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4 years ago

Which of the following correctly illustrates the mass of reactants and products for the reaction below?

Chemistry

1 answer:

Marina CMI [18]4 years ago

3 0

Answer:

The mass of reactants and products for the reaction is this:

- 92 g Na, 32 g O₂, 124 g Na₂O

which is not a choice from the list.

Explanation:

4 moles of Na reacts with 1 mol of oxygen to produce 2 moles of sodium oxide.

Na = 23 g/m

4 moles are (4 . 23) = 92 g

O₂ = 32 g/m

It's a diatomic molecule (each O is 16 g/m)

Na₂O = 62 g/m

2 mol of sodium oxide will be (2 .62) = 124 grams

The mass of reactants and products for the reaction is this:

- 92 g Na, 32 g O₂, 124 g Na₂O

which is not a choice from the list.

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11. Propane (C3Hg) is a fuel commonly used in gas grills.

Mrac [35]

Answer:

81.71%

Explanation:

One mole of propane contains 3 moles of carbon atoms and 8 moles of hydrogen atoms, as seen from the molecular formula of $C_3H_8$ . In order to calculate the percent of carbon in propane by mass, we need to remember that %w/w (or percent mass) formula states that:

$\omega=\frac{m_{component}}{m_{total}}\cdot100\%$

That is, we need to divide the mass of the component of interest by the total mass of the compound and multiply by 100 to obtain the percentage.

For simplicity, let's take 1 mole of propane and find the mass of 1 mole (hence, we'll be finding the molar mass of propane). To do that, we add the 3 molar masses of carbon and 8 molar masses of hydrogen to obtain a total of:

$M_{C_3H_8}=3M_C+8M_H=3\cdot12.011 \frac{g}{mol}+8\cdot1.00784\frac{g}{mol}=44.096 \frac{g}{mol}$

Now that we have the molar mass of propane, we also need to find the total mass of carbon in 1 mole of propane. We know that we have a total of 3 moles of carbon which corresponds to:

$M_C=3\cdot12.011 \frac{g}{mol}=36.033 \frac{g}{mol}$

Dividing the mass of carbon present by the total mass of the compound will yield the mass percentage as defined by the formula we introduced:

$\omega_C=\frac{36.033\frac{g}{mol}}{44.096 \frac{g}{mol}}\cdot 100\%=81.71\%$

5 0

3 years ago

After decaying for 48 hours, 1/16 of the original mass of a radioisotope sample remains unchanged. What is the half life of this

nika2105 [10]

The half life of this radioisotope is 12 hours.

<u>Explanation:</u>

The length of time it requires to break down for an initial half amount or the amount of time taken to transform half of a reactant into product. Half of a particular sample took the time to experience radioactive decay. The time it would take to degrade radioactively into another component or nuclide for half of the atoms of an unstable element or nuclide.

If 1/16 of the sample remains it predicts that there were 4 half-life periods then 16 = 2⁴

4 half-life periods = 48 hours / 4

half-life period = 12 hours.

3 0

3 years ago

How many grams of C are there in 0.234 moles of caffeine?

elixir [45]

Solo lo ago para obtener puntos jejeje

8 0

3 years ago

You are assigned the task of separating a desired granular material, with a density of 3.26 g/cm3, from an undesired granular ma

Svetradugi [14.3K]

Answer:

diiodomethane

Explanation:

The densities of each of the liquids mentioned in the question are stated below;

CCl4- 1.59 g/cm^3

Hexane- 0.672 g/cm^3

Benzene- 0.8765 g/cm^3

Diiodomethane- 3.3 g/cm^3

Clearly, the density of diiodomethane methane is almost the same as that of the desired granular material, hence the undesired granular material having a density of 2.04 g/cm3 will float in diiodomethane thus separating the two granular materials.

5 0

3 years ago

Why are isotopes with short half-lives not useful for dating very old rocks?

seropon [69]

Answer:

because not enough of the parent isotope remains to measure accurately. because not enough of the daughter product has formed to be detectable.

Explanation:

Hope it helps

6 0

3 years ago