# Calculating Density of NH3: Step-by-Step Guide

In summary, the problem is to find the molecular weight of NH3 and the density in Kg/m^3. The molecular weight is 17.03g/mol and the actual density is 0.771 kg/m^3. To find the density, you can use the ideal gas law and convert the volume of 22.4 L/mol to m^3. The molecular mass per mol is already known. After converting, the density comes out to be 0.760 kg/m^3. However, the 22.4 L/mol value may vary for different gases.

## Homework Statement

OK, the problem says to find the molecular weight of NH3.

It is 17.03g/mol.

Next, you are supposed to find the density(in Kg/m^3) for the NH3.

I'm not sure how you do this part. I don't know if I have to convert or what.

I know the actual density is 0.771 kg/m^3.

D=M/V

## The Attempt at a Solution

It's a gas, you can probably treat it with the properties of an ideal gas. Like so many mols of an ideal gas at STP has a certain volume...etc. Think ideal gas law.

Does that help?

Well kinda I guess.

I know my chemistry(a little)...but I'm just confused(or thinking too much).

I know that at STP...volume is 22.4 L

Temp is 273.15K
Pressure is 1 atm
n is usually 1 mole

So how does that relate to density though...do i just divide my mass by the 22.4?(I can't see the units working out)

Small correction: at STP, the volume of an ideal gas is 22.4 L/mol. Liters are a way of expressing volume, right? So convert that to m^3. You already figured out the molecular mass per mol. Just look at the units (make sure everything is consistent).

ok...got that figured out...thanks for your help. Came out to be .760kg/m^3.

Yeah, the 22.4 L/mol isn't exactly the same for all gases, so depending on where you got the accepted value it might vary a bit.

## 1. What is the formula for calculating density of NH3?

The formula for calculating density of NH3 is mass divided by volume, or D = m/V.

## 2. What units should be used when calculating density of NH3?

The units used for mass should be in grams (g) and the units used for volume should be in cubic centimeters (cm3) or milliliters (mL).

## 3. How do I find the mass of NH3?

To find the mass of NH3, you will need to measure the amount of NH3 in grams using a scale or balance.

## 4. How do I find the volume of NH3?

The volume of NH3 can be found by measuring the amount of NH3 in cubic centimeters (cm3) or milliliters (mL) using a graduated cylinder or other measuring tool.

## 5. What is the density of NH3 at standard temperature and pressure (STP)?

The density of NH3 at STP is approximately 0.771 grams per cubic centimeter (g/cm3). However, this value may vary slightly depending on the temperature and pressure conditions.