<span>Fe(NO3)2
The NO3 part is a poly-atomic ion with total charge -1.
This is because Fe has a +2 charge and two NO3's with a -1 charge will balance out to 0.
Most often we just make the assumption that Oxygen has a -2 oxidation number because it is very electro-negative.
So to find N, we just need an oxidation number that balances out with 3(-2) to get -1 (the total charge of the ion)</span>
I think it’s B 5.54 x 10^2g
Answer:
M = 20.5 g/mol
Explanation:
Given data:
Volume of gas = 1.20 L
Mass of gas = 1.10 g
Temperature and pressure = standard
Solution:
First of all we will calculate the density.
Formula:
d = mass/ volume
d = 1.10 g/ 1.20 L
d = 0.92 g/L
Now we will calculate the molar mass.
d = PM/RT
0.92 g/L = 1 atm × M / 0.0821 atm.L/mol.K ×273.15 K
M = 0.92 g/L × 0.0821 atm.L/mol.K ×273.15 K / 1 atm
M = 20.5 g/mol
The heat lost is 
The heat lost when the ice is cooled from 400k to 263K can be calculated using the formula of heat transfer.
<h3>Heat Transfer</h3>
This is the heat transferred from a body of higher temperature to a body of lower temperature.

- Q = Heat Transfer
- m = mass = 1277g
- ΔT = change in temperature

We converted the temperature from kelvin scale into Celsius scale and find the change in temperature.
Solving for heat transfer

The heat loss is approximately 
Learn more on heat transfer here;
brainly.com/question/16055406