How many molecules are in 20.0 g no2

2.62 × 10^23 molecules

Explanation:

We are required to determine the number of molecules in 20.0 g of NO₂

We are going to use the following simple steps;

Step 1: Calculate the number of moles of NO₂

Moles = Mass ÷ Molar mass

Molar mass of NO₂ = 46.0 g/mol

Therefore;

Moles of NO₂ = 20 g ÷ 46.0 g/mol

                       = 0.435 moles

Step 2: Calculate the number of molecules

We need to know, 1 mole of a gas contains molecules equivalent to the Avogadro's number, 6.022 × 10^23.

Therefore; 1 mole of NO₂ = 6.022 × 10^23 molecules

Number of molecules = Moles × Avogadro's number

                                    = 0.435 moles × 6.022 × 10^23 molecules/mole

                                    = 2.62 × 10^23 molecules

Thus, there are 2.62 × 10^23 molecules in 20 g of NO₂

Molarity is moles of solute over liters of solution. idk if that is what you are talking about, but you can convert moles of solute to grams of solute using dimensional analyzes by using molar mass found on the periodic table.

We first assume that this gas is an ideal gas where it follows the ideal gas equation. the said equation is expressed as: pv = nrt. from this equation, we can predict the changes in the pressure, volume and temperature. if the volume and the temperature of this gas is doubled, then the pressure still stays the same.