Answer:
0.0957 g
Explanation:
Half life is the time required by the substance to decay to half of its initial mass. Most often exponential decays of radioactive substances are explained by half life. Half life remains constant throughout the life of decay.
It is given as;
<em> N</em>(t) = N₀ (1/2)^t/t1/2
Where;
<em>N</em>(t) = Amount remaining after certain time
N₀ = The starting initial amount
t1/2 = Half life of given substance
Putting values,
<em> N</em>(t) = 98 × (1/2)^215/21.5
<em> N</em>(t) = 0.0957 g
Answer:
Precautions must be taken to remove all possibilities of fire or explosion.
Explanation:
Since Hydrogen is a very flamable or combustible gas, it is neccesary to avoid smoking, remove sourcs of sparks, flames or heat and hydrogen should be used in a well ventilated area.
I believe KI is not a a binary molecule.
Your welcome
Answer:
The correct answer is 596.5 kJ.
Explanation:
The mass of ethanol or C2H5OH mentioned in the question is 20 gm.
The molar mass of ethanol is 46 g/mol.
The moles of the compound can be determined by using the formula,
n = weight of the compound/molar mass
= 20/46 = 0.435 moles
It is mentioned in the question that standard heat of combustion of ethanol is 1372 kJ/mole, that is, one mole of ethanol is producing 1372 kilojoules of energy at the time of combustion.
Therefore, the energy liberated by completely burning the 20 grams of ethanol is 0.435*1372 = 596.5 kJ.
Answer:
1 oxygen 1 hydrogen hydrogen peroxide I think
