Which observation illustrates the law of conservation of mass?

A/an _______ is the smallest unit of matter that has the characteristics of a chemical element.

julsineya [31]

Answer:

The answer is atom.

Explanation:

7 0

2 years ago

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If 16.00 g of O₂ reacts with 80.00 g NO, how many the excess reactant are left over? (enter only the value, round to whole numbe

pishuonlain [190]

Answer:

50

Explanation:

We will need a balanced equation with masses, moles, and molar masses of the compounds involved.

1. Gather all the information in one place with molar masses above the formulas and masses below them.

Mᵣ: 30.01 32.00 46.01

2NO + O₂ ⟶ 2NO₂

Mass/g: 80.00 16.00

2. Calculate the moles of each reactant

$\text{moles of NO} = \text{80.00 g NO} \times \dfrac{\text{1 mol NO}}{\text{30.01 g NO}} = \text{2.666 mol NO}\\\\\text{moles of O}_{2} = \text{16.00 g O}_{2} \times \dfrac{\text{1 mol O}_{2}}{\text{32.00 g O}_{2}} = \text{0.5000 mol O}_{2}$

3. Calculate the moles of NO₂ we can obtain from each reactant

From NO:

The molar ratio is 2 mol NO₂:2 mol NO

$\text{Moles of NO}_{2} = \text{2.333 mol NO} \times \dfrac{\text{2 mol NO}_{2}}{\text{2 mol NO}} = \text{2.333 mol NO}_{2}$

From O₂:

The molar ratio is 2 mol NO₂:1 mol O₂

$\text{Moles of NO}_{2} = \text{0.5000 mol O}_{2}\times \dfrac{\text{2 mol NO}_{2}}{\text{1 mol Cl}_{2}} = \text{1.000 mol NO}_{2}$

4. Identify the limiting and excess reactants

The limiting reactant is O₂ because it gives the smaller amount of NO₂.

The excess reactant is NO.

5. Mass of excess reactant

(a) Moles of NO reacted

The molar ratio is 2 mol NO:1 mol O₂

$\text{Moles reacted} = \text{0.500 mol O}_{2} \times \dfrac{\text{2 mol NO}}{\text{1 mol O}_{2}} = \text{1.000 mol NO}$

(b) Mass of NO reacted

$\text{Mass reacted} = \text{1.000 mol NO} \times \dfrac{\text{30.01 g NO}}{\text{1 mol NO}} = \text{30.01 g NO}$

(c) Mass of NO remaining

Mass remaining = original mass – mass reacted = (80.00 - 30.01) g = 50 g NO

5 0

3 years ago

Match these items

masha68 [24]

The correct matches are as follows:

1.instantaneous combustion
G.burning

2.mass of substances before and after a reaction is the same
C.Law of Conservation of Matter

3.substances that combine
A.reactants

4. Yields or makes
B.arrow symbol

5.rapid oxidation
F.explosion

6.new substance
D.product

7.slow oxidation
E.rust

Hope this answers the question. Have a nice day.

4 0

3 years ago

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A certain gas is present in a 15.0 LL cylinder at 2.0 atmatm pressure. If the pressure is increased to 4.0 atmatm the volume of

Helga [31]

Explanation:

According to Boyle's law, pressure of a gas is inversely proportional to its volume at constant temperature and moles.

Mathematically, P = $\frac{k}{V}$

where, k = proportionality constant

Also, formula for initial pressure and volume is as follows.

$P_{i} = \frac{k_{i}}{V_{i}}$

or, $k_{i} = P_{i} \times V_{i}$

= $2 atm \times 15 L$

= 30 atm L

Now, we will calculate the value of $k_{f}$ as follows.

$k_{f} = P_{f} \times V_{f}$

= $4 atm \times 7.5 L$

= 30 atm L

Hence, as $k_{i} = k_{f}$ this means that it signifies that gas obeys boyle's law.

6 0

3 years ago

What information does an empirical formula give?

r-ruslan [8.4K]

Answer:

C. The lowest whole-number ratio of atoms in a molecule.

Explanation:

Hello there!

In this case, according to the definition of the empirical and the molecular equations, it is possible for us to consider the following example of molecular formula, C4H10, whose empirical formula is C2H5.

In such a way, it is possible for us to say that the empirical formula gives C. The lowest whole-number ratio of atoms in a molecule, as it is the result of the simplification of the molecular formula when possible.

Regards!

3 0

3 years ago