SC14-16, pg 65-71
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
卡片预览 (19 张)
what are titrations used to find out?
the concentration , how much acid is needed to neutralise a given quantity of alkali (or vice versa)
what are the first steps of titration
measure out a set volume of the alkali into flask using a pipette and then add a few drops of indicator
what does a burette do in the titration
adds the acid to the alkali a small amount at a time
what is the equation for concentration
concentration= number of moles/volume of solution
how do you calculate the percentage yield
percentage yield =actual yield /theoretical yield x 100
what is the yield
the amount of product you get from a reaction
what are some of the reasons why a 100% yield never happens in real life :(
-incomplete reactions -practical looses -unwanted reactions
how do you calculate the atom economy
total Mr of desired products/total Mr of all products x 100
what is atom economy
the % of reactants that get turned into useful products
why is high atom economy important in industrial reactions
means resources are used up slower and less waste is produced which reduces cost
what affects how quickly equilibrium is reached
temperature, pressure, concentration, rate of reaction and catalysts
what do fertilisers do and how
help plants grow faster and bigger by supplying them with elements that they need
what are the three essential elements in fertilisers
nitrogen, phosphorous and potassium
what advantages do ammonia fertilisers have over traditional fertilisers
they are soluble, and you can control the amount of chemicals in them, as well as how much is made
how is the molar volume calculated
molar volume=gas volume / number of moles
what does avagadros law state
that under the same conditions the same number of moles of different gases all occupy the same volume, so all gases have the same molar volume at RTP-24 dm3 mol-1
what do fuel cells do
use fuel and oxygen to produce electrical energy
what fuel do hydrogen-oxygen cells use
hydrogen
what is one advantage and one disadvantage of using fuel cells for energy
adv- they don’t generate pollutants disadv- hydrogen is very explosive