I think it's DNA forms a double helix and RNA consists a single strand.
I may be wrong...
Answer : The energy required to melt 58.3 g of solid n-butane is, 4.66 kJ
Explanation :
First we have to calculate the moles of n-butane.

Given:
Molar mass of n-butane = 58.12 g/mole
Mass of n-butane = 58.3 g
Now put all the given values in the above expression, we get:

Now we have to calculate the energy required.

where,
Q = energy required
= enthalpy of fusion of solid n-butane = 4.66 kJ/mol
n = moles = 1.00 mol
Now put all the given values in the above expression, we get:

Thus, the energy required to melt 58.3 g of solid n-butane is, 4.66 kJ
Answer:
B 1,3
Explanation:
Count the atoms on each side of the arrow, they have to be equal
After arrow
2x C
6x O
4x H
Before the arrow
2x C - correct, as it is the only compound with C then there must only be 1 mole of it.
This is also the correct amount of H
We need 6x O total so 6/2 = 3
So there are 3 moles of O