<span>It is the variable in an experiment is not directly altered</span>
Answer:
Microbial mats.
Explanation:
Microbes formed sheets that were able to capture layers of sediment is called microbial mats. These mats of microbes provide good fossil evidence to the researchers. These microbial mats consist of bacteria and archaea which is considered the earliest form of life on earth. These microbial mats grow on moist places as compared to dry environment. About 3,500 million years ago, these microbes are the most important members of earth and maintainers of the ecosystems.
I think they describe a structure of cyclopentane. Cyclopentane is a highly flammable alicyclic hydrocarbon with a chemical formula C₅H₁₀, consisting of a ring of five carbon atoms each bonded to hydrogen atoms above and below the plane. It occurs as a colorless liquid with a petrol-like odor.
Answer:
CH₄ is the excess reagent and SO₄²⁻ is the limiting reagent.
0.040 g
Explanation:
Step 1: Write the balanced reaction for the methane anaerobic oxidation
CH₄ + SO₄²⁻ ⇒ S²⁻ + CO₂ + 2 H₂O
Step 2: Establish the theoretical mass ratio between the reactants
According to the balanced equation, the theoretical mass ratio of CH₄ to SO₄²⁻ is 16.04:96.06 = 0.1670:1
Step 3: Establish the experimental mass ratio between the reactants
50 mg (0.050 g) of CH₄ react with 60 mg (0.060 g) of SO₄²⁻. The experimental mass ratio of CH₄ to SO₄²⁻ is 0.050:0.060 = 0.83:1
Comparing both mass ratios, we can deduce that CH₄ is the excess reagent and SO₄²⁻ is the limiting reagent.
Step 4: Calculate the mass excess of CH₄
The mass of CH₄ that reacts with 0.060 g of SO₄²⁻ is:
0.060 g SO₄²⁻ 16.04 g CH₄/96.06 g SO₄²⁻ = 0.010 g CH₄
The mass excess of CH₄ is:
0.050 g - 0.010 g = 0.040 g
