Using the periodic table, answer the following question..How many atoms of neon are in 0.378g of neon (a) 6.02 x 10²³ atoms (b)

Question

blondinia [14]

3 years ago

7

Using the periodic table, answer the following question..How many atoms of neon are in 0.378g of neon (a) 6.02 x 10²³ atoms (b)

1.87 x 10‐²atoms (c) 2.28 x 10²³ atoms (d)1.13 x 10²² atoms.

Chemistry

2 answers:

zmey [24] · Answer 1 · 2022-07-06T08:41:45+03:00

zmey [24]3 years ago

7 0

Answer:

B 1.87×10^-²

Explanation:

20.1797 g Neon = 1 mol

0.378 g Neon = y

(Cross multiply)

20.1797y= 0.378 x 1

(Make y the subject of the formula)

y = 0.878/ 20.1787

y = 0.0187317

y = 0.0187 approx

y = 1.87 x 10^-²

stira [4] · Answer 2 · 2022-07-06T10:32:16+03:00

The correct answer is D. 1.13 x 10^22 atoms are present in 0.378 g of neon. Avogadro's number (6.022 x 10^23) gives the ratio of representative particles per mole of substance. For every mole of substance, there are 6.022 x 10^23 representative particles present. Since 0.378 g of neon is less than one mole of neon, the answer should be less than Avogadro's number, which makes option D a logical answer.

Further Explanation:

To get the number of atoms present in 0.378 g of neon the following steps must be done:

Convert the mass of neon into moles.
Use Avogadro's number to get the number of atoms present in the given moles of neon.

STEP 1: Convert 0.378 g of Neon to moles of Neon

$moles \ of \ neon \ = 0.378 \ g \ Ne (\frac{1 \ mol \ Ne}{20.1797 \ g \ Ne})\\\\\boxed {moles \ of \ Ne \ = 0.018732 \ mol}$

STEP 2: Use Avogadro's number to calculate the number of atoms of Ne

$no. \ of \ atoms \ Ne \ = 0.018732 \ mol \ Ne \ (\frac{6.022 \ x \ 10^{23} \ Ne \ atoms}{1 \ mol \ Ne})\\\\ no. \ of \ atoms \ Ne \ = 1.128 \ x \ 10^{22} \ atoms$

Since the given, 0.378 g has 3 significant figures, the final answer must also have 3 significant figures. Therefore,

$\boxed {no. \ of \ atoms \ Ne \ = 1.13 \ x \ 10^{22} \ atoms}$

A. 6.02 x 10^23 atoms is FALSE because the given amount of neon is less than one mole. Hence, the number of atoms cannot be equal to Avogadro's number.

B. 1.187 x 10^-2 atoms is FALSE because atoms are very very small particles. It will require a large number of atoms to make up something that is measurable like a 0.378 g sample of neon. Having less than 1 atom to make up this much sample is not logical.

C. 2.28 x 10^23 atoms is FALSE because this much atoms make up 0.3781 mol of Neon but the given is 0.378 <u>grams</u> not moles of Ne.

D. 1.13 x 10^22 atoms is TRUE because the value is less than 6.022 x 10^23 which is logical since the sample is less than 1 mole.

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