Answer:
Explanation:
scheelite is CaWO₄
Mol weight = 288
80 g of scheelite = 80 / 288 = 27.77 x 10⁻² moles
27.77 x 10⁻² moles of scheelite = 27.77 x 10⁻² x 6.02 x 10²³ molecules of scheelite
= 167.17 x 10²¹ molecules of scheelite
1 molecule of scheelite contains 4 atoms of oxygen
167.77 x 10²¹ molecules of scheelite contains 4 x 167.77 x 10²¹ atoms of oxygen .
= 671.08 x 10²¹ atoms of oxygen .
= 671 x 10²¹ atoms .
Answer:
https://www.wolframalpha.com/
Explanation:
Answer:
254.5 K
Explanation:
Data Given
initial volume V1 of neon gas = 12.5 L
final Volume V2 of neon gas = 10.5 L
initial Temperature T1 of neon gas = 30 °C
convert Temperature to Kelvin
T1 = °C +273
T1 = 30°C + 273 = 303 K
final Temperature T2 of neon gas = ?
Solution:
This problem will be solved by using Charles' law equation at constant pressure.
The formula used
V1 / T1 = V2 / T2
As we have to find out Temperature, so rearrange the above equation
T2 = V2 x T1 / V1
Put value from the data given
T2 = 10.5 L x 303 K / 12.5 L
T2 = 254.5K
So the final Temperature of neon gas = 254.5 K
You have to use the combined gas law (P₁V₁/T₁=P₂V₂/T₂) and solve for P₂ to get P₂=P₁V₁T₂/T₁V₂.
You need to convert all of the temperature values into terms of Kelvin so -50°C turns into 223K and 102°C turns to 375K. After you make that conversion you can just plug in all of the values into the idea gas law and you should get P₂=228.5kpa.
I hope this helps. Let me know if anything is unclear.
