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微观探析是认识物质的一种途径。设

N_{\mathrm{A}}

为阿优加德罗常数，下列有关说法正确的是 A. $1.8 \mathrm{gD}_{2} \...

Mar 19, 2024

微观探析是认识物质的一种途径。设

N_{\mathrm{A}}

为阿优加德罗常数，下列有关说法正确的是 A.

1.8 \mathrm{gD}_{2} \mathrm{O}

中含有的中子数目为

N_{\mathrm{A}}

1 \mathrm{~mol} / \mathrm{LCuCl}_{2}

溶液中含有

\mathrm{Cu}^{2+}

的数目小于

N_{\mathrm{A}}

46 \mathrm{gNO}_{2}

与

\mathrm{N}_{2} \mathrm{O}_{4}

的混合物中含有的分子数为

N_{\mathrm{A}}

25^{\circ} \mathrm{C} ， 101 \mathrm{kPa} ， 2.45 \mathrm{LCl}_{2}

与

\mathrm{NaOH}^{2}

溶液完全反应，转移电子数目为

0.1 N_{\mathrm{A}}

Key Concept

Molar mass and Avogadro's number

Explanation

1.8 \text{ g}

\text{D}_2\text{O}

(heavy water) contains

N_{\mathrm{A}}

molecules, since the molar mass of

\text{D}_2\text{O}

20 \text{ g/mol}

. Each molecule has one oxygen atom with 8 neutrons and two deuterium atoms with one neutron each, totaling 10 neutrons per molecule. Therefore,

1.8 \text{ g}

\text{D}_2\text{O}

contains

0.09 \text{ mol}

, which is

0.09 \times N_{\mathrm{A}}

molecules, and

0.09 \times N_{\mathrm{A}} \times 10

neutrons, which is not equal to

N_{\mathrm{A}}