Answer:
0.49 mol
Explanation:
Step 1: Write the balanced equation
Mg + 2 HCI ⇒ MgCl₂ + H₂
Step 2: Calculate the moles corresponding to 12 g of Mg
The molar mass of Mg is 24.31 g/mol.

Step 3: Calculate the moles of H₂ produced by 0.49 moles of Mg
The molar ratio of Mg to H₂ is 1:1. The moles of H₂ produced are 1/1 × 0.49 mol = 0.49 mol.
The mineral that is the hardest known substance in nature is a diamond.
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Answer:
sodium chloride: neutral.
tomato juice: acid.
vinegar: acid.
sea water: base.
bicarbonate of sodium: base.
Explanation:
Hello there!
In this case, in agreement to the definition of the pH, as the measure of the acidity and basicity of a substance; it is important to recall that pH's below 7 stand for acidic substances and pH's above 7 stand for basic substances, whereas a pH of 7 defines a neutral one. In such a way, given the pH's of the given substances, 7, 4.05 to 4.65, around 2.5, about 8.1 and about 8.3 respectively for sodium chloride, tomato juice, vinegar, sea water, bicarbonate of sodium, it is possible to assert:
sodium chloride: neutral.
tomato juice: acid.
vinegar: acid.
sea water: base.
bicarbonate of sodium: base.
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