A "neon" sign contains 2.4¡Ñ10^2mL of argon. Assuming that the gas is at standard temperature and pressure, there is 1.00 moles of gas per 22.4 L of volume. How many argon atoms are present in this sign?
a. 6.5¡Ñ1021
b. 2.8¡Ñ1022
c. 3.2¡Ñ1024
d. 9.9¡Ñ10-23
See your post above.
To calculate the number of argon atoms present in the neon sign, we can follow these steps:
Step 1: Calculate the volume of argon gas using the given information.
The sign contains 2.4×10^2 mL of argon gas. However, we need the volume in liters to use the conversion factor correctly, so we divide by 1000:
Volume of argon gas = 2.4×10^2 mL ÷ 1000 = 0.24 L
Step 2: Determine the number of moles of argon gas using the given volume and the fact that there is 1.00 mole per 22.4 L of volume at standard temperature and pressure.
Number of moles of argon gas = 0.24 L ÷ 22.4 L/mole = 0.01071 moles
Step 3: Convert moles to atoms using Avogadro's number.
Avogadro's number states that 1 mole of any substance contains 6.022×10^23 atoms.
Number of argon atoms = 0.01071 moles × 6.022×10^23 atoms/mole = 6.45×10^21 atoms
Therefore, the number of argon atoms present in the neon sign is approximately 6.45×10^21 atoms.
The correct answer is option: a. 6.5×10^21.