The answer is 1. CO. A gram-molecular mass is defined as mass in grams numerically equal to the molecular weight of a substance or the sum of all the atomic masses in its molecular formula. Since CO2 and CO has both carbon and oxygen, the gram-molecular mass does not change. For a compound with carbon and oxygen, the molecular mass comes respectively from 12 (atomic mass of carbon) + (2 × 16) (atomic mass of oxygen), which is 44 g.
Answer : The mass of the water in two significant figures is, 
Explanation :
In this case the heat given by the hot body is equal to the heat taken by the cold body.


where,
= specific heat of iron metal = 
= specific heat of water = 
= mass of iron metal = 32.3 g
= mass of water = ?
= final temperature of mixture = 
= initial temperature of iron metal = 
= initial temperature of water = 
Now put all the given values in the above formula, we get


Therefore, the mass of the water in two significant figures is, 
A) acids because they start with h
Answer:
v = 23.96 cm³
Explanation:
Given data:
Mass = 15.0 g
Density = 0.626 g/cm³
Volume = ?
Solution:
Formula:
D=m/v
D= density
m=mass
V=volume
Now we will put the values in formula:
d = m/v
v = m/d
v = 15 g / 0.626 g/cm³
v = 23.96 cm³
I believe the best description comparing the structure of carbohydrates and nucleic acids would be A.