Chemistry, 13.04.2021 02:30 Reijected

Finely cut up some leaves and fill a mortar to about 2 cm depth. Add a pinch of sand and about six drops of propanone from the teat pipette. Grind the mixture with a pestle for at least three minutes. On a strip of chromatography paper, draw a pencil line 3 cm from the bottom. Use a fine glass tube to put liquid from the leaf extract onto the centre of the line. Keep the spot as small as possible. Allow the spot to dry, then add another spot on top. Add five more drops of solution, letting each one dry before putting on the next. The idea is to build up a very concentrated small spot on the paper. Attach the paper to the pencil using sellotape so that when placed in the beaker, the paper is just clear of its base. Place no more than about 10 cm3 of propanone in the beaker and hang the paper so it dips in the propanone. Ensure the propanone level is below the spot.

Answers: 3

Show answers

Another question on Chemistry

Chemistry, 22.06.2019 09:00

Which process does not require the presence of a physical substance in order to transfer heat? air in the atmosphere is heated by the ground. this warm air then rises, and cooler air falls. this is an example of what type of process? how is conduction different from radiation?

Answers: 1

Answer

Chemistry, 22.06.2019 14:30

100 grams of molten lead (600°c) is used to make musket balls. if the lead shot is allowed to cool to room temperature (21°c), what is the change in entropy (in j/k) of the lead? (for the specific heat of molten and solid lead use 1.29 j/g⋅°c; the latent heat of fusion and the melting point of lead are 2.45 × 104 j/kg and 327°c, respectively.)

Answers: 1

Answer

Chemistry, 22.06.2019 17:20

Pegmatites are igneous rocks in which the individual minerals are very large. typically, the minerals are all light-colored quartz, feldspar and muscovite. if you were given a black and white photograph of a pegmatite in a quarry (where the rock has been blasted and broken), what physical properties could you use to identify those three minerals in this hypothetical photo? describe each mineral and the specific diagnostic properties. be specific.

Answers: 2

Answer

Chemistry, 22.06.2019 17:30

What will most likely happen in the absence of a cell membrane? a) photosynthesis will not take place. b) the cell will not store food, water, nutrients, and waste. c) energy will not be released during cellular respiration. d) substances will pass in and out of the cell in an uncontrolled manner.

Answers: 1

Answer

You know the right answer?

Finely cut up some leaves and fill a mortar to about 2 cm depth. Add a pinch of sand and about six d...

Questions