<span>B. type of matter that we cannot see but that we believe makes up more than 20% of the universe C. matter made of ordinary atoms, such as hydrogen or helium atoms </span>
Answer:
75.9mL of 2.75M LiOH solution
Explanation:
Molarity is an unit of concentration defined as the ratio between moles and liters. And the molar mass of LiOH is 23.95g/mol. With this information, it is possible to know the volume of solution you should add to supply 5.0g, thus:
5.0g LiOH × (1mol / 23,95g) × (1L / 2.75mol) × (1000mL / 1L) = <em>75.9mL of 2.75M LiOH solution</em>
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I hope it helps!
Use cleaning products or soap it should help get the <span>pesticide out/off.
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Answer:
67.5% ≅ 67.6%
Explanation:
Given data:
Mass of water = 17.0 g
Mass of oxygen produced (actual yield)= 10.2 g
Percent yield of oxygen = ?
Solution:
Chemical equation:
2H₂O → 2H₂ + O₂
Number of moles of water:
Number of moles = mass/ molar mass
Number of moles = 17.0 g/ 18.016 g/mol
Number of moles = 0.944 mol
Now we will compare the moles of oxygen with water to know the theoretical yield of oxygen.
H₂O : O₂
2 : 1
0.944 : 1/2×0.944 = 0.472 mol
Mass of oxygen:
Mass = number of moles× molar mass
Mass = 0.472 mol × 32 g/mol
Mass = 15.104 g
Percent yield:
Percent yield = [Actual yield / theoretical yield] × 100
Percent yield = [ 10.2 g/ 15.104 g] × 100
Percent yield = 0.675 × 100
Percent yield = 67.5%
