Answer:
Mass = 58.96 g
Explanation:
Given data:
Mass of CH₄ = 21.5 g
Mass of O₂ = 387.5 g
Mass of CO₂ formed = ?
Solution:
Chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
Number of moles of CH₄:
Number of moles = mass / molar mass
Number of moles = 21.5 g/ 16 g/mol
Number of moles = 1.34 mol
Number of moles of O₂ :
Number of moles = mass / molar mass
Number of moles = 387.5 g/ 32 g/mol
Number of moles = 12.1 mol
now we will compare the moles of CO₂ with O₂ and CH₄.
O₂ : CO₂
2 : 1
12.1 : 1/2×12.1 = 6.05 mol
CH₄ : CO₂
1 : 1
1.34 : 1.34
Number of moles of CO₂ produced by CH₄ are less thus it will limiting reactant.
Mass of CO₂:
Mass = number of moles × molar mass
Mass = 1.34 mol × 44 g/mol
Mass = 58.96 g
Earth, Air, Water, and Fire
<u>Answer:</u> The age of the mineral sample is 
<u>Explanation:</u>
The equation used to calculate rate constant from given half life for first order kinetics:
where,
= half life of the reaction = 
Putting values in above equation, we get:
We are given:
Mass ratio of K-40 to Ar-40 = 0.812 : 1.00
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = 
t = time taken for decay process = ? yr
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount of the sample = [1.00 + 0.812] = 1.812 grams
[A] = amount left after decay process = 1.00 grams
Putting values in above equation, we get:
Hence, the age of the mineral sample is
Answer:
The footprints of a dinosaur and the burrow of an ancient shrimp are examples of - Trace Fossils
Explanation:
A trace fossil or ichnofossil is defined as a geological record of biological activity. These provide us with indirect evidence of life in the past, such as the footprints, burrows, tracks, borings, etc that are left behind by animals, rather than the preserved remains of the body of the actual animal itself.
