I think it’s A because each unit is worth 3
A and C are incorrect because they are not complete transfer of valence electrons. Ionic bonds best to form a neutral molecule
Answer:
1.35 g
Explanation:
Data Given:
mass of Potassium Permagnate (KMnO₄) = 3.34 g
Mass of Oxygen: ?
Solution:
First find the percentage composition of Oxygen in Potassium Permagnate (KMnO₄)
So,
Molar Mass of KMnO₄ = 39 + 55 + 4(16)
Molar Mass of KMnO₄ = 158 g/mol
Calculate the mole percent composition of Oxygen in Potassium Permagnate (KMnO₄).
Mass contributed by Oxygen (O) = 4 (16) = 64 g
Since the percentage of compound is 100
So,
Percent of Oxygen (O) = 64 / 158 x 100
Percent of Oxygen (O) = 40.5 %
It means that for ever gram of Potassium Permagnate (KMnO₄) there is 0.405 g of Oxygen (O) is present.
So,
for the 3.34 grams of Potassium Permagnate (KMnO₄) the mass of Oxygen will be
mass of Oxygen (O) = 0.405 x 3.34 g
mass of Oxygen (O) = 1.35 g
Answer: 43.3 l
Explanation:
1) Chemical equation:
2 Li(s) + 2 H₂O (l) → 2LiOH(aq) + H₂ (g)
2) Mole ratios:
2 mol Li : 2 mol H₂O : 2 mol LiOH : 1 mol H₂
3) Number of moles of Li that react
n = mass in grams / atomic mass = 24.6g / 6.941 g/mol = 3.54 moles
4) Yield
Proportion:
2 mol Li / 1 mol H₂ = 3.54 mol Li/ x
⇒ x = 3.54 mol Li × 1 mol H / 2 mol Li = 1.77 mol H₂
4) Ideal gas equation
PV = nRT ⇒ V = nRT / P
V = 1.77 mol × 0.0821 [atm×l / (mol×K)] × 301 K / 1.01 atm = 43.3 l
V = 43.3 l ← answer
The pebbles become smooth and even because of erosion. the waves from the sea rub against the pebbles this is erosion. x
