Nitrate bottle #2 contains an ingredient which settles on the bottom of the bottle between uses. The shaking is needed to mix it back into the liquid again, and you shake the test tube as well to keep it in the liquid until it starts to react.
When you first buy it, or if you haven't used it for weeks, this ingredient can solidify into a lump so it is recommended in these circumstances that you tap the bottle on the worktop a few times first to break up any lumps, and then start shaking.
And it's add 10 drops bottle #1, mix for a few seconds, shake bottle #2 for 2 mins, add 10 drops, shake the test tube for 1 min (not 2), then wait 5 mins and look at the colour. I usually time the shaking using the wall clock which has a second hand, then use a kitchen timer for the 5 minutes wait.
When you first buy it, or if you haven't used it for weeks, this ingredient can solidify into a lump so it is recommended in these circumstances that you tap the bottle on the worktop a few times first to break up any lumps, and then start shaking.
And it's add 10 drops bottle #1, mix for a few seconds, shake bottle #2 for 2 mins, add 10 drops, shake the test tube for 1 min (not 2), then wait 5 mins and look at the colour. I usually time the shaking using the wall clock which has a second hand, then use a kitchen timer for the 5 minutes wait.
