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
<u><em>what is frame of reference:</em>
</u><span>it is set of fixed points which are inter related on the basis of rest and motion..,, or an explanation of what an observer is doing..
</span><u><em>examples:</em>
</u><span>1 ,, if you are in motion and observing something then frame of reference is motion... and if you are at rest then frame of motion is rest...
</span><span>2 frame of reference may be place like if a passenger is sitting in a car then he is in motion with respect to the ground but he is at rest with respect to the car in which he is sitting ...
</span><span>3 also if a passenger is in car and he is tossing a coin and you are on the ground ,, then for passenger it is in vertical motion but for you it is in parabolic arc .. hence there are two different views for two persons for the same thing i.e coin... :)</span>
The power in watts is the energy in Joules used per second. This is:
P [W] = E[J] / t[s]
Solving for Energy:
E = P*t
We must convert the time to seconds knowing that 1 min = 60 s:
t = 6 min × 60 = 360 s
Finally:
E = P*t
E = 133 W * 360 s
E = 47880 J
<h2>The work of the runner is 47880 J</h2>
