<span>1. What is the colour of FeSO4.7H20 crystals?How does this colour change upon heating?
</span><span>Melanterite or FeSO4.7H20 is green in color
</span>2FeSO4 ---> Fe2O3 + SO2 + SO3<span>
2. a. What are redox reactions?
It </span><span>is a type of chemical </span>reaction<span> that involves a transfer of electrons between two species.
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b.Why is the reaction between MnO2 and HCl a
redox reaction?
Because there are atoms that are reduced and are oxidized.
c.Identify the substance oxidized and the
substance reduced in the above reaction.
</span>MnO2<span> + 4 </span>HCl<span> ---> MnCl2 + 2H2O + Cl2
</span>Mn was reduced and Cl was oxidized
Answer is: c. CuSO4 + 2NaOH yields Cu(OH)2 + Na2SO4.
Copper atom has oxidation number +2, sulfur atom oxidation number +6, oxygen has oxidation number-2, sodium has oxidation number +1 and hydrogen has +1 on both side of chemical reaction, so elements did not change their oxidation numbers.
The particles are quite tightly packed together but still have enough room to be able to move and flow, their bonds aren't as strong as a solids are
Based upon Max Planck's theory of black-body radiation, Einstein theorized that the energy in each quantum of light was equal to the frequency multiplied by a constant, later called Planck's constant. A photon above a threshold frequency has the required energy to eject a single electron, creating the observed effect.
