Intro to Chemistry & Moles/Mass Flashcards
What is Chemistry?
The study of matter.
What is the equation for moles?
Moles = Mass (g) / Molar Mass
What is Avogadro’s Number?
6.02*10^23
What is a Mole?
One mole is the Avogadro’s number of particles in a substance.
What are the types of chemical reactions?
Combination Decomposition Single displacement/replacement Double displacement/replacement Combustion
What is Combination?
Two or more elements combined to make one compound.
A + B - AB
What is decomposition?
The opposite of combination where one compound breaks down into elements or separate compounds.
AB - A + B
What is single replacement?
One element replaces another one in a compound.
A + BC - B +AC
What is double replacement
Two elements in two compounds switch places.
AB + CD = AD + BC
What is combustion?
Oxygen combines with a compound to give carbon dioxide and water. This is an exothermic reaction, meaning heat is given off.
AB + O2 = CO2 + H20
What are the indicators of a reaction?
Emission of light or heat, Formation of a gas, Formation of a precipitate, Change in colour Emission of odour
How do you calculate moles from mass (g)
Mass/Molar Mass
How many moles in 58.8g NaCl?
Moles = Mass / Molar Mass
Molar mass for Na = 23
Molar mass for Cl = 35.5
Molar Mass for NaCl = 23 + 35.5 = 88.5g/mol
58.8g (Mass) / 88.5 (molar mass) = 1 Mole
How many moles in 4g NaOH?
Moles = Mass / Molar Mass
Molar Mass of NaOH = 40g/mol (23 + 16 + 1)
4g/40 = 0.1 mole
How many grams in 1.5 mole CO2?
Moles = Mass / Molar Mass
Mass = Moles * Molar mass
Molar mass of CO2 = 44g/mol (12 + 162)
1.544 = 66g