Answer:
The answer to your question is 98.9 %
Explanation:
Data
moles of methane = CH₄ = 2.0
excess air
Percent yield = ?
mass of CO₂ = 87 g
- Balanced chemical reaction
CH₄ + 2O₂ ⇒ CO₂ + 2H₂O
Reactants Elements Products
1 C 1
4 H 2
4 O 2
- Calculate the molar mass of CH₄
CH₄ = 12 + 4 = 16 g
- Convert the moles to mass
16 g of CH₄ ----------------- 1 mol
x ----------------- 2 moles
x = (2 x 16) / 1
x = 32 g of CH₄
-Calculate the theoretical formation of CO₂
16 g of CH₄ ----------------- 44 g of CO₂
32 g of CH₄ ---------------- x
x = (32 x 44) / 16
x = 88 g of CO₂
-Calculate the Percent yield
Percent yield = Actual yield/Theoretical yield x 100
Percent yield = 87/88 x 100
Percent yield = 98.9 %
<span>ANSWER:
Electrical energy accelerates the electrons in the neon gas. The gas ionizes and becomes plasma, containing both positive and negative ions.</span>
Explanation:
A change that does not cause any change in chemical composition of a substance is known as a physical change.
For example, mass, density, volume etc are all physical changes.
On the other hand, a change that brings change in chemical composition of a substance is known as chemical change.
For example, combustion, toxicity, reactivity etc are all chemical changes.
Hence, following statements are identified as chemical or physical changes as follows.
(a) Oxygen gas supports combustion : Chemical change
(b) Fertilizers help to increase agricultural production : Chemical change
(c) Water boils below 
on top of a mountain : Physical change
(d) Lead is denser than aluminum : Physical change
(e) Uranium is a radioactive element : Chemical change
Answer:
It will increase the rate of chemical weathering.
Explanation:
Weathering is the breaking down or dissolving of rocks and minerals on the surface of the earth into smaller grains or soil.
Weathering can occur either by biological, chemical or mechanical means.
When mechanical (or physical) weathering breaks a small boulder into pieces, this will lead to an increase in the rate of chemical weathering.
Chemical weathering involves chemical reactions or changes that occur in rocks which results in changes in their size and composition. This chemical reactions that breaks down rocks include hydrolysis by water and oxidation by oxygen. <em>The rate of chemical reactions increase with increase in surface area of the substances reacting.</em>
When the boulder is broken into smaller pieces, it exposes a larger area of these rocks to the chemical reactions that weather rocks. For example, a larger surface of the rock may be exposed to water result in faster reaction of the rock salts with water, and thus, the rock particles are broken down faster.
