Chemical Reactions+ Chemistry of Gases Flashcards
revise
What is the test for oxygen?
It will relight a glowing splint
What is the test for hydrogen?
It burns with a pop
What is the difference between normal air and breathed out air?
There is less oxygen in breathed out air.
How do you calculate the % of oxygen in the air?
%oxygen in air= height water rose/ height of cylinder * 100
What is the value of oxygen in the air?
20.95%
How do you test for carbon dioxide?
-Turns lime water cloudy
-causes bubbles with a milky appearance
Why is helium good for airships?
-low density
-light
-not flammable
-less dense than air
Name 4 types of energy.
-light
-heat
-sound
-kinetic
What are the characteristics of a chemical reaction?
-colour change
-energy change
-solid is formed
-new substance is produced
What is the concentration of salt in seawater in grams per litre?
20cm3 of salt was measured and weighed out and placed into an evaporating basin. The basin was then heated to evaporate the water. The basin was then re-weighed and the mass of salt calculated in 1L
How do you calculate the amount of salt in 1L of seawater
In 20cm3 seawater…
weight of empty basin=5.4
weight of empty basin+salt=5.6
salt= 0.2
0.2x50=10
10g of salt
What oxygen essential for?
combustion
What is catalyst?
reaction
can be speeded up using it
