Heptane means seven carbon atoms and since the general formula is CnH2n+2, heptane will be C7H16
You know that you can just google it right? It has this converter.
Answer:
When chromium chloride, CrCl2, is dissolved in water, the temperature of the water decreases. ... The attractive forces between water molecules and chromium and chloride ions is stronger, because the reaction is endothermic means the energy released in formation is less than the energy required in breaking bond.
Solving part-1 only
#1
KMnO_4
- Transition metal is Manganese (Mn)
#2
Actually it's the oxidation number of Mn
Let's find how?




- x is the oxidation number
#3
- Purple as per the color of potassium permanganate
#4

"As we move through the visible spectrum of violet, blue, green, yellow, orange and red, the wavelengths become longer. The range of wavelengths (400 - 700 nm) of visible light is centrally located in the electromagnetic spectrum (Fig. 1)."
-https://www.asu.edu/courses/phs208/patternsbb/PiN/rdg/color/color.shtml