Answer:
Alumminum hydroxide reacts with sulfuric acid as follows: 2Al(OH)3+H2SO4-->Al2(SO4)+6H2O.
Explanation:
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Answer:
B. chemical
Explanation:
Chemical change cannot go back to its original form
Fossils provide a window in Earth's history by showing us how they existed in the past. They can be dated through several ways and can show us how animals and plants have evolved over millions of years. Also, fossils can help us better understand ancient disasters by the inclusion of elements (such as <span>volcanic ash or dust from major space object impacts) and how they affected the life on earth)</span>
Answer:
3.56x10^24 molecules
Explanation:
The following data were obtained from the question:
Mass of Na2SO4 = 840g
Molar Mass of Na2SO4 = (23 x2) + 32 + (16x4) =46 + 12 + 64 = 142g/mol
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This also gives that 1mole of Na2SO4 contains 6.02x10^23 molecules.
If 1 mole (i.e 142g) contains 6.02x10^23 molecules,
Therefore, 840g of Na2SO4 will contain = (840 x 6.02x10^23)/142 = 3.56x10^24 molecules