Answer: number of atoms is 5.21 · 10^24
Explanation: Atomic mass of Be is 9.012 g/mol.
Number of moles n = m/M = 78.0 g / 9.012 g/mol =
Multiply this with Avogadro number Na = 6.022*10^23 1/mol
Answer : The volume of oxygen at STP is 112.0665 L
Solution : Given,
The number of moles of
= 5 moles
At STP, the temperature is 273 K and pressure is 1 atm.
Using ideal gas law equation :

where,
P = pressure of gas
V = volume of gas
n = the number of moles
T = temperature of gas
R = gas constant = 0.0821 L atm/mole K (Given)
By rearranging the above ideal gas law equation, we get

Now put all the given values in this expression, we get the value of volume.

Therefore, the volume of oxygen at STP is 112.0665 L
Answer:
Explanation:
Different butterfly species occupy slightly different niches, but most are forest- or field-dwelling, flying, nectar-feeding insects. ... During feeding, butterflies are often covered in pollen, making them effective agents of pollination for plants.
Answer:
The answer to your question is 122.4 g of O₂
Explanation:
Data
mass of O₂ = ?
moles of H₂O = 7.65
Process
1.- Write the balanced chemical reaction
2H₂O ⇒ 2H₂ + O₂
2.- Convert the moles of H₂O to grams
molar mass of H₂O = 2 + 16 = 18 g
18 g of H₂O ---------------- 1 mol
x ----------------- 7.65 moles
x = (7.65 x 18) / 1
x = 137.7 g H₂O
3.- Calculate the grams of O₂
36 g of H₂O -------------------- 32 g of O₂
137.7 g of H₂O ------------------- x
x = (32 x 137.7) / 36
x = 122.4 g of O₂