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, 
The answer to your problem is 0.015 liters. I got the answer because to convert cubic centimeters into liters, you need to divide the cubic centimeters by 1000.
B. A gram would have a lot more molecules of propane than a mole
Answer: There are
molecules present in 7.62 L of
at
and 722 torr.
Explanation:
Given : Volume = 7.62 L
Temperature = 
Pressure = 722 torr
1 torr = 0.00131579
Converting torr into atm as follows.

Therefore, using the ideal gas equation the number of moles are calculated as follows.
PV = nRT
where,
P = pressure
V = volume
n = number of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.

According to the mole concept, 1 mole of every substance contains
atoms. Hence, number of atoms or molecules present in 0.244 mol are calculated as follows.

Thus, we can conclude that there are
molecules present in 7.62 L of
at
and 722 torr.
Answer:
c, maybe d, and I think b.
Explanation:
Im sorry if wrong