Balance the combustion reaction:
a C₂H₂ + b O₂ → c CO₂ + d H₂O
Count the atoms on both sides of the reaction:
• C : 2a = c
• H : 2a = 2d
• O : 2b = 2c + d
Let a = 1; then c = 2 and d = 1, and it follows that
2b = 2•2 + 1 = 5
so that b = 5/2, and the balanced reaction is
1 C₂H₂ + 5/2 O₂ → 2 CO₂ + 1 H₂O
or, with integer coefficients,
2 C₂H₂ + 5 O₂ → 4 CO₂ + 2 H₂O
C₂H₂ has a molar mass of about 26.038 g/mol, so we have a starting amount of
(64.0 g) (1/26.038 mol/g) ≈ 2.46 mol C₂H₂
According to the reaction, we produce H₂O in a 1-to-1 ratio with the C₂H₂ that is burned up, so we end up with about 2.46 mol H₂O.
The correct statements are:
1. The dinosaur and the mammoth existed after the trilobites.
The trilobites are a species that appeared and existed much earlier than any dinosaur or later mammals like the mammoth. The difference in their existence is few hundred million years, and while the trilobites are primitive life form, the dinosaurs and mammoths are much newer, better evolved species.
3. The trilobites and the armored fish died before the dinosaur.
Before the dinosaurs appeared, there were many other species that lived before them, some of which are the trilobites and the armored fish. The trilobites being one of the oldest species, and the armored fish being a more evolved but still primitive fish with exoskeleton. Both of them existed in periods prior to the dinosaur domination.
Answer:
If you want me to answer you gotta put a picture of the line graph.
