y10D UNIT 4 and 5 bingo
4.1 what does every element have of his own ?
every element has a chemical symbol
4.1 how can we work the formula of a compound?
the formula of a compound can be worked out from the valency of the elements present
4.2 what are the two types of formulas for molecules and what do each one shows ?
the molecular formula: shows the number of each type of atom present and the empirical formula: shows the simplest whole number ratio of the different atoms present.
4.2 how can we find the formula of an ionic compound
the formula of an ionic compound can be worked out using the charges on the ions
4.3 in a chemical reactions the mass of the product is always equal to .......
the mass of the reactants
4.4 what is the name given to the ions that do not take part in the reaction ?
5.1 for what do we use simple proportion ?
we can use it to calculate the mass of a product formed if we have enough information
5.2 what is the mass of sodium hydroxide in 0.5 moles of sodium hydroxide?
Mr of NAOH = 40
to find the mass we need to multiply the number of moles (0.5) by the molar mass (40) which would give you 20 g NaOH
answer = 20 g of NaOH
5.3 how can we work out which reagent is limited ?
we can work it out by comparing the number of moles of each reactant.
5.4 how can we find the percentage of a mass of an element in a compound
it can be found using the relative formula masses and relative formula masses