<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.
</span><span>
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
First, we have to get:
1- The heat required to increase T of ice from -50 to 0 °C:
according to q formula:
q1 = m*C*ΔT
when m is the mass of ice = mol * molar mass
= 1 mol * 18 mol/g
= 18 g
and C is the specific heat capacity of ice = 2.09 J/g-K
and ΔT change in temperature = 0- (-50) = 50°C
by substitution:
∴q1 = 18 g * 2.09 J/g-K *50°C
= 1881 J = 1.881 KJ
2- the heat required to melt this mass of ice is :
q2 = n*ΔHfus
when n is the number of moles of ice = 1 mol
and ΔHfus = 6.01 KJ/mol
by substitution:
q2 = 1 mol * 6.01 KJ/mol
= 6.01 KJ
3- the heat required to increase the water temperature from 0°C to 60 °C is:
q3 = m*C*ΔT
when m is the mass of water = 18 g
C is the specific heat capacity of water = 4.18 J/g-K
ΔT is the change of Temperature of water = 60°C - 0°C = 60°C
by substitution:
∴q3 = 18 g * 4.18 J/g-K * 60°C
= 4514 J = 4.514 KJ
∴the total change of enthalpy = q1+q2+q3
= 1.881 KJ +6.01 KJ + 4.514 KJ
= 12.405 KJ
Answer: There are
atoms present in 0.500 mol of
.
Explanation:
According to the mole concept, there are
atoms present in 1 mole of a substance.
In a molecule of
there is only one carbon atom present. Therefore, number of carbon atoms present in 0.500 mol of
are as follows.

Thus, we can conclude that there are
atoms present in 0.500 mol of
.
<h2>Answer:</h2>
It means the waves collides and constructive interference occurred.
<h3>Explanation:</h3>
If the two waves coming from the opposite direction collide with each other, there are two way of their interference.
- Constructive interference: An interference which results in the increase in energy. And it is when crust of a wave comes on the crust of second wave.
- Destructive interference: An interference which results in decrease in energy of the resulting wave and colliding waves cancel the result of each other.
Hence in experiment there will be constructive interference.