Answer:
mass O2 = 222.5 g
Explanation:
- %wt = ((mass compound)/(mass sln))×100
balance reaction:
∴ %wt H2 = 11 % = ((mass H2)/(mass H2O))×100
∴ %wt O2 = 89 % = ((mass O2)/(mass H2O))×100
∴ mass H2O 250 g
⇒ mass O2 = (0.89)(250 g)
⇒ mass O2 = 222.5 g
Answer:approx 300,000 years ago
Explanation:
Fossils attributed to H. sapiens, along with stone tools, dated to approximately 300,000 years ago, found at Jebel Irhoud, Morocco yield the earliest fossil evidence for anatomically modern Homo sapiens
Answer: Water must be present for this reaction to occur.
Explanation:
Decomposition reactions require breaking of bonds which require energy and thus all of the decomposition reactions are endothermic reactions.
The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid form are represented by (s) whereas liquids are represented by (l) and gases are represented by (g) after their chemical formulas.
The balanced chemical reaction of
decomposition is:

The decomposition of
requires heat and leads to formation of CaO as solid and
as product.
Thus the the statement that is not true is Water must be present for this reaction to occur.