1) Find the number of moles for each element (assume % is per 100g for simplicity) ○ 2) Divide all the moles by the smallest number mole to reduce the decimals ○ 3) If not whole numbers yet, multiply by some special factors to reduce decimals ■ 1.25 x ¼ = 1 Al2(SO4)3 +

3 Cu : 2:3:1:3 ratio ● To determine amounts, use ratio and plug in numbers correctly ● Limiting/excess reactants ○ Limiting:Reactants that are not completely used up in a reaction ■ When this reactant is used up, the reaction stops ● Excess Reactants:the reactant that is left over after a reaction is over ○ Regardless of how much excess remains, the reaction will stop once the limiting is used ● When 2 or more reactants seem limiting, one must pick the reactant that is limiting all the others ● Mass to mass Stoichiometry ○ Converting mass through stoichiometry then to another mass ○ Process: ■ 1) Balance equation ■ 2) Convert mass to moles ■ 3) perform mole to mole ratio ■ 4) convert new mole back to mass ■ Finding Hydrate ■ Given a hydrate, and when hydrate is evaporated, and new mass is taken, how much of the hydrate was there? ■ Process ■ 1) find mole of non-hydrate portion ■ 2) find mass of the water that evaporated ■ 3) find mole of H2O ■ 4) based on ratio, find out how many mols of water should exist ■ Based on the amount of amount of actual results in ratio with theoretical ratio ■ Find the amount that were theoretical

based on regular ratios of stoichiometry ■ (OR: divide by the smallest mole to get rid of as much decimals) ■ ○ Competing Reaction ■ Other reactions will happen at the same time, limiting the reactant produced ○ Reaction Rate ■ Slow reactions take longer than time allocated to complete, collected immaturely ○ Purity of reactant ■ Contaminants in the reaction are unaccounted for in the initial calculations ○ Laboratory Techniques ■ Improper techniques leads to loss of reactants and reactants ■ Soluble solvent in filtrate instead of filter paper ■ Soluble products washed away in rinsing ■ Instruments used weren’t accounted for ● When looking for masses ○ Look for ratio of compound to water ○ Compare ratio with amount of solvents used, there’s the grams ○ Nuclear reactions ■ Involves changes to the nucleus of the reactants ■ Changes the number of protons or neutrons ● 3 Types of nuclear reactions ○ Alpha ParticleDecay (a decay) ■ Loss of 2 protons and 2 neutrons ■ Always creates 4/2 He product ○ Beta Particle Decay(b decay) ■ Loss of an electron-like beta particle ■ 0/1 e always a product, adds one neutron to other product ○ Gamma Decay(Y decay) ■ Releases beta particle as well as gamma energy

● Conditions of nuclear reactions ○ Sum of mass numbers of product = sum of mass numbers of reactants ○ Sum of atomic numbers of product = sum of atomic numbers reactants ● Nuclear Fission ○ Occurs when an unstable isotope splits into smaller fragments. Multiple neutrons released along with high energy (radiation) ● Nuclear Fusion ○ Nucleus absorbs particles, merging 2 atomic nuclei together

● Tracing transmission of a disease and aiding in the development and testing of treatments ● Increase crop yield ● Pest resistance ● Environmental conservation of organisms (if one species of cat is in danger, another cat species can be as well) Phylogenetic trees ~show evolutionary relationships amongst species ● Roots/base = oldest ancestors ● Upper ends = present day ● Forks = points where an ancestral species split/evolved to become two species Kingdoms and Domains ~Kingdoms are based on number of cells, presence or absence of a nucleus, and the mode of reproduction/nutrition ~A domain is a taxon higher than kingdom, and it’s based on two major cell types ● Prokaryotic (before nucleus) are the most ancient, no membrane bound nucleus’ (e.g. bacteria) ● Eukaryotic (true nucleus) have a membrane bound nucleus, they are more complex and contain more organelles (e.g. plant and animal cells) ~Domains with the respective kingdoms: 1. Bacteria (includes bacteria kingdom) 2. Archaea (includes archaebacteria kingdom) 3. Eukarya (includes plants, fungi, animals, and protists) Dichotomous Keys ~An identification tool that has two part choices that lead users to a correct identification ~Used to identify organisms Viruses ~Non-cellular particles that do not embody characteristics of living organisms ~Can only exist as intracellular parasites Viral Structure

~RNA or DNA is enclosed in a protein coat called a capsid ~Size is measured in nanometers (1nm = 10−9 m) ~Capsids have different shapes (cylindrical, spherical, and cubicle) which aids scientists in...