We know this because of the discovery of fossils and bones. We can find out roughly when they existed because of carbon dating.
Answer:
The aspirin is more soluble in ethanol than water - the water helps the crystals separate from solution.
Explanation:
Hope this helps!
Answer:
a.
ZnS(s) + O2(g) → ZnO(s) + SO2(g)
b.
HCl (aq) + Ba(OH)2(aq) → BaCl2(aq) + H2O
Given 3.72 g of P and 21.28g of Cl, converting these to moles: ( 3.72 g P)(mol P/30.97 g P) = 0.12 mol P (21.28 g Cl)(mol Cl/35.45 g Cl) = 0.60 mol Cl P:Cl = 0.12/0.60, therefore P: Cl =1/5 Therefore, PCl5 hope it helps
