Answer:
True
Explanation:
Yes.
The distance that the molecules move depends on their solubility in the solvent and the size of the molecules. Heavy molecules will travel slower and therefore travel a shorter distance in the time the chromatography is run.
We know from such things as felt tip pens that colourings can be soluble in different solvents. Water soluble felt pens have colours that are - well - water soluble. Permanent felt pens have colours that are insoluble in water but that are soluble in another solvent. This could well be alcohol.
The water soluble colours may also be soluble in alcohol. The solubility in alcohol will be different from the solubility in alcohol, and so the Rf value ( the distance travelled) will also be different.
Because of the complicated shapes of the colours, the colours may not have the same order in the Rf values in the different solvents.
Answer:
C) The nucleus emits particles and/or energy
Explanation:
A key example of this is uranium, as when it decays it emits protons and neutrons, backing up our answer of C.
In the modern periodic table the elements are arranged in order of increasing atomic number.
Answer:
1.3 mol H₂O
Explanation:
Let's consider the decomposition reaction of ammonium perchlorate.
NH₄ClO₄(s) → 1/2 N₂(g) + 1/2 Cl₂(g) + O₂(g) + 2 H₂O(g)
As we can see in the balanced equation, the molar ratio of ammonium perchlorate to water is 1:2. The moles of water produced by the reaction of 2.5 mol of ammonium perchlorate.
2.5 mol NH₄ClO₄ × (2 mol H₂O / 1 mol NH₄ClO₄) = 1.3 mol H₂O
1 mole of NH4NO3 requires absorption of 25.7 kJ/mol.
Therefore; 1 kJ of heat energy is absorbed by dissolving 1/25.7 moles of NH4NO3.
Hence; For an energy of 73.0 kJ to be absorbed the moles of NH4NO3 that dissolves will be;
= (1/25.7 × 73)
= 2.84 moles
Hence; 73 kJ is absorbed by dissolving 2.84 moles of NH4NO3.
