Answer:
78g
Explanation:
Given parameters:
Mass of oxygen gas = 16g
Mass of potassium oxide = 94g
Unknown:
Mass of reacting potassium = ?
Solution:
To solve this problem, we need to obtain a balanced reaction equation. Then determine the number of moles of the reactant and use it to find that of the other one.
Balanced equation:
4K + O₂ → 2K₂O
Number of moles of reacting oxygen;
Number of moles = 
molar mass of O₂ = 2 x 16 = 32g/mole
Number of moles =
= 0.5mole
From the reaction equation;
4 mole of K reacted with 1 mole of O₂;
x mole of K will react with 0.5 mole of O₂
Therefore, 4 x 0.5 = 2 moles of potassium.
Mass of potassium = number of moles x molar mass
Molar mass of potassium = 39g
Mass of potassium = 2 x 39 = 78g
Answer:
The potential difference across a given given wire of an circuit is directly proportional to the current flowing through it provided it's temperature remains the same. This is known as ohm's law
V is proportional to I
V/I = constant
V/I = R
V = IR where R is the constant of proportionality and resistance of the wire
Hope this helps!
As time goes on, members of a population with favorable traits continue to breed while those without these traits eventually die off. For instance, if all of the food in an area was high up in the trees, only members of the species with long necks are able to eat and continue to live and reproduce. Those with shorter necks will not be able to eat and will eventually die off. Over time, the species will evolve to have long necks.
Hope this helps!