F5 Chem molar volume of g

2011-04-23 1:03 am

Which of the following contains the largest number of ATOMS at room temperature and pressure?
[ Relative atomic masses: H = 1.0, N = 14.0, Cl = 35.5; molar volume of gas at room temperature and pressure = 24dm^3]

A. 2 mol of ammonium gas
B. 3 mol of nitrogen gas
C. 7g of hydrogen gas
D. 90dm^3 of hydrogen chloride gas

Ans: A. Why?

回答 (1)

知識就是力量

2011-04-23 2:01 am

✔ 最佳答案

Denote the Avogadro's constant as L.
No. of atoms of ammonia gas (NH3 - 4 atoms) = 2 * 4 * L = 8L

No. of atoms of nitrogen gas (N2 - 2 atoms) = 3 * 2 * L = 6L

No. of moles of hydrogen gas = 7 / 2 = 3.5 mol
No. of atoms of hydrogen gas (H2 - 2 atoms) = 3.5 * 2 * L = 7L

No. of moles of hydrogen chloride gas = 90 / 24 = 3.75 mol
No. of atoms of hydrogen chloride gas (HCl - 2 atoms) = 3.75 * 2 * L = 7.5L

Therefore, the largest number of atoms at room temp. and pressure is ammonia gas.

參考: Knowledge is power.

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