Answer:

Explanation:
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In this case, according to the given data of volume, pressure and temperature, it is possible to infer this problem can be solved via the combined gas law:

Thus, regarding the question, we evidence we need V2, but first we make sure the temperatures are in Kelvins:

Then, we obtain:

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Answer:
0.4 moles of water produced by 6.25 g of oxygen.
Explanation:
Given data:
Mass of oxygen = 6.25 g
Moles of water produced = ?
Solution:
Chemical equation;
2H₂ + O₂ → 2H₂O
Number of moles of oxygen:
Number of moles = mass/ molar mass
Number of moles = 6.35 g/ 32 g/mol
Number of moles = 0.2 mol
Now we will compare the moles of oxygen with water:
O₂ : H₂O
1 : 2
0.2 : 2×0.2 = 0.4 mol
0.4 moles of water produced by 6.25 g of oxygen.
The answer is C, hydrogen gas. This is because in single replacement reactions, the single element (here Magnesium) replaces whichever element in the compound it corresponds to. Because Mg loses electrons since it’s a metal, it will replace the element which also loses electrons, which is Hydrogen here. So when they switch places, MgCl2 and H2 are made— and H2 is the hydrogen gas.
Answer:
An element is a pure substance as well, because if we fill up a balloon with just helium gas ,it will only contain helium atoms
Atomic number
Atoms of different elements must have different atomic number. The atomic number of each element is different than other Elements.