Moles of ca3(po4)2 = 23.7 / 310.17 = 0.076
moles of (PO4)3- = 0.076 x 2 = 0.152
now, no. of ions = 0.152 x 6.022 x 10^{23}
= 9.2 x 10^{22}
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.
dinosaur footprint
Explanation:
A dinosaur footprint is an example of a trace fossil. A trace fossil is a type of fossil that shows the activities of organisms that lived in the past.
- Fossils are the preserved remains of organisms that lived several years ago.
- Fossils are usually found in sedimentary rocks and thick layers of ice in temperate and polar regions.
- Body fossils are the remains of the body parts of an organism that has been preserved. They can be skeletal parts, teeth, eggs e.t.c
- A trace fossil shows the preserved remains of the activities of an organism.
- They can be fingerprints, burrows and borings, feccal pellets e.t.c
Learn more":
fossils and evolution brainly.com/question/12790206
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