EL6 What Are We Made Of? Flashcards
What is one mole of a substance?
The amount of substance that contains as many particles as there are atoms in exactly 12g of ^12C.
What is the value of Avogadro’s constant?
6.022 times 10^23
What is Avogadro’s constant?
The number of atoms per mole as a value of 6.022*10^23.
What tells us one mole of a specific substance?
Its relative atomic mass (g).
What is the molar mass?
The mass of one mole of substance (relative atomic mass).
What is the unit for molar mass?
g mol^-1 (grams per mole).
How do you calculate moles?
Mass (g)/ molar mass (g mol^-1)
What is the relative formula mass?
The sum of the relative atomic masses of a compound’s elements.
What is the empirical formula?
The simplest whole number ratio of atoms of each element present in a compound.
What is the molecular formulae?
The number and type of atoms of each element in a molecule.
What are the units of molar gas volume?
dm^3/mol.
What are water of crystallisations?
Water molecules that are fit within an ionic lattice in a regular manner.
What do the crystals of some ionic lattices’ contain?
Water molecules.
What are crystals within an ionic lattice said to be?
Hydrated.
What happens when hydrated crystals are heated?
The water of crystallisation is removed as steam leaving the anhydrous solid.
How do you work out the formula of hydrated compounds?
Measure the mass of a sample of hydrated salt, heat the salt and measure the mass at regular intervals, and when no more mass is lost the formula can be determined.
What factors can reduce the amount a product is produced?
Loss of products from reaction vessels, side reactions occurring producing unwanted by-products, impurities in the reactants, changes in temp and pressure, and if the reaction is an equilibrium system.
What is the experimental yield?
The reduced amount of products.
What is the theoretical yield?
The maximum yield.
What is the equation for percentage yield?
Experimental yield/ theoretical yield *100.
How can the theoretical yield be calculated?
From the balanced equation for the particular reaction.
