From ideal gas equation that is PV=nRT
n(number of moles)=PV/RT
P=760 torr
V=4.50L
R(gas constant =62.363667torr/l/mol
T=273 +273=298k
n is therefore (760torr x4.50L) /62.36367 torr/L/mol x298k =0.184moles
the molar mass of NO2 is 46 therefore density= 0.184 x 46=8.464g/l
Answer:
The answer is D; 1.45 x 10^-4
Should be 18, well i guess I have to have 20 characters so good luck
The 2.5 x 10²¹ molecules of CH₃OH have 0.00415 moles.
<h3>What is the mole concept?</h3>
- The Mole concept is used to express the amount of substance conveniently.
- A mole is defined as the amount of substance that contains exactly 6.022 x 10²³ elementary particles of the given substance. Here, elementary particles refer to atoms, molecules, or ions.
- This fixed number 6.022 x 10²³ is known as Avogadro Number and is denoted by

<h3>How to calculate the number of moles?</h3>
The number of moles is given by

When given mass = molar mass of a substance, then no of moles is equal to 1 which is equivalent to 6.022 x 10²³.
We also know,
1 mole has 6.022 x 10²³ molecules of CH₃OH
According to the mole concept,
6.022 x 10²³ molecules of CH₃OH is equal to 1 mole
2.5 x 10²¹molecules of CH₃OH is equal to
moles
Thus, 2.5 x 10²¹molecules of CH₃OH are equal to 4.15 x 10⁻³ moles or 0.00415 moles
Learn more about the mole concept:
brainly.com/question/1427235
#SPJ1