The answers that apply include;
- A saturated fatty acid with a greater molar mass has a higher melting point than a saturated fatty acid with a low molar mass
- A saturated fatty acid has a higher melting point than an unsaturated fatty acid
Saturated acids do not have double bonds in their hydrocarbon tails. Therefore, because there are no kinks in the chains, the chains are well compacted due to numerous hydrogen bonds between each. The larger the chains (directly proportional to molar mass), the higher the melting point of these fats.
I would say C is the most correct.
In D it depends on what water source you're using. Let's say it is a waterfall, then the source of the water (melting ice or a lake) may disappear in the future.
If you're using underwater "windmills" placed in the ocean, then you would expect it to last a while as the ocean will not disappear in the near future.
Among the choices, the unit of energy is calories. Answer in 1) is D. In 2) we are given with te mass , heat and temperature change. we just need to get the heat capacity and compare it with the following metals. The calculated heat capacity is 0.46 kJ/kg K. The answer is A. iron. In 3) we can compute the heat absorbed by the formula ΔH=mCpΔT. Cp of water is 4.18 J/g K. Answer of 3) is D. In 4) the formula used in Cp=ΔH/mΔT. Answer in 4) is A. The heat of enthalpy of fusion of ice is 80 cal/g. We convert this to J/g. Answer in 5) is B.334 J/g.
