Answer:
2.4 moles of oxygen are needed to react with 87 g of aluminium.
Explanation:
Chemical equation:
4Al(s) + 3O₂(l) → 2AlO₃(s)
Given data:
Mass of aluminium = 87 g
Moles of oxygen needed = ?
Solution:
Moles of aluminium:
Number of moles of aluminium= Mass/ molar mass
Number of moles of aluminium= 87 g/ 27 g/mol
Number of moles of aluminium= 3.2 mol
Now we will compare the moles of aluminium with oxygen.
Al : O₂
4 : 3
3.2 : 3/4×3.2 = 2.4 mol
2.4 moles of oxygen are needed to react with 87 g of aluminium.
Answer:
fossil
Explanation:
the dead organism is called a fossil i think
Insulation wraps because independent is the variable you are changing to affect the dependent variable (what you are measuring)
Critical Thinking Questions
1. Why do you think forensic scientists are so careful that the tests they do are sensitive, reproducible, and specific? What might happen if they were less careful about this?
They have to be careful to ensure as much accuracy as possible.
2.Which type of evidence do you think is most useful in an investigation? Why?
Physical evidence would probably be most important because it is the best way to connect someone directly with that crime.
3.Why do you think that forensic scientists continue to look for class characteristics given their limitations?
Class characteristics are good in court because it provides details of different aspects of the crime.
