I think the answer is b hope this helps
Answer:
Mass = 8 g
Explanation:
Given data:
Mass of MgO formed = 20 g
Mass of oxygen needed = ?
Solution:
Chemical equation:
2Mg + O₂ → 2MgO
Number of moles of MgO:
Number of moles = mass/molar mass
Number of moles = 20 g/ 40 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of MgO and O₂ from balance chemical equation:
MgO : O₂
2 : 1
0.5 : 1/2×0.5 = 0.25 mol
Mass of oxygen required:
Mass = number of moles × molar mass
Molar mass of O₂ is 32 g/mol
Mass = 0.25 mol × 32 g/mol
Mass = 8 g
It's 3. There are two Cl in the reactants and 3 in the products, and they need to be balanced/equal. Only way to do that is add three on the left side, which will give you 6 Cl (3×2Cl) and then 2 on the other side, which will also give you 6 Cl (2×3Cl)
Answer:
i think interstellar dust......
