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crimeas [40]
2 years ago
12

The radioisotope radon-222 has a half-life of 3.8 days. How much of a 73.9-g sample of radon- (3 222 would be left after approxi

mately 23 days?​
Chemistry
1 answer:
Novay_Z [31]2 years ago
6 0

Answer:

1.115 g

Explanation:

Applying,

R = R'2^{n/t}................... Equation 1

Where R = original sample of radon-222, R' = sample of radon-222 left after decay, n = Total time, t = half-life.

make R' the subject of the equation

R' = R/(2^{n/t})............... Equation 2

From the question,

Given: R = 73.9 g, n = 23 days, t = 3.8 days.

Substitute these values into equation 2

R' = 73.9/(2^{23/3.8})

R' = 73.9/2^{6.05}

R' = 1.115 g

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kenny6666 [7]

Answer:

The answer is "= 0.078 \ kg \ H_2".

Explanation:

calculating the moles in CH_4 =\frac{PV}{RT}

                                                =\frac{(0.58 \ atm) \times (923 \ L) }{ (0.0821 \frac{L \cdot atm}{K \cdot mol})(232^{\circ} C +273)}\\\\=\frac{(535.34 \ atm \cdot \ L) }{ (0.0821 \frac{L \cdot atm}{K \cdot mol})(505)K}\\\\=\frac{(535.34 \ atm \cdot \ L) }{ (41.4605 \frac{L \cdot atm}{mol})}\\\\= 12.9 \ mol

Eqution:

CH_4 +H_2O \to  3H_2+ CO \ (g)

Calculating the amount of H_2 produced:

= 12.9 \ mol CH_4 \times  \frac{3 \ mol \ H_2 }{1 \ mol \ CH_4}\times \frac{2.016 g H_2}{1 \ mol \ H_2}\\\\= 78 \ g \ H_2 \\\\= 0.078 \ kg \ H_2

So, the amount of dihydrogen produced = 0.078 \frac{kg}{s}

5 0
3 years ago
3. How many moles in 28 grams of CO2?
Burka [1]

Answer:

0.636 moles

Explanation:

6 0
2 years ago
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Nostrana [21]

Answer:

6 x 10⁶ g Fe

Explanation:

Step 1: Set up dimensional analysis

7 x 10²⁸ atoms Fe (1 mol Fe/6.02 x 10²³ atoms Fe)(55.85 g Fe/1 mol Fe)

Step 2: Multiply, divide, and cancel out units

atoms Fe and atoms Fe cancel out.

mol Fe and mol Fe cancel out.

We should be left with g Fe.

7 x 10²⁸/6.02 x 10²³ = 116279 mol Fe

116279(55.85) = 6.49 x 10⁶ g Fe

Step 3: Sig figs

There is only 1 sig fig in this problem.

6.49 x 10⁶ g Fe ≈ 6 x 10⁶ g Fe

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3 years ago
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Answer:

W and X

Explanation:

isotopes : are masses of atoms with the same number of proton and electron but different neutron .

W and X have the same number of protons and different number of neutrons.

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2 years ago
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