How many molecules are there in 4.00 moles of glucose, C6H12O6? 4.00 moles = 4.00 x 6.022 x 10^23 molecules = 2.4088 x 10^24 molecules When the units are set up properly, the unit you are converting FROM will cancel out: You are left with the desired unit you are converting TO. 3. How many moles are 20 x 10^23 atoms of phosphorus? 20 x 10^23 atoms = 20 x 10^23 / 6.022 x 10^23 = 3.32 moles How many atoms are in 0.750 moles of zinc? 0.750 moles = 0.750 x 6.022 x 10^23 atoms = 4.5165 x 10^23 atoms How many molecules are in 0.400 moles of NO2? 0.400 moles = 0.400 x 6.022 x 10^23 molecules = 2.4088 x 10^23 molecules 6. How many atoms are in 0.340 moles of sodium? 0.340 moles = 0.340 x 6.022 x 10^23 atoms = 2.04908 x 10^23 atoms How many moles are in 204 x 10^23 molecules of Bromine? 204 x 10^23 molecules = 204 x 10^23 / 6.022 x 10^23 = 3.388 moles How many molecules are in 0.75 moles of oxygen gas? 0.75 moles = 0.75 x 6.022 x 10^23 molecules = 4.5165 x 10^23 molecules How many moles are present in 2.45 x 10^23 molecules of CH4? 2.45 x 10^23 molecules = 2.45 x 10^23 / 6.022 x 10^23 = 0.406 moles How many moles are there in 3.4 x 10^23 molecules of NH3? 3.4 x 10^23 molecules = 3.4 x 10^23 / 6.022 x 10^23 = 0.564 moles
The Correct Answer and Explanation is:
Correct Answer:
How many moles are there in 3.4 × 10²³ molecules of NH₃?Moles of NH₃=3.4×1023 molecules6.022×1023 molecules/mol≈0.564 moles\text{Moles of NH₃} = \frac{3.4 \times 10^{23} \text{ molecules}}{6.022 \times 10^{23} \text{ molecules/mol}} \approx 0.564 \text{ moles}Moles of NH₃=6.022×1023 molecules/mol3.4×1023 molecules≈0.564 moles
Explanation:
In chemistry, the concept of the mole allows scientists to count particles like atoms, ions, or molecules by weighing them. This is essential because individual particles are so small that counting them one by one isn’t practical. To bridge the gap between the microscopic world and measurable quantities, we use Avogadro’s number, which is:6.022×1023 particles/mole6.022 \times 10^{23} \text{ particles/mole}6.022×1023 particles/mole
This number represents how many particles (atoms, molecules, etc.) are in one mole of a substance. When converting between number of particles and moles, Avogadro’s number acts as a conversion factor.
Let’s apply this to the question: How many moles are in 3.4 × 10²³ molecules of ammonia (NH₃)?
To find the number of moles, divide the number of molecules by Avogadro’s number:3.4×10236.022×1023≈0.564 moles\frac{3.4 \times 10^{23}}{6.022 \times 10^{23}} \approx 0.564 \text{ moles}6.022×10233.4×1023≈0.564 moles
This calculation shows that 3.4 × 10²³ molecules of NH₃ is equal to about 0.564 moles.
Why It Works:
- You’re converting from molecules (a count) to moles (an amount of substance).
- The unit “molecules” cancels out, and you’re left with the unit “moles”.
- This type of dimensional analysis ensures accuracy and consistency.
Tip:
Always remember:
- Multiply when converting from moles to particles.
- Divide when converting from particles to moles.
This simple rule helps avoid confusion and ensures correct application of Avogadro’s number in any mole-particle conversion.
