<u>Answer:</u> The amount of heat released is 56 MJ.
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
Given mass of
= 12 kg = 12000 g (Conversion factor: 1 kg = 1000 g)
Molar mass of
= 30 g/mol
Putting values in above equation, we get:

The chemical reaction for hydrogenation of ethene follows the equation:

By Stoichiometry of the reaction:
When 1 mole of ethane releases 140 kJ of heat.
So, 400 moles of ethane will release =
of heat.
Converting this into Mega joules, using the conversion factor:
1 MJ = 1000 kJ
So, 
Hence, the amount of heat released is 56 MJ.
The major visible difference between<span> the two are crystal size, </span>intrusive rocks<span> have a larger crystal/grain texture due to the slow cooling of magma below the earth surface which encourages the growth of larger crystals, while </span>extrusive rocks<span>, because of the rapid cooling at/above the earth's surface does the opposite. Hope I helped</span>
Answer:
metals are those element that have luster,malleable, ductile good conductors of heat and électricity, must have high melting and boiling points, and lose electrons in chemical reactions.
They are called guard rails