I am pretty sure the answer is D
The empirical formula of the substance would be 
<h3>Empirical formula calculation</h3>
The constituents of the compound are as follows:
N = 54/201.6 = 26.78% = 26.78/14 = 1.91 moles
H = 15/201.6 = 7.44% = 7.44/1 = 7.44 moles
Cl = 132.6/201.6 = 65.48% = 65.48/35.5 = 1.84 moles
Divide the number of moles by the smallest"
N = 1.91/1.84 = 1
H = 7.44/1.84 = 4
Cl = 1.84/1.84 = 1
Thus, the empirical formula is 
More on empirical formula can be found here: brainly.com/question/14044066
#SPJ1
Answer:

Explanation:
The concentration of CO2 in the room will be the amount of CO2 in the room at time t, divided by the volume of the room.
Let A(t) be the amount of CO2 in the room, in ft3 CO2.
The air entering the room is 3000 ft3/min with 0.06% concentrarion of CO2. That can be expressed as (3000*0.06/100)=1.8 ft3 CO2/min.
The mixture leaves at 3000 ft3/min but with concentration A(t)/V. We can express the amount of CO2 leaving the room at any time is A(t).
We can write this as a differential equation

We can rearrange and integrate

We also know that A(0) = 12000*(0.3/100)=36 ft3 CO2.

Then we have the amount A(t) as

Rome is in Italy, which is represented by D.